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e19538 Background: Chronic neutrophilic leukemia (CNL) is a rare and aggressive myeloproliferative neoplasm with poor survival. No standard of care exists. Case reports describe allogeneic stem cell transplantation (ASCT) as the only curative therapy. Using the National Cancer Database (NCDB), we studied prognostic factors and survival outcomes of CNL. Methods: Patients diagnosed in 2004-2015 were included. 9963/3 was the ICD-O-3 code. Overall survival (OS) was analyzed using the Kaplan-Meier method. Hazard ratios (HR) with confidence intervals (CI) were calculated using Cox proportional hazards model. Variables significant in univariate analysis were included in a multivariate analysis. Data on incidence was obtained from the Surveillance, Epidemiology, and End Results Program (SEER) 21 Registries (2004-2015). The analysis was done with SEER*Stat software. Incidence was age-adjusted to the U.S. 2000 standard population. Results: A total of 121 CNL patients were in NCDB. The median age at diagnosis was 70 years (range 21-90); 74 (61%) were males and 107 (88%) were ≥ 50 years. The median follow up time was 5.8 years (interquartile range [IQR] 2.9-7.4). 32 (26%) had a Charlson Deyo score (CDS) > 1. 80 (70%) had government insurance, while 34 (30%) had private insurance. Median OS was 2.2 years (IQR 0.8-6.7). OS was 70% at 1 year, 29% at 5 years, and 11% at 10 years. The year of diagnosis was not associated with improved OS (HR: 0.95 (95% CI: 0.88-1.02), p =0.14). 71 (59%) patients received chemotherapy. The median time to chemotherapy from the day of diagnosis was 15 days (IQR 7-35). The OS of those who received chemotherapy was 71% at 1 year and 27% at 5 years versus 69% and 32% at 1- and 5- years for those who did not ( p= 0.38). 2 patients received ASCT (age 52 and 61 years) as initial therapy and both were alive at 5 years. Factors predicting inferior OS on univariate analysis were age ≥ 50 years at diagnosis ( p= 0.005), male ( p< 0.001), CDS > 1 ( p= 0.038), and government insurance ( p= 0.004). The table shows the multivariate (MV) analysis. The overall incidence of CNL was 0.1 cases/1,000,000 individuals and did not change significantly from 2004-2015. The incidences by male, female, White, Black, and American Indian/Alaska Native were also 0.1 cases/1,000,000 individuals. Conclusions: OS and incidence of CNL have not changed over the years. Age ≥ 50 years, male gender, and use of government insurance predicted inferior OS. [Table: see text]

Abstract Introduction: The immunoglobulin free light chain (FLC) is the precursor protein of amyloid in primary systemic amyloidosis (AL). Historically, the ability to monitor the amyloid protein precursor has been crude. There is now a test that reproducibly measures serum levels of FLC. We evaluated the utility of this assay in patients with AL undergoing peripheral blood stem cell transplant (PBSCT). Methods: Between March 1, 1996 and July 31, 2004, 98 patients with AL undergoing PBSCT had serial FLC measurements performed either prospectively or on stored sera. Patients who died before their 100 day evaluation were excluded because response could not be estimated. FLC levels were performed using Freelite™ reagents on a Dade-Behring Nephelometer. In order to pool the data of the monoclonal kappa and lambda patients, the clonal free light chain was considered the involved] immunoglobulin free light chain for the purpose of these analyses and is henceforth referred to as FLC. The prognostic effects of the initial concentration and the extent of reduction of monoclonal FLC on survival were evaluated. Results: Pre-transplant, 94% of patients had an abnormal FLC ratio, with a median involved FLC of 152 mg/L [15.2 mg/dL]. Only 14% of 98 patients had a “measurable” serum M-spike (i.e. ≥ 10 g/L [1 g/dL]) on electrophoresis with a median of 1 g/L [0.1 g/dL]. Ten patients have died of their disease during a median follow-up time of 19.5 months, range 3.3 to 103 months. The 2- year and 4-year estimated survivals are 92% and 76%, respectively. Using the 75th percentile value of pre-PBSCT FLC (382 mg/L [38.2 g/dL]) as a grouping variable, there was a significantly higher risk of death 5.4 (95% confidence interval 1.5–19.3) in the patient quartile with the highest baseline FLC. Baseline FLC correlated with serum cardiac troponin T levels (rho 0.51, p&lt;0.0001), suggesting that high FLC levels are associated with more advanced disease. After PBSCT, the median percent reduction of FLC was 81%. The percent FLC reduction did not predict for survival, but the absolute level of FLC achieved after therapy did. The hazard ratio for death for not achieving a post-transplant FLC of 20 mg/L [2 mg/dL] post-transplant was 5.1 (95% confidence interval 1.1–24.1). Of 91 patients evaluable for complete response by EBMT criteria, 45 had a complete hematological response. Sixty-five percent of the patients achieving a FLC level of less than 20 mg/L [2 mg/dL] also had a complete hematologic response. Free light chain response as defined by a post transplant FLC level 20mg/L [2 mg/dL] or lower was a more powerful predictor of survival than complete hematologic response, as defined by the EBMT multiple myeloma criteria. Post-PBSCT FLC level only weakly predicted for organ response, but median follow-up for surviving patients is relatively short at 19.6 months. Conclusion: FLC measurements both pre- and post-PBSCT are important predictors of patient outcome.

Abstract Introduction: The association of amyloidosis with immunoglobulin light chain disorders is well recognized. It is less commonly appreciated that amyloidosis can be associated with IgM monoclonal gammopathies. One of the available therapies for treating amyloidosis is stem cell transplantation. It is unknown whether the clinical outcomes in patients with IgM amyloidosis differs from those patients with light chain amyloidosis. Patients: Among 242 amyloidosis patients receiving stem cell transplants 10 (4%) had an IgM monoclonal protein. Eight were Mλ. One was biclonal Mλ Mκ and one was biclonal Mκ Gλ. The age range was 56 to 71, median 64 years. Seven were men. The monoclonal protein ranged in size from 0.1 to 2.3 g/dL (median 1.2 g/dL). Patients were transplanted from 2 to 8 months (median 4 months) following histologic diagnosis of amyloid. The median time from the recognition of the IgM monoclonal protein to the diagnosis of amyloid was 1.3 months, but 2 patients, both of whom had overt Waldenström’s macroglobulinemia, were diagnosed 45 and 115 months respectively before amyloidosis developed. Of the cohort of 10, 3 fulfilled the criteria for symptomatic Waldenström’s macroglobulinemia. Results: Amyloid syndromes were recognized in the kidney, heart, peripheral nerve and liver in 8, 3, 3 and 1 patient, respectively. Of the 3 peripheral neuropathy patients one also had autonomic failure. Seven of the 8 renal amyloid patients were confirmed with a renal biopsy. Their urinary protein loss ranged from 0.1 to 9.5 g/24h with a median of 4.7 g/24h. Six of the 10 patients had single organ involvement, 3 had 2 organ involvement and 1 had 3 organ involvement. All 3 Waldenström’s patients had prior exposure to cytotoxic chemotherapy. Amyloid deposits were seen in the bone marrow, fat and lymph node in 6, 5 and 1 patient, respectively. Patients underwent from 1 to 7 (median 3) apheresis with a median CD34 yield of 4.5 x 106/kg. Conditioning was Melphalan at 140 and 200 mg/m2 in 2 and 8 patients respectively. Neutrophil engraftment 500/μL occurred between day 11 and 30 (median 14) and for platelets 20,000/μL between day 11 and 406 (median day 16). The median number of hospitalization days ranged from 0 to 32 (median 12). Nine of the 10 patients fulfilled criteria for a hematologic response and to date 3 of these 9 have also achieved an organ response, including normalization of urinary protein loss in 2 nephrotic patients and a greater than 50% reduction in urinary protein loss in the third. None of the patients with amyloid neuropathy responded. One of the patients with cardiac amyloid showed echocardiographic evidence of improvement. At this time 8 survive and 2 died; 1 a treatment-related death (day +40) and 1 of relapse post transplant with progressive amyloid at 45 months. The median follow-up of surviving patients is 29 months. Conclusion: The outcomes in patients with IgM amyloidosis following transplantation do not appear to be different from those with immunoglobulin light chain amyloidosis. There is no suggestion that the response rates are lower or that alternate conditioning schemes such as BEAM should be considered.

Abstract Introduction: Stem cell transplant is an increasingly widely applied technique for managing amyloidosis. As in multiple myeloma, the treatment would not be expected to be curative and patients would be expected to relapse in most instances. In addition, approximately one-third of patients fail to respond to initial therapy. The role of second transplantation in treatment failures or patients who relapse is reviewed. Patients: Of 242 patients undergoing high dose conditioning and stem cell transplantation for amyloidosis (AL) at the Mayo Clinic, 6 subsequently underwent a second transplant. Results: Patient 1, who had single organ renal amyloid nephrotic syndrome responded and relapsed at 73 months, received a second stem cell transplant achieving a hematologic complete response with normalization of a markedly elevated pre transplant free light chain (59 to 1.9 mg/dL) and is alive at 12 months. Patient 2 relapsed 42 months after transplant for single organ renal amyloidosis; the second stem cell transplant, has normalized his free light chain ratio reduced his urinary protein loss from 5450 to 1482 mg/day and he is alive 21 months following his second transplant (63 months overall). Patient 3 relapsed 34 months after a response of renal and cardiac amyloidosis. After transplant two, he failed to achieve a 50% reduction in his free light chain, began hemodialysis 7 months post transplant and died one year post transplant. Patient 4 with single organ cardiac involvement relapsed 30 months following his first transplant and died on day +5 of his second transplant of an acute pulmonary embolus. Patient 5 was a response failure after his first transplant, had a second transplant 35 months later, having failed Dexamethasone followed by Melphalan/Dexamethasone therapy, and died 3 months later of progressive disease. Patient 6 had single organ vascular involvement manifest by calf and thigh claudication and failed to respond with his first transplant with a persistently elevated free light chain. The second transplant was performed six months after the first without further free light chain reduction and persistent claudication at 11 months. Conclusion: Patients who failed to achieve a hematologic response after a first transplant appear not to benefit from a second course of high dose therapy. Among 4 patients who were previously responsive and relapsed, one achieved a hematologic complete response, one achieved a hematologic partial response, and two died. The two patients achieving a second hematologic response had the longest response duration (73 and 42 months) following their first transplant, and the second response presumably reflects favorable (indolent; non proliferative) biology of the underlying plasma cell dyscrasia. High dose therapy and stem cell transplant may be an effective salvage regimen for patients who responded to a first transplant and whose response lasted greater than 36 months.

Abstract Background: Overall prognosis in CMML is unfavorable. The only curative option is ASCT, yet the limited data available from the largest reported series, reports 2 year overall (OS) and disease free (DFS) survival of only 21% and 18%, respectively [Kroger et al, BJH 2002, 118: 67]. Data on DLI for CMML are generally restricted to case reports. We retrospectively reviewed our experience of ASCT and DLI for adults with CMML. Patients: Seventeen consecutive patients (11 males) with CMML underwent ASCT from 1992 to 2004. At transplant, median (range) age was 50 years (26–60), duration of disease 7 months (2.5–44), and bone marrow (BM) blast count 6% (1–58%). Prior to transplant, 11 had evolved into acute myeloid leukemia (AML). Of these, 10 received standard induction chemotherapy but only one achieved complete remission (CR); 5 had persistent CMML and 4 refractory AML. Karyotype at transplant was either normal (n=9) or revealed isolated monosomy 7 (n=4), complex (n=1), or single, nonrecurrent abnormalities. ASCT: Conditioning was Cytoxan/Total Body Irradiation in all but one who received a non-myeloablative (NMA) regimen (cladrabine/ATG/thiotepa). Stem cell source was HLA-identical sibling in 14 patients and unrelated in 3 peripheral blood (PB) in 7, BM in 8, or both in 2. Median BM mononuclear cell/kg dose was 2.3 (1.7–4.15) x 108 and PB CD34 cell/kg was 5.12 (0.94–7.29) x 106. Graft versus host disease (GVHD) prophylaxis was cyclosporin alone (n=3), with methotrexate (n=12), or prednisone (n=1) or was tacrolimus/methotrexate (n=1). Post-transplant course: All but one patient who died on day 11 of sepsis engrafted (sustained ANC &gt; 500) at a median of 19.5 days (13–31). CR was documented in 13 (76%) post-ASCT. Acute GVHD was grade II-IV (75%) and III-IV (37.5%) and chronic GVHD was extensive (n=37.5%). Seven (41%) demonstrated relapse or persistent disease at a median of 6 months (3–55.5) and 13 (76%) have died due to disease (n=6) or transplant related mortality (n=7). DLI: Six patients underwent DLI for morphologic (4 recurrent/persistent CMML, 1 early AML with extramedullary disease) or cytogenetic relapse (n=1), at a median of 19.5 days (6–52) post-relapse. Median BM blast count at DLI was 3% (1–22%). The median CD3+ cell dose infused was 30.45 x 107 cells/kg (11.2–45.5), given in a median of 3 infusions (range: 1–3). Four did not respond, but two (one with cytogenetic and one with morphologic relapse) achieved a durable CR of 15 months each, both had extensive CGVHD, from which one died of complications. The other relapsed but failed to respond to a second DLI and died of disease. Survival: For the entire cohort, median DFS and OS were 6 months and 7 months, respectively. At last follow up, 4 remain alive, 3 in continuous CR (18%), at 12, 29 (treated with the NMA regimen) and 116 months, respectively. Of the 3 patients surviving in remission, all had transformed to AML prior to ASCT and only one had achieved CR following induction chemotherapy. Multivariate analysis failed to demonstrate any significant effect of age, duration of disease, BM blast %, karyotype or induction chemotherapy on RFS or OS, likely reflecting the small numbers available for analysis. Conclusion: The current study demonstrates anti-CMML activity of both ASCT and DLI although overall outcome is less than encouraging and unpredictable. Novel approaches are needed.

Abstract BACKGROUND. Several studies have recently reported on the occurrence of a JAK2 V617F mutation in myeloid cells from the majority of patients with polycythemia vera (PV). The clinical relevance of this novel observation is currently under study. Similarly, there is limited information regarding the correlation of JAK2 V617F mutational status and neutrophil PRV-1 transcript level in PV, secondary polycythemia (SP) and other myeloproliferative disorders (MPD). METHODS. In a single institutional study, mutation screening for JAK2 V617F was performed in DNA derived from archived blood granulocytes from 63 consecutive patients with PV in whom current diagnostic criteria were strictly applied and diagnosis confirmed by bone marrow histology. Concomitant quantitative analysis of neutrophil PRV-1 expression was performed in 28 of the 63 patients and the results of both JAK2 V617F and PRV-1 analysis in these 28 patients were compared with those from another 22 patients with essential thrombocythemia (ET), 10 with myelofibrosis with myeloid metaplasia (MMM), 19 with SP, and 11 healthy volunteers. RESULTS. The 63 patients with PV were followed for a median of 33 months (range 3–324) from the time of initial diagnosis. During this period, 3 patients have died including 2 from acute myeloid leukemia (AML). Disease transformation into either AML or MMM has occurred in 2 and 4 patients, respectively. The median time from diagnosis to the time of mutation analysis was 12 months (range 0–306). JAK2 V617F was detected in 58 of the 63 patients with PV (92%; homozygous in 21%). The clinical phenotype of the 5 patients with wild-type allele was otherwise typical for the disease. A statistical comparison between JAK2 V617F heterozygotes (n=45) and homozygotes (n=13) in PV did not reveal significant associations in regards to age, gender, leukocyte or platelet count at diagnosis, disease duration, or the incidences of thrombosis or bleeding. However, JAK2 V617F homozygotes, compared to their heterozygote counterparts, displayed significantly higher hemoglobin level at diagnosis (p=0.001), increased incidence of pruritus (69% vs. 38%; p=0.04), and a higher rate of fibrotic transformation (23% vs. 2%; p=0.009). The overall (homozygous) JAK2 V617F mutational frequencies in the other study patients with ET, MMM, SP, and healthy controls were 55% (0%), 30% (0%), 0%, and 0%, respectively. The corresponding figures for increased PRV-1 expression in these patients were 18%, 20%, 21%, and 9% as compared to 89% in PV. In patients with either ET or MMM, the likelihood of detecting JAK2 V617F was significantly higher in the presence of an increased PRV-1 expression (83% vs. 38%; p=0.05). Similarly, in patients with PV, homozygous as compared to heterozygous JAK2 V617F correlated with higher levels of PRV-1 expression (p=0.07). CONCLUSIONS. The current clinical study demonstrates a mutant allele dose effect on erythrocytosis, PV-characteristic clinical features, and granulocyte PRV-1 expression in PV. Furthermore, compared to the PRV-1 assay, mutation screening for JAK2 V617F displayed greater specificity in distinguishing PV from SP.

Abstract Background: One of the utilities of molecular markers in hematological malignancies is their potential to predict response to drug therapy. Accordingly, we inquired about the effect of both cytogenetic profile and JAK2V617F mutational status on drug therapy response in myelofibrosis with myeloid metaplasia (MMM). Methods: Mutation analysis for JAK2V617 was performed in DNA derived from peripheral blood mononuclear cells, granulocytes, or both. Genomic DNA was amplified by PCR and fluorescent dye chemistry sequencing was performed using the same primers used for amplification (Levin et al. Cancer Cell2005;7:387). Abnormal cytogenetic findings were considered to be either favorable (sole 13q- or 20q- abnormalities) or unfavorable (other abnormalities) (Tefferi et al. BJH2001;113:763). Results: i. Patients and treatment: A total of 69 patients with MMM (median age 62 years, range 38–75; 47 males) received the following drugs as first-line therapy for either anemia or symptomatic splenomegaly; erythropoietin (Epo) alone or in combination with hydroxyurea (n=25), hydroxyurea alone (HU; n=17), interferon alpha (IFN; n=11), combination of thalidomide and prednisone (ThalPred; n=7), androgen preparations (Andro; n=5), and etanercept (n=4). ii. Results of cytogenetic studies and JAK2 mutation screening: Cytogenetic findings were abnormal in 35 patients (51%); favorable in 9 and unfavorable in 26. JAK2V617 mutation analysis revealed wild-type allele in 31 patients (45%) and either heterozygous (n=31) or homozygous (n=7) mutation in the remaining 38 patients (55%). iii. Correlation of response to cytogenetic/molecular markers: Overall, 17 patients (25%) achieved either a major (n=8) or minor (n=9) response in anemia from treatment with one of the aforementioned drugs. Regardless of either JAK2V617 mutational status or cytogenetic profile, treatment-induced responses in anemia were poor for IFN (0%) and HU (12%). In contrast, the best anemia responses were documented for ThalPred (57%), Andro (40%), and Epo-based therapy (32%). Among the 25 patients that received Epo-based therapy, all 3 patients with favorable cytogenetic abnormalities achieved major responses in anemia whereas such responses were seen in none of the 9 patients with unfavorable cytogenetic abnormalities and only 1 of 13 patients with normal cytogenetics (p=0.004). Furthermore, 3 of the 4 major responders were heterozygous for JAK2V617 and one carried the wild-type allele. In contrast, none of the 3 JAK2V617 homozygotes showed any type of response but all 3 also displayed unfavorable cytogenetics. None of the 7 ThalPred-treated patients carried favorable cytogenetics and yet 3 achieved major responses including one with unfavorable cytogenetics. JAK2V617 mutational status was heterozygous in 1 and wild-type in the other two. There were no major responses among the 5 Andro-treated patients despite the presence of favorable cytogenetic abnormalities in 2 patients. In order to investigate the relationship between cytogenetic profile and JAK2V617 mutational status further, we referred to an expanded database of 116 patients and found the incidence of unfavorable cytogenetics to be higher in JAK2V617 homozygotes compared to non-homozygotes (57% vs. 31%; p=0.16) Conclusion: The current study suggests clustering of favorable cytogenetic abnormalities in MMM with anemia response to Epo therapy and unfavorable cytogenetic abnormalities with homozygosity for JAK2V617 mutation.

Abstract Background Heparin-induced thrombocytopenia (HIT) is an immune-mediated drug reaction in which heparin-dependant IgG antibodies (HIT-IgG) to heparin-platelet factor 4 complexes form with the potential for platelet activation with resultant thrombocytopenia (HIT) and thrombosis (HITT). The frequency of HIT-IgG formation and clinically apparent HIT or HITT varies considerably, according to the patient population (surgical versus medical) and type of heparin (unfractionated [UFH] vs low molecular weight [LMWH]). One large prospective study showed a frequency of HIT-IgG formation of 7.5% with clinical HITT in 34.5% of these orthopedic patients receiving prophylactic LMWH and corresponding figures in cardiac surgery patients receiving UFH were 50% and 2%, respectively [Warkentin et al. Blood2000;96: 1703]. Due to daily exposure to heparin flushes (UFH) and prophylactic LMWH (to prevent venoocclusive disease) hematopoietic stem cell transplant (HSCT) recipients may be at risk for HIT/HITT. However, due to anticipated post-transplant thrombocytopenia, clinical cases of HIT/HITT may be overlooked. We retrospectively determined the incidence of HIT-IgG formation and its clinical significance in this population. Methods: HIT-IgG was measured retrospectively using a commercially available ELISA kit in samples collected from patients prior to conditioning therapy and on day 14 post-HSCT. Medical records were reviewed to in order to determine the clinical significance (development of clinical HIT/HITT) in those with detectable HIT-IgG. Patients Samples from a total of 103 HSCT recipients with hematologic malignancy (including 25 myeloma, 17 lymphoma, 16 AML, 14 amyloid, 10 MDS, 10 ALL, 8 CML and 3 CLL) were tested, of which 52 and 49 underwent allogeneic and autologous HSCT, respectively. All patients were exposed to UFH flushes during line care. In addition, all allogeneic recipients received prophylactic subcutaneous dalteparin 5000U daily beginning with conditioning until engraftment. Conditioning regimens included high dose melphalan (n=34), cyclophosphamide/TBI (n=30), carmustine, etoposide, cytarabine, melphalan (n=15), busulfan/cyclophosphamide (n=9), fludarabine/melphalan (n=10) and fludarabine/TBI (n=4). The median age was 51.5 years (20–72) and 68 were male. Results: The median platelet count prior to initiation of conditioning therapy and at day 14 was 157 × 109/L (range: 10–672) and 40 × 109/L (range: 9–289), respectively. Prior to conditioning, two of 103 (1.9%) patients had a positive HIT-IgG assay, that became negative in one and equivocal in the other by day 14 post-HSCT, and one patient had an equivocal HIT assay that became negative by day 14. All 3 were autologous recipients. None of the previously negative patients had a positive HIT-IgG assay at day 14, although 3 patients (2 autologous and one allogeneic) had an equivocal result of uncertain significance. No patients developed clinical or symptomatic thrombosis (HITT). Conclusion: In spite of frequent exposure to heparin, the frequency of seroconversion is low, and in those patients with preexisting HIT-IgG, no patient developed symptomatic thrombosis, including the 2 patients with positive HIT IgG assays prior to conditioning. The low frequency of HIT-IgG formation may reflect the profound immunosuppression of the conditioning regimens employed. Nevertheless, in this population, a high index of clinical suspicion must be maintained.

Abstract Background: The FIP1L1-PDGFRA fusion, an imatinib-sensitive molecular target, is detected in a subset of cases with moderate-to-severe eosinophilia (eosinophil count ≥1500/μL). Using 2 FISH strategies to detect loss of the CHIC2 locus as a surrogate marker of the FIP1L1-PDGFRA fusion, we previously found 14% of cases to be CHIC2-deleted when studying bone marrow smears from 81 adult patients with moderate-to-severe, non-reactive eosinophilia at our institution (Blood 2004, 104:3038–3045). Since then, the FISH test has been made available for routine clinical use both within our institution, and to external physicians as a mail-in test, for the workup of patients with eosinophilic disorders, including systemic mast cell disease (SMCD). Study design: FISH data, subsequent to the test’s introduction into routine clinical practice (from Nov. 2003), were retrospectively analyzed for CHIC2-deletion. Data from the initial pilot study of 81 patients was not used in this analysis (Table). The imatinib treatment analysis, however, included all CHIC2-deleted patients treated at our institution, including those from the pilot study (Table). Results: A total of 741 patients were studied in the post-pilot phase. Of these, 20 cases were found to be CHIC2-deleted, with an overall prevalence of 2.7% (Table). Of the 219 patients seen at our institution, 13 (all male) were found to be CHIC2-deleted (Table) (prevalence=5.9%), and of these, 10 have been treated with imatinib (100 mg/day starting dose) to date. Nine patients are evaluable for response - all achieved a complete clinical and histological remission (7 patients were tested by FISH post-treatment - all achieved cytogenetic remission). One patient received concomitant corticosteroids for co-morbidities and could not be evaluated for response. After a median follow-up of 24 months (range 17 to 39 months), all 9 patients continue to be in remission, with a normal eosinophil count. At last follow-up, one patient had discontinued imatinib and the others were on maintenance therapy at the following dose: 100mg/wk (n=1), 100mg BIW (n=1), 100mg TIW (n=2), 50mg QOD (n=1), and 100 mg/day (n=3). Conclusions: FIP1L1-PDGFRA prevalence in non-selected patients with eosinophilia is lower than anticipated from prior studies. Patients with FIP1L1-PDGFRA exhibit durable responses to imatinib therapy. It may be feasible to maintain some patients in remission on an empirically derived, intermittent schedule of low-dose imatinib. Pilot Data Post-pilot Data (n=741) Total Mayo samples Mayo samples Mail-in samples Number of Patients 81 138 603 822 Number CHIC2-deleted 11 2 18 31 Prevalence 14% 1.4% 3.0% 3.8% Number Imatinib treated 8 2 n/a 10

Abstract Background: Copper deficiency is an established cause of hematological abnormalities, traditionally described in malnourished infants and persons with malabsorption or short bowel syndromes, particularly those requiring long-term parenteral nutrition. With the recent increase in bariatric (weight reduction) surgery, acquired copper deficiency may be increasing in incidence but the diagnosis is frequently delayed. Methods: To outline the natural history of copper deficiency we searched the Mayo Clinic database and our heavy metals laboratory for patients diagnosed with low serum copper during the years 1974–2005. Copper deficiency was defined as a serum level &lt; 0.75 μg/ml. Results: We identified 123 patients with a low serum copper. 77 patients were excluded as the the hypocupremia was either transient or due to other factors such as Wilson’s disease. The remaining 46 patients were all symptomatic. 25 patients had hematological abnormalities, 20 of these patients also had neurological involvement. 5 had isolated hematological manifestations and 21 patients had isolated neurological findings, most commonly myeloneuropathy. 13 presented with anemia and leukopenia, 5 with pancytopenia, 6 with anemia and 1 with isolated neutropenia. In 10 of the 25 cases, a secondary contributing cause for the hematological findings was identified. These included possible anemia of chronic disease (4), renal insufficiency (2), iron deficiency (1), B12 deficiency (1), GI hemorrhage (1), and splenomegaly (1) while copper deficiency was the only identifiable cause in the remaining 15 patients. Hematological parameters at diagnosis are outlined in the table. 15 of the 25 patients with hematological manifestations had a history of GI surgery, including 6 patients who had bariatric surgery. The median time from surgery to diagnosis was 11.5 years (range 8 months - 45 years) and was shorter for bariatric surgery (10 years, range: 8 months - 25 years) than for non-bariatric surgery (18 years, range: 2–45 years). 1 patient had a history of excessive zinc ingestion, 1 had malabsorption secondary to chronic pancreatitis and 1 patient had celiac disease. In 7 cases, no explanation was found. 24 of 25 patients received treatment with oral or intravenous copper, 5 were lost to follow up. In 16 patients the hematologic parameters either improved significantly or normalized, while in the remaining 3 patients there was no improvement. Factors that may explain the lack of response in these patients included splenomegaly (1), renal insufficiency (1) and multiorgan illness (1). Conclusion: Copper deficiency is an increasingly frequent cause of hematological abnormalities, and can manifest with refractory cytopenias with or without associated neurological symptoms. Thrombocytopenia is relatively rare. Previous GI surgery, especially bariatric surgery, appears to be a major causative factor. Most patients will have an improvement in hematological parameters after copper supplementation. Recognition of copper deficiency is therefore assuming greater importance in view of the increasing frequency of bariatric surgery, ease of treatment and potential for irreversible neurological damage if diagnosis is delayed. Hematologic parameters at diagnosis HgB (g/dL) MCV (fL) WBC (x109/L) ANC(x109/L) Plts(x109/L) Median 10.6 99 3.0 1.25 215 Range 7.9-13.6 83.9-114.1 1-5.6 0.18-4.0 54-554