Oken, Martin M.

Abstract H-MM affects about 40–50% of patients, and a similar proportion of MGUS/SMM. The genetic evolution of the disease and the clinical implications of the co-existence of 13q- or t(14q32) are unknown. We conducted a global survey of genetic abnormalities in H-MM in order to describe genetic evolution pathways. H-MM cases from the Mitelman cancer genetic database were combined with cases from the Mayo Clinic MM genetic database. All abnormalities (regional/whole chromosome gains/losses, breakpoints and translocations) were plotted against a 344-chromosome band profile created in a matrix format, and the number of genetic abnormalities per tumor (NAPT) logged. The abnormalities present in more than 5% of tumors were considered recurrent and each karyotype was scored for the presence or absence of each of the recurrent abnormalities. To investigate the temporal pattern of acquisition of genetic abnormalities, all tumors with a given abnormality were selected and the distributions of NAPT plotted. The modes of these distributions were used as a value of ‘lateness’, referred to as time of occurrence (TO). The impact of co-existence of 13q- and t(14q32) on progression free survival (PFS) and overall survival (OS) in H-MM was determined for MM patients entered into an Eastern Cooperative Oncology Group chemotherapy trial. Four hundred and sixty-nine H-MM patients were included in the karyotypic analysis. The median chromosome number was 53 (range 48–74) and the median NAPT was 10 (range 1–25). The distribution of NAPT revealed a normal distribution, suggesting an obligatory acquisition of a given number of genetic abnormalities. The most common abnormalities were trisomies of chromosomes 3,5,7,9,11,15,19 and 21 affecting a third or more of the patients. Deletions and abnormalities of even-numbered chromosomes occur in 20% or less of patients. None of the more than 300 specific translocations detected were recurrent. However, 5 translocation breakpoints were recurrent including 14q32, 8q24 and 11q13. TO analysis suggest that for H-MM, the trisomies are early genetic events, translocations occur midway and deletions tend to be later events. Amongst the trisomies, correlation analysis does not suggest a particular order of acquisition. Clustering analysis using principal component analysis suggests that in H-MM, IgH translocations are secondary events associated with disease evolution rather than defining unique biological entities. Consistent with this, survival of H-MM patients is not affected by 13q- status but is negatively impacted by the presence of t(14q32) especially those with unknown partners (p<0.05). The data presented suggest that H-MM fit a proposed aneuploid model of cancer due to auto-catalytic chromosome reassortment (Duesberg et al Cell Cycle2003:2:202–210). The presence of tumor specific trisomies and the apparent similar phenotype induced by various combinations of trisomies are consistent with this model.

Abstract Background: Syndecan-1 (CD138) is a heparan sulfate bearing proteoglycan found on various epithelial cells as well as on B lineage cells depending on its stage of development. Syndecan-1 (CD138) is abundantly expressed by plasma cells, especially myeloma cells. The extra cellular domain along with the heparan sulfate side chains can be cleaved off the cell surface and can be detected in the serum as soluble syndecan. Syndecan possibly plays a multifunctional role in the biology of myeloma. It has been shown to be an independent prognostic factor in patients with multiple myeloma. It has also been shown to promote myeloma cell growth through different mechanisms. Its expression has also been suggested to correlate with bone disease in MM. Methods: In this study we studied serum levels of soluble syndecan in newly diagnosed MM patients enrolled in the Eastern Cooperative Oncology Group (ECOG) E9486 and its associated correlative laboratory clinical trial E9487. We evaluated the prognostic value of syndecan in MM and its relationship to other known prognostic factors for this disease. In addition, syndecan levels were correlated with clinical and laboratory markers of bone disease. Results: A total of 501 patients were studied and the median serum syndecan-1 was 158 ng/mL. Syndecan levels correlated positively with other prognostic factors and markers of tumor burden such as β2-microglobulin (correlation coefficient 0.3; P <0.00001), labeling index (0.25; <0.0001), creatinine (0.23; <0.0001), soluble IL6 receptor (0.3; <0.0001), BM plasma cell percentage (0.16; <0.0006), and disease stage (P=0.0007). Significant differences in the overall and progression free survival was found between two groups of patient separated using the median value as cut-off. The High syndecan group had a median overall survival of 36.3 months compared to 49.3 months for the low syndecan group (P < 0.0001). Similarly, the high syndecan group had progression free survival of 25.4 months compared to 33.5 months for the low syndecan group (P < 0.0001). In a proportional hazards model including syndecan-1 as well as labeling index, β2M, Platelet count, IL-6R, syndecan-1 retained its prognostic value for overall survival (HR 1.3, P = 0.021). Syndecan levels were correlated with various bone markers including C-terminal telopeptide of type I collagen (ICTP), osteocalcin (OC), C-terminal type I procollagen (PICP), bone-specific alkaline phosphatase (BAP), and tartrate resistant alkaline phosphatase (TRAP) and were found to correlate only with ICTP (0.25, P < 0.0001). No correlation was found between clinical markers of bone disease including presence of lytic lesions, osteoporosis and pathologic fractures on X-rays or bone pain. Conclusion: In this large study, we once again confirm the prognostic value of serum syndecan-1 levels in large group of patients with newly diagnosed myeloma. Syndecan-1 level correlates with other disease markers. Syndecan levels also correlated with ICTP, a marker of bone turnover, though no strong correlation was found between syndecan levels and clinical markers of myeloma bone disease. The biological basis of these finding needs further evaluation.

17516 Background: The p53 tumor suppressor is commonly inactivated by mutations. Even in tumors without mutations, there are defects in the response to p53 activation. In MM, the prognostic significance of p53 mutation is unknown, while there has been no systematic study of p53 function. We seek to address these issues in this study. Methods: p53 mutation was studied by conformation sensitive gel electrophoresis with primers encompassing exons 1 to 10 followed by sequencing of DNA fragments with altered electrophoretic pattern in newly diagnosed MM patients entered into ECOG E9486 trial where patients were randomized to receive variations of melphalan-based conventional chemotherapy (VBMCP). Fisher’s exact tests were used to compare variables between patients. Kaplan-Meier survival curves were compared using the log-rank test. To investigate p53 function, we analyzed the expression of p53, and 3 of its transcriptional targets, APAF1, p21 and MDM2, in a separate cohort of 15 normal plasma cells (PC), 14 MGUS, 13 smoldering myeloma (SMM) and 101 MM (73 new and 28 relapsed) from the Mayo Clinic who had gene expression profiling performed on the Affymetrix U133A chip (Santa Clara, Ca). Results: Two hundred and sixty-eight patients had enough materials for study and were included in the analysis. The prevalence of p53 mutation was 3% (n = 9). Five of the 9 patients (56%, p = 0.001) with mutations also had p53 deletion (studied by fluorescent in-situ hybridization) resulting in bi-allelic loss of p53. Soft tissue plasmacytomas (37% v 7%, p = 0.018), and among the common translocations, t(4;14) and t(14;16) (50% v 18%) were more common in patients with p53 mutations. Despite similar response to treatment, those with p53 mutation had very short OS (16.7 v 41.4 months, p < 0.001). There was induction of p53 expression in MGUS and SMM with concurrent induction of APAF1, p21 and MDM2 whereas loss of this pattern was frequent in MM (45% in new MM and 60% in relapse MM compared to 15% in MGUS/SMM (p = 0.03)). Conclusions: p53 mutations are relatively rare in newly diagnosed MM patients but portend a short survival. However, functional abnormalities of p53 are prevalent and may be important in progression from MGUS/SMM to MM. [Table: see text]

Abstract We studied the prognostic significance of plasmablastic (PB) multiple myeloma (MM) in Eastern Cooperative Oncology Group Phase III trial E9486. Two reviewers independently reviewed 453 cases. They agreed on 37 PB (8.2%) cases and 416 non-PB cases, achieving an 85% concordance (P < .0001). These PB cases had significantly lower hemoglobin and serum albumin levels, higher calcium and β 2-microglobuin levels, and higher percentage BM plasma cells (PC) by immunofluorescence. They had higher bone marrow PC labeling indices, higher serum soluble interleukin-6 receptor (sIL-6R) levels, and a higher probability of ras mutations. Three treatment regimens were used: vincristine, bis-chloro-ethyl nitrosourea (BCNU) melphalan, cyclophosphamide, and prednisone (VBMCP) alone; VBMCP with added cyclophosphamide (HiCy); or recombinant interferon α 2 (rIFNα2). Although the numbers are low, patients with PB had a significantly lower response rate versus non-PB MM when treated with VBMCP (treated, 47.1% v nontreated, 66.5% [P = .015]). Patients with nonresponding PB had a significantly higher progression rate than non-PB cases (30.6%v 11.8% [P < .0001]), especially with VBMCP alone (35.3% v 15.8% [P = .002]), and with added HiCy (37.5% v 9.8% [P < .0001]), but not with added rIFNα2. Event-free and overall survival of PB MM was shorter (median years, 1.1 v 2.7 and 1.9 v 3.7, respectively [P < .0001 for both]). In multivariate analysis, PB classification was also highly prognostic. There is no survival difference between the patients who were classified as PB by both reviewers versus patients classified as PB by only one reviewer. We conclude that PB MM is a discrete entity associated with more aggressive disease and shortened survival. Tumor cell rasmutations and increased sIL-6R may contribute to a higher proliferation rate and reduced survival. There were significant improvements in response and progression with the addition of HiCy and rIFNα2 to VBMCP, but the numbers were small and improved survival could not be shown.

Recent analyses of circulating blood B cells in myeloma have generated controversy concerning the exact levels of these cells and whether they may represent circulating clonal tumor B cells. Previous reports suggested that CD19+ B cells are markedly increased in myeloma patients and that this population shares clonotypic rearrangements with the malignant plasma cell. We studied the numbers of CD19+ B cells by flow cytometry in previously untreated newly diagnosed myeloma patients in Eastern Cooperative Oncology Group (ECOG) phase III trial E9486. There were 628 patients who were eligible for the clinical protocol E9486, but of these 521 were also entered on the companion laboratory study (E9487) and had CD19 data. In comparison with normal controls, the myeloma patients exhibited a marked heterogeneity in the number of circulating CD19+ B cells as detected by flow cytometry. Approximately 20% of patients had significantly increased levels of circulating CD19+ B cells. However, the total CD19+ blood population from myeloma was not significantly different from the median of age-matched, normal controls. Analysis of CD19+ blood cells in relationship to circulating clonal cells was done in 13 myeloma patients using a clonotypic, quantitative allele-specific oligonucleotide-polymerase chain reaction (PCR) assay. No correlation was found between the numbers of CD19+ B cells (range, 5% to 51%) and PCR estimates of the number of clonal cells in the peripheral blood (range, .009% to 3.6%). Low CD19+ B-cell level (<125 μL) was associated with clinical stage III (P = .033). A significant relationship exists between higher levels (≥125/μL) of CD19 cells and longer overall survival (P < .0001). In addition, high CD19 levels also predicted a clinical response and longer event-free survival. There was a strong inverse association between the level of CD19 values at diagnosis and infections within the first 2 months of diagnosis. Importantly, the number of deaths related to infections was significantly greater in the low versus high CD19 group (P < .0202). Also, CD19 is an independent prognostic factor in addition to plasma cell labeling indices, β2 -microglobulin, hemoglobin, and plasmablastic morphology. Patients with infections were more likely to have low levels of CD19+ cells. In summary, higher CD19+ cell levels are a favorable prognostic sign with no apparent relationship to circulating tumor cells. In addition, this analysis strongly suggests that low peripheral blood levels of CD19+ cells are an adverse prognostic sign in myeloma. The CD19+ cell levels in myeloma patients is an important parameter in the overall assessment of these patients.

We studied the prognostic significance of plasmablastic (PB) multiple myeloma (MM) in Eastern Cooperative Oncology Group Phase III trial E9486. Two reviewers independently reviewed 453 cases. They agreed on 37 PB (8.2%) cases and 416 non-PB cases, achieving an 85% concordance (P < .0001). These PB cases had significantly lower hemoglobin and serum albumin levels, higher calcium and β 2-microglobuin levels, and higher percentage BM plasma cells (PC) by immunofluorescence. They had higher bone marrow PC labeling indices, higher serum soluble interleukin-6 receptor (sIL-6R) levels, and a higher probability of ras mutations. Three treatment regimens were used: vincristine, bis-chloro-ethyl nitrosourea (BCNU) melphalan, cyclophosphamide, and prednisone (VBMCP) alone; VBMCP with added cyclophosphamide (HiCy); or recombinant interferon α 2 (rIFNα2). Although the numbers are low, patients with PB had a significantly lower response rate versus non-PB MM when treated with VBMCP (treated, 47.1% v nontreated, 66.5% [P = .015]). Patients with nonresponding PB had a significantly higher progression rate than non-PB cases (30.6%v 11.8% [P < .0001]), especially with VBMCP alone (35.3% v 15.8% [P = .002]), and with added HiCy (37.5% v 9.8% [P < .0001]), but not with added rIFNα2. Event-free and overall survival of PB MM was shorter (median years, 1.1 v 2.7 and 1.9 v 3.7, respectively [P < .0001 for both]). In multivariate analysis, PB classification was also highly prognostic. There is no survival difference between the patients who were classified as PB by both reviewers versus patients classified as PB by only one reviewer. We conclude that PB MM is a discrete entity associated with more aggressive disease and shortened survival. Tumor cell rasmutations and increased sIL-6R may contribute to a higher proliferation rate and reduced survival. There were significant improvements in response and progression with the addition of HiCy and rIFNα2 to VBMCP, but the numbers were small and improved survival could not be shown.

Abstract Abstract 3017 Introduction: Multiple myeloma (MM) is a malignancy of clonal plasma cells with resulting in an increase production of ineffective immunoglobulins with suppression of non-involved immunoglobulins. Patients with MM are at increased risk of infectious complications, particularly to those organisms in which opsonization is one of the key defense mechanisms, e.g. strep and staph infections. Treatment of MM is virtually always associated with further immunosuppression, at least in the immediate term, until the malignant clone is eradicated and normal immunoglobulins are produced. Rationale: Due to further compromise of an already incompetent immune system by initial chemotherapy and the previous suggestion (Oken et al Am J Med 1996; 100:624-628) that prophylactic antibiotics may reduce infectious complications, this study was designed to evaluate the impact of prophylactic antibiotics on the incidence of serious bacterial infections during the first two months of treatment. Methods: Pts with untreated MM receiving chemotherapy were randomized on a 1:1:1 basis to receive either a daily ciprofloxacin (C; 500 mg), trimetheprim-sulfamethoxazole (T; DS bid) or observation (O) for the first 2 months of treatment. Pts were evaluated for serious bacterial infection (grade 3 or 4) during the first two months of myelotoxic/suppressive therapy. Secondary endpoints (EP) included: incidence of non-bacterial infections, resistant organisms due to prophylaxis, the incidence of infection the third month OFF of antibiotic prophylaxis and whether protection against infection is associated with an improved response rate. Results: From July 1998 to January 2008, 212 untreated, symptomatic MM pts being treated with myelotoxic/suppressive chemotherapy were randomized to C (n=69), T (n=76) or O (n=67) for the first 2 months of treatment. The incidence of serious infection (&gt; grade 3 ECOG toxicity criteria and/or hospitalization) was comparable among groups: C=10 (14.7%), T=5 (6.9%), O=9 (14.5%); p= 0.268 which was the primary EP. The incidence of any infection during the first 2 months was also comparable (20% vs 23% vs 22%, respectively, p=0.910). There were 25 grade 2 infections and 4 grade 3 infections involving respiratory (n =13), sepsis/bacteremia (n = 4), and urinary (n =3), joint/bone (n =2), unknown (n =2) or various GI tract (n = 5) and skin (n =1). Eight pts expired within the first 2 months: 2 from MM, 3 cardiac, 2 respiratory, 1 renal (unrelated to MM or Rx) occurring in the C (4), T (1), O (2). Secondary EPs failed to show a difference in the incidence of serious bacterial infection during the third month in the absence of prophylaxis (C=3%, T=4%, O=2%; p=0.874), development of resistant infections, initial response to therapy or overall survival. Conclusions: The use of prophylactic antibiotics did not decrease the incidence of serious infection (&gt; grade 3 and/or hospitalization) nor of any infection within the first 2 months of treatment. Infection prophylaxis did not affect the incidence of infection upon completion of 2 months of therapy (nor, ultimately, at any time during the subsequent 2 years), the response to therapy or to overall survival. Incidentally, there were no documented cases of PCP despite the assumption that MM pts, with compromised immune systems, are more susceptible. The incidence of serious infections in this study, in which few patients received novel agents, is comparable to that observed in more modern regimens even in the presence of mandated/recommended prophylactic antibiotics. Utilizing either lenalidomide plus dexamethasone or clarithromycin, lenalidomide and dexamethasone resulted in &gt; grade 3 infectious complications in 16.7% and 9.7%, respectively, as reported by the Mayo Clinic and Cornell groups, respectively (Gay et al Am J Hematol, in press). Furthermore, in the ECOG E4A03 randomized trial of lenalidomide plus either high dose dexamethasone (LD) or low dose dexamethasone (Ld) in which prophylactic antibiotics were recommended, the incidence of &gt; grade 3 infectious complications were 9.4% and 6.4%, respectively (Rajkumar et al Lancet Oncol 2010; 11: 29–37). We conclude that routine use of prophylactic antibiotics should not be mandated for patients receiving induction chemotherapy. Prophylactic antibiotics should be considered on a case-by-case basis after analyzing the potential infection risk in individuals. Disclosures: No relevant conflicts of interest to declare.

Abstract Background Extramedullary disease (EMD) of acute myeloid leukemia (AML) was described decades ago but the incidence of this phenomenon and its prognostic impact are not clear. It is also uncertain whether every site of EMD has the same significance. This study explored these questions using a large cohort of AML patients treated on consecutive Eastern Cooperative Oncology Group (ECOG) frontline clinical trials. Methods For AML patients enrolled into ECOG clinical trials, the presence of EMD was captured at baseline on case report forms. From patients with newly diagnosed AML, age 15 and above, who were treated on 11 consecutive different clinical trials, we identified those with or without EMD, defined by physical examination, laboratory findings and imaging, without necessarily a biopsy. We used descriptive statistics to summarize patient and disease characteristics. Univariate analyses of potential prognostic factors were done. The Kaplan-Meier method was used to estimate median overall survival (OS) within each prognostic category and differences were explored using the log-rank test. Cox proportional hazards models were used to examine the effect of one-unit increases in continuous variables on OS and for multivariable analyses. Multivariate models were built using backward selection. Factors (or groups of factors) significant at the 0.10 level in univariate analyses were tested for inclusion in the model, and retained if they were significant at the 0.05 level. Results Of the 3,522 patients enrolled in 11 different AML clinical trials, we excluded 281; for diagnosis of other types of leukemia (n=220), no EMD evaluation at baseline (n=41) or no survival data (n=20). The overall incidence of EMD was 23.8% (770 out of the remaining 3,241 patients). The sites involved were: lymph nodes 367 (11.3%) patients, spleen 234 (7.2%), liver 173 (5.3%), skin 146 (4.5%), gingiva 104 (3.2%), central nerve system (CNS) 32 (1%), peripheral nerve system (PNS) 8 (0.2%) and other sites 134 (4.1%). In 65 cases (8.4%) EMD was confirmed by biopsy. Most of the patients (64.4%) had only one site of EMD, 163 (21.2%) had 2 sites, 75 (9.7%) - 3 sites, 28 (3.6%) - 4 sites, and 4 patients (0.5%) each had 5 or 6 sites. EMD patients compared to those without EMD; tend to be younger (median age 45.7 vs 52.9 years); male (57.7% vs 52%); poorer ECOG performance status (76.4% with ECOG 0-1 vs 85.9%) and with higher white blood cell count (WBC) at diagnosis (median of 41.6/µl vs 10.2/µl). In univariate analysis, having EMD was associated with a shorter OS (P=0.006). Examination of individual EMD sites revealed that skin (P=0.002), spleen (P=0.0002) and liver (P=0.0007) but not CNS (P=0.35), PNS (P=0.53), nodal involvement (P=0.85) and gingival hypertrophy (P=0.14), were associated with poorer OS. Using proportional hazards models for continuous factors, each additional site of EMD conferred a 9.4% increase in the risk of death. In a multivariable model, after adjusting for known prognostic factors (such as: age, WBC count and cytogenetic risk group), the presence of EMD, number of EMD sites and any specific EMD site were not independently prognostic. Of 165 patients with known favorable cytogenetics EMD was present in only 22 patients (13%). This group appeared to have a worse prognosis, but the numbers are too small for a definitive assessment (figure 1). Conclusions Extramedullary disease is common in newly diagnosed AML with an incidence of almost 24%, but CNS involvement is very rare (0.95%). In contrast to published data, no site of EMD was found to have an independent prognostic impact in multivariate analysis. This large dataset emphasizes the importance of evaluating large number of patients and considering all known risk factors in the multivariate analysis. Disclosures: No relevant conflicts of interest to declare.

Abstract Although multiple myeloma is clinically defined as the accumulation of clonal, malignant plasma cells in the bone marrow, the disease shows significant heterogeneity with regard to morphology, progression and therapeutic response. Our hypothesis is that this heterogeneity likely is due, in part, to germline genetic polymorphisms that contribute significantly to an individual’s disease course and response. In particular, individuals deficient in the repair of DNA damage are not only at high risk for developing cancer, but also could show DNA repair dependent responses associated with DNA damaging therapeutic agents. In this study we examined the association of functional genetic polymorphisms in the DNA repair genes, XRCC1 (SNP positions 280, 399) and ERCC2 (SNP positions 312, 751), with toxicities and clinical outcomes in the ECOG, 3 arm chemotherapeutic trial, E9486 [A-VBMCP, B-VBMCP+Cylophosphamide, C- VBMCP+interferon]. DNA from 359 patients was genotyped and examined for association with response, toxicities, blood counts, bone pathology, and survival parameters. Notably, in the interferon arm of the trial significant associations were observed in progression free survival and polymorphisms of XRCC399 (AA median survival 51 months versus AG/GG median survival of 33 months; p=,008), ERCC751 (AA/AC median survival 33 months versus CC median survival of 48 months; p=.05), and ERCC312 (AA median survival 49 months versus AG/GG median survival of 34 months; p=.02). Hazard ratios ranged form 1.7 to 2.05 for survival differences associated with DNA repair genes in this arm. Interestingly, T cell counts are known to be impacted by interferon; and DNA repair polymorphisms in this arm were also associated with CD8+ T cell counts. While this represents a single arm of one clinical trial, it is intriguing to consider the impact of genetic polymorphisms on DNA repair in light of chemotherapeutic agents that may affect cells of the immune system. Previous studies from the ECOG Myeloma Committee of the E9486 trial show highly significant associations of survival and immune status in myeloma patients. Our results suggest genetic polymorphisms in DNA repair genes may influence clinical outcome in certain therapeutic regimens. Genetic polymorphisms in these DNA repair genes are currently being completed in 800 patients of the SW9321 SWOG/ECOG intergroup trial and additional association studies will be included in the presentation.

AbstractRecent analyses of circulating blood B cells in myeloma have generated controversy concerning the exact levels of these cells and whether they may represent circulating clonal tumor B cells. Previous reports suggested that CD19+ B cells are markedly increased in myeloma patients and that this population shares clonotypic rearrangements with the malignant plasma cell. We studied the numbers of CD19+ B cells by flow cytometry in previously untreated newly diagnosed myeloma patients in Eastern Cooperative Oncology Group (ECOG) phase III trial E9486. There were 628 patients who were eligible for the clinical protocol E9486, but of these 521 were also entered on the companion laboratory study (E9487) and had CD19 data. In comparison with normal controls, the myeloma patients exhibited a marked heterogeneity in the number of circulating CD19+ B cells as detected by flow cytometry. Approximately 20% of patients had significantly increased levels of circulating CD19+ B cells. However, the total CD19+ blood population from myeloma was not significantly different from the median of age-matched, normal controls. Analysis of CD19+ blood cells in relationship to circulating clonal cells was done in 13 myeloma patients using a clonotypic, quantitative allele-specific oligonucleotide-polymerase chain reaction (PCR) assay. No correlation was found between the numbers of CD19+ B cells (range, 5% to 51%) and PCR estimates of the number of clonal cells in the peripheral blood (range, .009% to 3.6%). Low CD19+ B-cell level (&lt;125 μL) was associated with clinical stage III (P = .033). A significant relationship exists between higher levels (≥125/μL) of CD19 cells and longer overall survival (P &lt; .0001). In addition, high CD19 levels also predicted a clinical response and longer event-free survival. There was a strong inverse association between the level of CD19 values at diagnosis and infections within the first 2 months of diagnosis. Importantly, the number of deaths related to infections was significantly greater in the low versus high CD19 group (P &lt; .0202). Also, CD19 is an independent prognostic factor in addition to plasma cell labeling indices, β2 -microglobulin, hemoglobin, and plasmablastic morphology. Patients with infections were more likely to have low levels of CD19+ cells. In summary, higher CD19+ cell levels are a favorable prognostic sign with no apparent relationship to circulating tumor cells. In addition, this analysis strongly suggests that low peripheral blood levels of CD19+ cells are an adverse prognostic sign in myeloma. The CD19+ cell levels in myeloma patients is an important parameter in the overall assessment of these patients.