Solberg, Lawrence A.

Abstract Background: Previous studies have proposed combination of various factors that predict poor mobilization after GCSF stimulation. However, there is no single clinical or laboratory test that reliably correlates with bone marrow reserve and PBPC mobilization. Peripheral blood CD34+ cell count (pCD34) reliably correlates with PBPC mobilization and yield but only after GCSF administration. Methods: We have prospectively followed 36 autologous PBPC transplant candidates, from the time of initial evaluation to transplant, to evaluate factors the correlate with bone marrow reserve and autologous PBPC mobilization. Results: The patients median age was 63 (range 26 – 76). 21 of the 36 patients were diagnosed with dysproteinemia, primarily multiple myeloma, 10 patients had non-Hodgkin’s lymphoma while the remaining 5 had other form of hematological malignancies. Our evaluation shows baseline platelet count prior to growth factor administration significantly correlate with total CD34+ cell yield (spearman: r = 0.64, p <0.001, Figure 1). In addition, daily platelet count during PBPC harvest correlate with CD34+ cell yield for the day (spearman: r = 0.6, p <0.001). Using multiple linear regression model (F = 19.1, p <0.001, R2 = 0.64), we have determined patients’ age (p = 0.03) and type of disease (p <0.001), in addition to platelet count (p<0.001), significantly correlate with total CD34+ cell yield. Further analysis showed low baseline platelet count predicts poor PBPC mobilization. Using Receiver Operating Curve (ROC), we have determined that platelet count of 174,000/ul was the best cut-off for collecting at least 2 million/Kg CD34+ cells with sensitivity of 81% and specificity of 78% and estimated correct classification of 81%. Even though pCD34 counts were slightly more sensitive and were better at identifying poor mobilizers in our cohort (best cut-off 10/ul, sensitivity 96%, specificity 67%, correct classification 89%), their clinical utility were diminished since the values were only known after GCSF administration. Conclusion: Baseline platelet count is a sensitive predictor of bone marrow reserve and can be used prior to growth factor administration to predict poor mobilization. Figure 1: Correlation of baseline platelet count and total CD34+ cell yield Figure 1:. Correlation of baseline platelet count and total CD34+ cell yield

Abstract Background: Scant data exists regarding the burden of fatigue and constitutional symptoms in patients with myeloproliferative disorders (MPDs) (essential thrombocythemia (ET), polycythemia vera (PV), and myelofibrosis with myeloid metaplasia (MMM)). Methods: An Internet based survey of MPD patients regarding clinical course, blood counts, constitutional symptoms, and fatigue (FACT-AN and Brief Fatigue Inventory (BFI)). Results: Patient Demographics: A total of 1179 MPD patients (median age 56; 41.4% male) internationally (76% USA: 50 states, 30 countries, 6 continents) responded to the survey. Self reported diagnoses were PV (35%), ET (26%), or MMM (39%). Clinical History: 1025 patients (87%) had undergone MPD therapy (drugs 70.5%, phlebotomy 44.1%, other 16%). Thrombosis (n=261, 22%), hemorrhage (N=272; 23%), and splenomegaly (N=478 (43%) were frequently reported. Blood tests (available in 917) showed 39% were anemic, 7% transfusion dependent. Symptoms: Fatigue, pruritus, night sweats and bone pain were present across the majority of MPD patients (see table). Additionally it was observed that these symptoms appeared with nearly equal frequency in PV as in MMM patients. However MMM patients displayed more advanced features (fevers, night sweats and weight loss). MPD Associated Constitutional Symptoms in 1179 Patients SYMPTOM PV (N=405) ET (N=304) MMM (N=456) MISSING (N=14) TOTAL (N=1179) P VALUE Fatigue 344 (84.9%) 220 (72.4%) 381 (83.6%) 7 945 (81.1%) <0.0001 Pruritus 265 (65.4%) 120 (39.5%) 228 (50.0%) 3 613 (52.6%) <0.0001 Night Sweats 199 (49.1%) 123 (40.5%) 254 (55.7%) 4 576 (49.4%) 0.0002 Bone Pain 174 (43.0%) 125 (41.1%) 214 (46.9%) 4 513 (44%) 0.2480 Fevers 53 (13.1%) 26 (8.6%) 81 (17.8%) 2 160 (13.7%) 0.0013 Weight Loss 39 (9.6%) 22 (7.2%) 93 (20.4%) 0 154 (13.2%) <0.0001 Spleen Pain 17 (4.2%) 27 (8.9%) 30 (6.6%) 4 74 (6.3%) <0.0001 Fatigue (82% MPD linked) was significantly increased across all MPD subtypes compared to published controls for both the BFI (P<0.0001) and Fact-An (P<0.0001). Additionally 69% curtail social activity because of fatigue, 35% need assistance with activities of daily living, and 11% reported MPD associated medical disability. Fatigue strongly correlated with multiple MPD disease features including: anemia, bone pain, constitutional symptoms, pruritus, splenic pain, smoking, thrombosis, and hemorrhagic events (all p<0.0001). Interestingly, even in “asymptomatic” MPD patients (those without anemia, splenomegaly, or thrombohemorrhagic complications) (n=279)) 24% (41% PV, 31% ET, 28% MMM) described significant fatigue worse than published controls. Conclusions: Fatigue and other constitutional symptoms are a significant burden to MPD patients, despite current therapies employed. Additionally fatigue is also a significant problem even in MPD patients lacking other advanced disease features. Clearly, direct attempts to improve fatigue (through pharmacologic and non-pharmacologic interventions) are necessary.

Abstract Background: Little objective data exists regarding the impact that myeloproliferative disorders (MPDs) (essential thrombocythemia (ET), polycythemia vera (PV), and myelofibrosis with myeloid metaplasia (MMM)) have on quality of life. Methods: An Internet based survey of MPD patients regarding clinical course, co-morbidities (through the Charlson Co-Morbidity Index), fatigue (through two validated fatigue instruments (FACT-AN and Brief Fatigue Inventory (BFI)), and exercise tolerance (Godin Leisure-Time Questionnaire). Results: Patient Demographics: A total of 830 MPD patients (median age 56; 60.8% male) from a broad geographic distribution (77% USA: 50 states, 30 countries, 5 continents) responded to the survey. Self reported diagnoses were PV (N=272; 33%), ET (N=221; 27%), or MMM (N=329; 40%) for a median of 5 years (range (0–53). Clinical History: 708 patients (87%) had undergone treatment for their MPD (drugs 84.6%, phlebotomy 49.5%, other 16%). A history of thrombotic (n=195, 24%) or hemorrhagic events (N=214; 26%) were frequently reported. Blood tests (available in 597 a median 1.65 months prior to survey) showed 37% were anemic (7% transfusion dependent). Additionally, 347 (44%) had splenomegaly, painful in 21%. Symptoms: Frequent symptoms reported included fatigue (90%), pruritus (57%), night sweats (54%), bone pain (48%), undesired weight loss (15%), and/or fevers (15%). 41% felt restricted in their activities, and 89 (11%) were medically disabled secondary directly to their MPD. 82% of patients felt their fatigue was linked to their MPD. Additionally 69% curtail social activity because of fatigue, and 41% need some degree of assistance with activities of daily living. Charlson co-morbidity index demonstrated 722 (87%) had minimal co-morbidities strengthening the association between fatigue and their MPD. The burden of fatigue decreased from MMM to PV to ET respectively (p=0.0002). Results from both fatigue assessment tools (FACT-AN and BFI) were highly correlated. Fatigue (FACT-AN fatigue subscale) strongly correlated with multiple MPD disease features including: anemia, bone pain, constitutional symptoms, pruritus, splenic pain, hemorrhagic events (all p<0.0001) and thrombosis(p=0.01). Additionally, currently smoking (as opposed to being a prior smoker) was highly associated with increased fatigue (p<0.0001). Interestingly, even in “asymptomatic” patients (those without anemia, splenomegaly, or thrombohemorrhagic complications (n=187)) 73% (n=128; 40% PV, 32% ET, 27% MMM; p=N.S.) described moderate to severe MPD associated fatigue. Reported physical activity was diminished (Godin Leisure Score) between MPD patients and published norms, with 38% describing minimal to no exercise. Overall, 86% stated fatigue was the major obstacle to exercise. Conclusions: Fatigue is an extremely common problem in patients with MPDs despite current therapies, and a minimal burden of co-morbidities in the majority of patients. Fatigue is also common in patients lacking advanced MPD disease features, or thrombohemorrhagic complications. Clearly, direct attempts to improve fatigue (through pharmacologic and non-pharmacologic interventions) are necessary.

Abstract Abstract 349 Failure to collect enough CD34+ cells following poor hematopoietic progenitor cell (HPC) mobilization is generally thought to be due to marrow damage following previous therapies. However, marrow damage alone cannot account for all poor mobilizations since there are donors who have good marrow cellularity but fail to adequately mobilize. In addition, the relationship between CD34+ cell dose and engraftment rate is not linear, suggesting other factors play a role during engraftment. Previous animal studies suggest CD8+ T cells are important for CD34+ cell homing to the marrow. We hypothesized that CD8+ T cells have dual roles by inhibiting CD34+ cell mobilization and facilitating engraftment. To test our hypothesis, we followed 192 autologous HPC donors to assess the role of CD8+ T cells in HPC mobilization and engraftment. The median donor age was 58.5 years (range 18 – 76), and 110 of the 192 patients were males. Donors were diagnosed with plasma cell disease, primarily multiple myeloma, or non-Hodgkin's lymphoma. CD34+ and CD8+ T cell content in the patients' apheresis products were enumerated using flow cytometry, quantitative RT-PCR (qPCR) and immunohistochemistry. The median CD34+ cell/kg was 4.7 × 106. Patients were categorized as low, moderate or high mobilizers according to their total CD34+ cell collection quartile distribution: <3.7, 3.8 – 5.5 and ≥5.6 × 106/Kg respectively. We found that HPC products from low mobilizers contained significantly more CD8+ T cells (median 1.25 × 108/Kg) than HPC products from moderate and high mobilizers (Table 1 p = 0.04). Therefore, the ratio of CD8+ T cells to CD34+ cells was 4 – 8 folds higher in low mobilizers than in moderate and high mobilizers. Moreover, CD8 antigen expression measured using qPCR, normalized with 18s ribosomal RNA, was significantly higher in low mobilizers than in moderate or high mobilizers. Similar analysis with CD4+ T cells did not demonstrate significant correlation with mobilization. To assess the role of CD8+ T cells in HPC mobilization, we purified CD8+ T and CD34+ cells from both low and moderate or high mobilizers. Using chemotaxis assay, we assessed the effect of CD8+ T cells on CD34+ cell migration away from high stromal cell derived factor (SDF1-a) concentrations. Purified CD34+ cells were plated in bone marrow epithelial cell coated trans-wells and co-cultured with purified CD8+ T cells at 1:2 and 1:5 ratios in the presence of SDF-1a at 0, 200 and 400ng/ml concentrations. Cells that migrated through the micro-pores of the trans-well into the lower wells were enumerated and analyzed. Our studies showed CD8+ T cells inhibit migration of CD34+ cells in-vitro independent of SDF1-a concentration. (Figure 1) The inhibitory properties of CD8+ T cells were more pronounced on CD34+ cells from low mobilizers than on CD34+ cells from moderate or high mobilizers. We also assessed if CD8+ cell content was associated with days to neutrophil engraftment. Our analysis showed the higher the CD8+ T cell content per unit CD34+ cell, the faster the rate of neutrophil engraftment. In summary, HPC products from low mobilizers contained significantly higher numbers of CD8+ T cells. CD8+ T cells, independent of SDF1-a concentration, significantly inhibited migration of purified CD34+ cells. In addition, CD8+ T cell content per unit CD34+ cell was inversely proportional to the time to neutrophil engraftment. These findings suggest CD8+ T cells may play dual roles by inhibiting CD34+ cell mobilization and facilitating its homing and engraftment. Table 1 Association of CD8+ T cell number with CD34+ cell mobilization capacity Mobilization Quartiles Low Moderate High p-value Median CD34+ Cell × 106/Kg 3.03 4.55 6.73 <0.001 Median CD8+ T cell × 108/Kg 1.25 0.50 0.33 0.04 CD8+ T: CD34+ cell ratio 41 11 5 Figure 1 Figure 1. Disclosures: No relevant conflicts of interest to declare.