Our study suggests that low-dose rituximab and PEx are effective as front-line treatment for acute TTP; however, a prospective trial is needed to demonstrate whether low-dose rituximab is as effective as the conventional dose.

Background: Lumbar puncture (LP) is a hematology procedure that can require repeated attempts leading to traumatic LP (TLP), which has been related to the central nervous system (CNS) relapse. LP success can depend on the size and anatomy of the patient and the skill of the hematologist. The main objective was to determine the influence of body mass index (BMI) on LP outcomes. Materials and Methods: Adults with lymphoid malignancies requiring LP were included prospectively over one year; hematology residents performed most procedures. A 22-gauge Quincke needle was employed. Comparison between non-traumatic vs. traumatic LPs according to BMI, CNS relapse, and residents’ year was performed. Results: Fifty-four patients with a mean age of 31.5±15.57 years were included. Diagnosis was Acute Lymphoblastic Leukemia-B (74%), Acute Lymphoblastic Leukemia-T (13%) and Non-Hodgkin Lymphoma (13%). 227 LPs were performed, 121 (53.3%) successful, 98 (43.2%) traumatic, 11 (11.2%) TLPs were macroscopically detectable and 87 (88%) microscopic; 8 (3.5%) were dry-taps. Median time between punctures was 11 days (1-202). Median BMI was 25 (22.8-39.6). Main indication for LP was prophylactic (74.5%); 39.2% were performed by first-year, 35.2% by second-year, 19.6% by third-year hematology residents. No difference (p = 0.145) for a TLP was found among residents. A BMI ≥30 (p = 0.040), non-palpable intervertebral space (p = 0.001) and more than one attempt (p = 0.001) were significant for TLP. TLP was not associated with CNS relapse (p = 0.962). Conclusion: Obesity predicted a TLP. A traumatic puncture did not increase the risk of CNS relapse at one-year follow-up.

BACKGROUND Autologous stem cell transplantation (ASCT) is an effective treatment for patients with relapsing myeloma or lymphoma, diseases associated with unsuccessful peripheral blood stem cell (PBSC) collection. Plerixafor is a potent mobilizing agent, allowing more CD34+ cells to be obtained; however, the main obstacle for its use is its high cost. Our aim was to demonstrate that of the use of reduced doses of plerixafor (RD‐plerixafor) can be sufficient to collect at least 2 × 106/Kg CD34+ PBSC in patients with multiple myeloma (MM) or lymphoma undergoing ASCT. STUDY DESIGN AND METHODS Twenty patients were mobilized with filgrastim (10 μg/kg/4 days) plus a single dose of plerixafor 0.12 mg/kg in Day 4. Apheresis collection was performed on Day 5. One vial of plerixafor was used for two patients. http://clinicaltrials.gov NCT03244930. RESULTS Cell mobilization and collection was successful in 85% of patients (≥2 × 106 CD34+ cells per kilogram). The median collected CD34+ cell count was 4.62 × 106/kg (range, 1.27‐24.5). A 4.1‐fold‐increase in the median CD34+ PBSC pre‐count was observed (from 10.4/μl to 42.4/μl) after RD‐plerixafor administration. Seven patients had mild to moderate adverse events. CONCLUSION RD‐plerixafor is an effective, safe, and affordable strategy to ensure adequate PBSC mobilization in patients with MM or lymphoma who undergo ASCT.

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tifactorial interference with donor T-cell maturation. Theoretically TCR GD rearrangement occurs earlier in T-cell maturation than that of TCR alpha-beta, making the GD population sensitive to early post-HSCT changes in immune homeostasis. Factors affecting the maturation and immunoregulatory properties of GD T-cells require further investigation, as does the prognostic role of TCR GD diversity in aGVHD.

Treatment with IMiDs and/or PI pre-transplant was associated with better survival versus no prior exposure to these agents but this was not statistically significant (P = .11) (Figure 2). In this analysis, we show that a significant number of patients undergo delayed ASCT for MM. Outcomes of ASCT after L1 and L2 were similar. This being a retrospective study, we cannot asses the number of patients who intended to but were not able to undergo delayed ASCT. Exposure to one or both highly active anti-myeloma agents (IMids and PI) before ASCT was associated with better post transplant outcomes.

Thrombotic thombocytopenic purpura (TTP) is characterized by a reduction in the von Willebrand cleavage protein ADAMTS-13, caused mainly by autoimmunity. Plasmapheresis is the standard of care achieving complete remission (CR) in 77-83% of cases but figures are variable depending on clinical context and ADAMTS-13 activity. Relapse is frequent in patients with <10% ADAMTS-13, and has been reported in 34-41% of cases. In most of these patients, an inhibitor against ADAMS-13 is detected thus, an effective frontline immunosuppressive treatment is needed to prevent relapses. Originally rituximab was used as a 2nd line therapy in patients with relapsed and refractory TTP aiding to achieve CR and to reduce relapse rates. The assumption that B cell population may be smaller in patients with autoimmune diseases than in neoplasia supported low-dose rituximab use and therefore, we administered plasmapheresis and low-dose rituximab as frontline therapy in 11 patients with a first TTP episode. Newly diagnosed TTP Patients >15 years received plasmapheresis with 1-2 exchanges daily until CR and rituximab 100 mg/dose/week for 4 consecutive weeks, starting the 1st dose immediately after the 2nd or 3rd plasma exchange. Relapse was defined as readmission with thrombocytopenia (< 100 × 109/L), schistocytes in peripheral blood, and ADAMTS-13 <10% after discharge. Between March 2011-March 2015, eleven patients were included; three men (27%) and eight women (73%), median age was 34 years (15-46). The median follow-up is 22 months (range 4-49) and for patients evaluable for ADAMTS-13 activity (n=8) 18 months (range 4-34). Two patients had seizures and mucocutaneous bleeding, 7 numbness, confusion and petechiae and 2 severe headache. Only 2 patients had renal damage at diagnosis (creatinine>1.2). Five patients had additional comorbidities (two diabetes mellitus, two HIV positive and one hypothyroidism) Median laboratory parameters at diagnosis: platelets 11 X 10⁹/L (range 7-27.4 X 10⁹/L), LDH 1822 U/L (range 705-8220 U/L, normal 70-180 U/L), hemoglobin 6 g/dL (range 4.2-11.8 g/dL). ADAMTS-13 activity was determined in 8 patients at diagnosis and in all of them was <10% (normal 40-130%). ADAMTS-13 autoantibody titer was determined in 7 patients and in all of them was >18 units/ml (ref: negative <12, undetermined 12-15, positive > 15 units/ml), shigella toxin was negative in all patients. The median number of plasmapheresis exchanges until CR was 7 (range 4-12)andprednisone at 1 mg/kg was administered to 6 patients. The estimated two-year relapse-free survival was 90%. One HIV+ patient suffered a relapse at 8 months follow-up. A high antibody titer against ADAMTS-13 was detected at relapse with no ADAMTS-13 activity and the patient was retreated with plasmapheresis (3 exchanges) and low-dose rituximab as described and has been in CR for 4 months. There were no complications related to plasmapheresis or rituximab infusion. According to our results low-dose rituximab and plasma exchange are effective in achieving rapid and sustained response in TTP. Of note, the median of plasmapheresis needed to CR (7, range 4-12) was lower than that reported for patients with <10% ADAMTS-13 activity (19 procedures) (Kremer Hovinga JA et al Blood 2010). In our series, median follow-up for patients evaluable for severe ADAMTS-13 deficiency was 18 months, and only one HIV-positive patient relapsed at the 8th month. Our study suggest that frontline low-dose rituximab and plasmapheresis are effective as frontline treatment for TTP. This combination is associated with relatively rapid response and low relapse rate in previously untreated patients, however, a prospective clinical trial is needed to effectively demonstrate if rituximab 100 mg x 4 weekly dose is as effective as the conventional 375 mg/m2 X 4 weekly dose. Disclosures Off Label Use: Rituximab an anti CD monoclonal antibody is used in our work to deplete B cell population therefore stop the production of autoatibodies against ADAMTS-13.

plete blood counts 10 months after the procedure. To the best of our knowledge this is the first report of a pair of monocygotic twins with concordant AML treated sequentially with an HLA-identical sibling donor graft procured in a single apheresis procedure and performed in an outpatient setting.