Transplant-associated thrombotic microangiopathy: Incidence, prognostic factors, morbidity, and mortality in allogeneic hematopoietic cell transplantation.

Renewed interest has emerged in transplant-associated thrombotic microangiopathy (TA-TMA) with novel prognostic, diagnostic, and treatment algorithms. We aimed to investigate the incidence, prognostic factors, morbidity, and mortality of TA-TMA in allogeneic hematopoietic cell transplantation (HCT) recipients. We enrolled consecutive HCT recipients (1990-2017). Among 758 patients, 116 (15.5%) were diagnosed with TA-TMA. In the multivariate analysis, TBI-based conditioning, viral infections, acute and chronic GVHD remained independent predictors of TA-TMA. With a median follow-up of 23 (range 0.1-329) months, TA-TMA resulted in significantly lower overall survival (OS). In the multivariate analysis, TA-TMA remained an independent predictor of OS, along with relapse, acute, and chronic GVHD. Among 116 TA-TMA patients, 70 developed renal (56) and/or neurologic (26) dysfunction that would be necessary for TA-TMA diagnosis according to the Bone Marrow Transplant Clinical Trials Network criteria. TA-TMA patients with renal dysfunction showed increased rates of acute GVHD, but no difference in OS compared to patients without renal dysfunction. However, neurologic dysfunction resulted in significantly lower OS. In conclusion, TA-TMA is associated with increased morbidity and mortality in allogeneic transplant recipients. Successful prevention and treatment strategies of infections and GVHD need to be timely employed to improve survival in this complex setting.

Intestinal thrombotic microangiopathy: a distinct entity in the spectrum of graft-versus-host disease.

Transplant-associated thrombotic microangiopathy (TA-TMA) is a severe complication of allogeneic hematopoietic cell transplantation (allo-HCT) with multisystem involvement. Cases of TMA in the intestinal vasculature (intestinal TMA/iTMA) have been reported. We hypothesized that iTMA is a distinct entity from TA-TMA. To test this hypothesis, we prospectively recruited allo-HCT recipients with an indication for endoscopy. Among 20 patients, histological features of iTMA, including loss of glands, total denudation of mucosa, apoptosis and detachment of endothelial cells, mucosal hemorrhage, intraluminal fibrin and microthrombi were found in six. Only 2/6 were classified as GVHD/TA-TMA, while the other 4 as GVHD/no TA-TMA. Gastro-intestinal symptoms were similar between the patients with or without iTMA. With a median follow-up of 11.1 (2.1-67.5) months, 1-year overall survival was 22.2% for iTMA, 55% for GVHD and 60% for TA-TMA. On multivariate analysis, independent unfavorable predictors of OS were iTMA (p = 0.048), HLA mismatched donors (p = 0.008) and gastro-intestinal bleeding (p = 0.021). In conclusion, iTMA emerges as a novel distinct entity in patients with GVHD and/or TA-TMA. Distinct histological features may be useful in differential diagnosis of these severe HCT complications. The higher mortality rates of iTMA than TA-TMA highlight the need for further investigation of this condition.

The Role of Low-dose Anti-thymocyte Globulin as Standard Prophylaxis in Mismatched and Matched Unrelated Hematopoietic Peripheral Stem Cell Transplantation for Hematologic Malignancies.

INTRODUCTION: Anti-thymocyte globulin (ATG)-based immunosuppressive therapy is often used in allogeneic hematopoietic cell transplantation to reduce incidence and severity of graft-versus-host disease (GVHD). PATIENTS AND METHODS: In our observational study, ATG (rabbit, Thymoglobulin; Sanofi, 5 mg/kg) was administered as a standardized part of the conditioning in 97 patients with a median age of 34 years (range, 14-58 years), allotransplanted for hematologic malignancies from matched (8/8; n = 52) and allele or antigen mismatched (7/8; n = 43 and 6/8; n = 2) unrelated donors. RESULTS: Five-year overall survival (OS) was 46.9%, disease-free survival was 46.5%, and treatment-related mortality was 20.6%, with a median follow-up of 29 months (range, 1-145 months). Acute GVHD (grade ≥ II) cumulative incidence was 26.9% in matched versus 50.5% in mismatched patients (P = .060), whereas extensive chronic GVHD was 45.6% versus 50%, respectively (P = .310). Five-year OS was 62.2% for the matched patients and 27.9% for the mismatched patients (P = .003) owing to a higher treatment-related mortality rate in mismatched patients (P = .032). In multivariate analysis including age, gender, time until transplantation, disease phase, mismatched donor, ABO mismatch, number of CD34+ infused, acute and chronic GVHD, the significant unfavorable factors for OS were HLA mismatch and advanced disease phase. CONCLUSION: A relatively low-dose ATG is effective in acute GVHD prophylaxis, leading to promising survival rates in matched transplants. Further comparative studies with adjusted ATG dose depending on Human leukocyte antigen disparity or alternative donors are warranted.

Transferrin receptor-1 and 2 expression in chronic lymphocytic leukemia.

Transferrin receptor (TfR)-1 and 2 mRNA and CD71 (TfR1) expression was analyzed in 118 CLL patients. Ninety-five out of 109 analyzed cases expressed CD71, mostly at a high level; 60% of CD71 (+) cases were IGH-mutated. All samples were TfR1 mRNA (+); TfR2-alpha/beta mRNA was detected in, respectively, 52/102 and 100/109 cases. Competitive RT-PCR showed widely divergent levels of TfR1 mRNA in cases with high CD71 expression, alluding to post-transcriptional control of TfR1 expression in CLL. The almost uniformly high CD71 expression in CLL is in keeping with the activated status of neoplastic cells, regardless of IGH mutational load.

Clinical, immunophenotypic, and molecular profiling of trisomy 12 in chronic lymphocytic leukemia and comparison with other karyotypic subgroups defined by cytogenetic analysis.

In a cohort of 130 unselected chronic lymphocytic leukemia (CLL) patients, 73 cases had normal karyotypes, 57 cases had abnormal karyotypes, and 22/57 cases carried more than one abnormality. Trisomy 12 (+12) was the most common abnormality (26/130 cases; 20%), and 17/26 cases had isolated +12. Del(13q)/t13q/-13 was detected in 19/130 cases (14.6%), and 5/19 cases had isolated del(13)(q12q14). Deletion (11)(q23) and del(17p)/-17 were detected in 5/130 cases, respectively. CD38 expression was significantly more frequent in the +12/11q/17p versus the normal/del(13q) subgroups. A significant association was detected between +12 and FMC7 positivity. IGHV-unmutated cases were significantly more frequent in the +12/11q/17p subgroups. Patients with normal karyotype/del(13q) had a longer median time to progression versus the patients in the +12/11q/17p subgroups. According to multivariate analysis, only IGHV mutation status remained a statistically significant variable for progression-free survival (PFS). Furthermore, IGHV mutation status and clinical stage at diagnosis were the only significant prognostic factors for overall survival. Among Binet-A patients, significant parameters for shorter PFS were +12 or 11q/17p aberrations, CD38 expression, and IGHV unmutated status. In multivariate analysis, only CD38 expression and IGHV-unmutated status retained statistical significance for PFS. In conclusion, trisomy 12 in CLL is characterized by considerable heterogeneity and seems to be associated with disease progression.

Molecular evidence for transferrin receptor 2 expression in all FAB subtypes of acute myeloid leukemia.

We examined transferrin receptor (TfR) 1 and TfR2 mRNA expression in 50 acute myeloid leukemia (AML) patients by RT-PCR, with primers specific for exons 15-17 (TfR1), 3-5 (TfR2-alpha) and 4-5 (TfR2-beta) of the corresponding gene. There were 4/50 TfR1-negative (-), 3/50 TfR2-alpha mRNA (-) and 13/50 TfR2-beta mRNA (-) cases; only three cases were TfR1/2 mRNA (-). No significant correlations were identified between TfR2-beta mRNA negativity and specific FAB subtypes, karyotype or attainment of complete remission. These findings suggest that: (i) TfR2 expression is not restricted to erythroid cells, and (ii) iron import proteins might complement each other in AML cells.

Feasibility of an easily applicable method of ZAP-70 measurement in chronic lymphocytic leukemia in the routine flow cytometry setting: A methodological approach.

Zeta-associated protein 70 (ZAP-70), determined by flow cytometry, has been advocated a surrogate marker of immunoglobulin (Ig)V(H) unmutated status in B chronic lymphocytic leukemia (CLL). The aim of the current study was to test the applicability of an easy flow cytometry protocol for ZAP-70 measurement in CLL samples. Samples from 61 CLL patients and 44 normal subjects were analyzed using a commercial ZAP-70 monoclonal antibody (1E7.2 clone) conjugated with phycoerythrin (PE) and Alexa 488 fluorochromes. Modifications of the published methods led to the structure of a simplified in-house method of ZAP-70 measurement. A three-color approach was used with CD19, CD3 gating comparing with the isotype control provided by the same manufacturer. The cutoff levels for ZAP-70 positivity were defined from a receiver operator characteristic curve in relation to the IgV(H) mutational status and from the ln normalized mean value +2 SD of normal controls. Using the 20% cutoff value for ZAP-70 positivity in CLL patients defined by the literature, ZAP-PE had a sensitivity of 55% and a specificity of 98% in predicting the IgV(H) mutational status, whereas the corresponding values for ZAP-Alexa were 55% and 84%, respectively. Using the 7% cutoff value for CD38 positivity, the sensitivity was 55%, whereas the specificity was 76%. ZAP-70-positive patients showed a shorter time to disease progression in comparison with ZAP-70-negative patients (p < 0.001). In conclusion, the 100% specific prediction of mutational status is accompanied by reduced sensitivity, thus limiting ZAP-70's applicability either as a single marker or combined with CD38 for the assessment of the mutational status of CLL.

Immunoglobulin light chain repertoire in chronic lymphocytic leukemia.

Immunoglobulin kappa (IGK) and immunoglobulin lambda (IGL) light chain repertoire was analyzed in 276 chronic lymphocytic leukemia (CLL) cases and compared with the relevant repertoires from normal, autoreactive, and neoplastic cells. Twenty-one functional IGKV genes were used in IGKV-J rearrangements of 179 kappa-CLL cases; the most frequent genes were IGKV3-20(A27), IGKV1-39/1D-39(O2/O12), IGKV1-5(L12), IGKV4-1(B3), and IGKV2-30(A17); 90 (50.3%) of 179 IGK sequences were mutated (similarity < 98%). Twenty functional IGLV genes were used in IGLV-J rearrangements of 97 lambda-CLL cases; the most frequent genes were IGLV3-21(VL2-14), IGLV2-8(VL1-2), and IGLV2-14(VL1-4); 44 of 97 IGL sequences (45.4%) were mutated. Subsets with "CLL-biased" homologous complementarity-determining region 3 (CDR3) were identified: (1) IGKV2-30-IGKJ2, 7 sequences with homologous kappa CDR3 (KCDR3), 5 of 7 associated with homologous IGHV4-34 heavy chains; (2) IGKV1-39/1D-39-IGKJ1/4, 4 unmutated sequences with homologous KCDR3, 2 of 4 associated with homologous IGHV4-39 heavy chains; (3) IGKV1-5-IGKJ1/3, 4 sequences with homologous KCDR3, 2 of 4 associated with unmutated nonhomologous IGHV4-39 heavy chains; (4) IGLV1-44-IGLJ2/3, 2 sequences with homologous lambda CDR3 (LCDR3), associated with homologous IGHV4-b heavy chains; and (5) IGLV3-21-IGLJ2/3, 9 sequences with homologous LCDR3, 3 of 9 associated with homologous IGHV3-21 heavy chains. The existence of subsets that comprise given IGKV-J/IGLV-J domains associated with IGHV-D-J domains that display homologous CDR3 provides further evidence for the role of antigen in CLL pathogenesis.

Rituximab is effective for selected patients with chronic steroid-refractory immune thrombocytopenic purpura.

We report results of Rituximab therapy in four patients with chronic immune thrombocytopenic purpura (ITP) refractory to 3-8 prior therapeutic regimens. Rituximab was administered at a dose of 375 mg/m2 once weekly for 4-6 weeks. Three out of four patients achieved a complete remission (rise to platelet count above 100,000/microl). Response duration was 4, 16+, and 11+ months. Rituximab was well tolerated but one patient (a 77 year-old male) developed two serious infections, pneumonia and a hepatic abscess, at 2 and 4 months. We conclude that Rituximab is effective in patients with refractory ITP; nevertheless, careful patient selection is mandatory.