Blood group incompatibility between donor and recipient of allogeneic stem cell transplants may be associated with post-transplant erythroid aplasia. A total of 548 patients (pts) received allogeneic transplant for malignant and non-malignant hematologic disorders. In a retrospective analysis, the prevalence and outcome of pure red-cell aplasia (PRCA) in 44 pts with major and bi-directional ABO-mismatch were investigated. Bone marrow grafts were major ABO incompatible in 30 pts; there was bi-directional mismatch in the remaining 14 pts. The median number of transplanted mononuclear cells (NC) was 4.74 x 10(8)/kg (range 0.1-26.4) including CD34+ cells, 3.02 x 10(6)/kg (range 0.9-21.7). Granulocyte engraftment >0.5 x 10e9/l occurred after a median of 21 days (7-32), and platelet exceeded >50 x 10e9/l after a median of 23.5 days (12-109). Acute and chronic graft vs host disease (GVHD) developed in 23 (52%) and 26 (59%) of the patients, respectively. Six (13%) patients transplanted with major and bi-directional ABO-incompatibility developed PRCA. The treatment of PRCA consisted of plasmapheresis (PEX), rapid cyclosporine (CsA) discontinuation, donor lymphocyte infusions (DLI), erythropoietin (EPO), azathioprine, and rituximab. The therapy resulted in erythroid recovery in five out of six patients after a median of 13 months (range 3-16). The median number of transfused red blood cells (RBCs) was 36 U (range 8-57). With a median follow-up of 37 months, the 5-year probability of overall survival (OS) for the PRCA group was 66%. Major ABO mismatch may lead to delayed donor erythroid engraftment. It results in long-term transfusion dependence and, therefore, the risk of iron overload. The therapy is long lasting, but usually effective in majority of patients.

A small subgroup of patients with hypereosinophilic syndrome (HES) demonstrates imatinib-sensitive fusion transcript-the FIP1L1-PDGFRA (F/P+). These cases are currently diagnosed as chronic eosinophilic leukaemia (CEL). In this paper, we screened 77 patients to estimate the frequency of FIP1L1-PDGFRA transcript among patients with unexplained, long-term hypereosinophilia exceeding 1.5 x 10(9)/L and to analyse the clinical and serological features in F/P+ CEL population. The FIP1L1-PDGFRA chimeric protein was detectable in 16 (14 males and 2 females) out of 77 examined HES patients (20%) by RT-PCR. Two patients suffered from cough at diagnosis. Three out of 16 (18%) patients had no organ involvements, in 5-one organ was affected and in the remaining eight cases-at least two. Eosinophilic organ damage/dysfunction identified splenomegaly in the majority of studied patients. We compared clinical and serological features between CEL F/P+ (n = 16) and HES (n = 61) patients. F/P+ cases had significantly increased WBC and absolute eosinophil count (AEC) at diagnosis (p = 0.008 and 0.02), whereas platelet count was decreased in this population (p = 0.03). Serum B12 and tryptase levels were increased (p = 0.002 and 0.004) in CEL F/P+ patients when compared to HES cases whereas serum IL-5 levels were significantly increased in the latter group (p = 0.01). Male gender and splenomegaly occurred more frequent in CEL F/P+ population (p = 0.002 and 0.0007, respectively). Additionally, patients with F/P+ CEL (n = 16) were compared with F/P- CEL (n = 8). The latter group, was significantly older, had lower AEC and higher platelet count. In conclusion, significant clinical symptoms are infrequent present and splenomegaly remains the most common organ involvement in patients with CEL expressing F/P fusion transcript. Our study confirmed the long-term remission on imatinib in this patient population.

Sixty-four untreated adult acute lymphoblastic leukemia (ALL) patients were randomized to receive chemotherapy alone, n = 31 or chemotherapy and granulocyte colony stimulating factor (G-CSF), n = 33. During induction patients received G-CSF for 5 days between four weekly Epirubicin+Vcr administrations, starting 36 h after each application and finishing 48 h before the next one with the intention to possibly generate a cell cycle dependent protection of normal hematopoietic progenitors and to stimulate granulopoiesis. The complete remission (CR) rate equaled 94% in the G-CSF group and 87% in controls. Patients who received G-CSF, if compared to the controls, had shorter granulocytopenia during induction and consolidation, displayed a lower infection rate, completed the induction-consolidation quicker and stayed shorter in hospital during induction, p < 0.001-0.04. Follow-up at 2 years revealed a rather higher probability of survival (59 vs. 27%, p = 0.04) and a lower relapse rate (32 vs. 60%) in G-CSF arm than in controls. The beneficial influence of G-CSF administered in time-sequenced fashion on survival needs further confirmation.

The prognostic value of cell differentiation antigens detected with the monoclonal antibodies of VI series was studied in 242 cases of acute nonlymphoblastic leukemia (ANLL) treated in 7 cooperating centers. A significantly higher complete remission rate was observed in patients with a higher expression of CD-15 antigen detected by VIM-D5 antibody than in those with lower values. These significant differences were proved when comparing subgroups with VIM-D5 positivity of blastic cells < 15 and > 15% (p < 0.01) as well as in the subgroups with values < 50% (median value) and ≥ 50% (p < 0.02). Our studies suggest the VIM-D5 positivity of ANLL cells to be favourable prognostic factor predicting the ability to achieve complete remission. Further studies are needed to establish whether the expression of the VIM-D5-defined antigen may serve as a prognostic factor related to survival.

Proposals and rationale for revision of the World Health Organization diagnostic criteria for polycythemia vera, essential thrombocythemia, and primary myelofibrosis: recommendations from an ad hoc international expert panel.