Efficacy of single dose pegfilgrastim in enhancing the mobilization of CD34+ peripheral blood stem cells in aggressive lymphoma patients treated with cisplatin-aracytin-containing regimens.

Systematic data on the ability of pegfilgrastim to mobilize stem cells after chemotherapy are scarce. We evaluated the efficacy of a single 6 mg dose of pegfilgrastim for mobilizing peripheral blood stem cells (PBSC) in aggressive lymphoma patients. Between July 2004 and October 2005, 17 aggressive non-Hodgkin's lymphoma and 11 poor-risk Hodgkin's lymphoma were treated with cycles containing cisplatin-aracytin. At the end of chemotherapy, the patients received 6 mg of pegfilgrastim. Duration of grade 4 neutropenia, adverse events, time to neutrophil recovery, peak and harvest of CD34+ cells were recorded. Twenty-seven out of 28 patients harvested a median of 17.3 x 10(6)/CD34+ cells (range 2.5-28.9) after a median of 9 days (range 8-12 days), with a single apheresis procedure in 25 cases. All patients had grade 3-4 neutropenia, median duration 3 days. The only adverse event was mild bone pain. To date, 13 patients have been autografted with a median of 15.4 x 10(6) CD34+ pegfilgrastim-mobilized cells per kg (range 2.5-28.9) with rapid and sustained engraftment. Mobilization, harvesting and autografting of pegfilgrastim-mobilized PBC can be successfully achieved in pretreated patients with aggressive lymphoma.

Trisomy 4 leading to duplication of a mutated KIT allele in acute myeloid leukemia with mast cell involvement.

A G-->T transversion at nucleotide 2467 of the c-KIT gene leading to Asp816-->Tyr (D816Y) substitution in the phosphotransferase domain has been previously identified in a patient with rapidly progressing AML-M2 and mast cell involvement; the patient's blasts had a 47,XY, +4,t(8;21)(q22;q22) karyotype. Herein we confirm the simultaneous presence of both major chromosomal changes by multicolor fluorescence in situ hybridization (FISH) on interphase CD34+ mononuclear cells. By setting up culture leukemic blasts, spontaneous differentiation of adherent cells with mast-cell like features was proved by histochemical and immunoenzymatic analyses. Fluorescence in situ hybridization evidence of trisomy 4 confirmed the origin of differentiated cells from the leukemic blasts. Semiquantitative polymerase chain reaction (PCR) and phosphoimage densitometry of wild-type and mutated KIT alleles on bone marrow blasts made it possible to demonstrate that chromosome 4 trisomy led to a double dosage of the mutated KIT allele. This finding, and that of trisomy 7 and MET mutation in hereditary renal carcinoma represent the only cases of human tumors in which an increased number of chromosomes carrying an oncogene activated by point mutation have been detected.

The multimeric pattern of von Willebrand's factor (vWF) can be demonstrated also in the severe form of the disease.

The multimeric analysis was carried out on the plasma of 18 patients with severe von Willebrand's disease (vWD) using two different types of agarose: Seakem HGT(P) and Seaplaque LGT. No pattern was found in any of the patients using Seakem HGT(P). On the contrary, by Seaplaque LGT, a multimeric pattern was found in four patients belonging to three different families, indicating that it is possible to identify and characterize variable multimeric patterns also in type III vWD.

Prothrombin-antibody coexistent with lupus anticoagulant (LA): clinical study and immunochemical characterization.

The patient is a 23 y.o. man with acute nephritis and bleeding at presentation. Laboratory data consistent with the diagnosis of systemic lupus erythematosus. A lupus anticoagulant was found: tissue thromboplastin inhibition test (TTIT) ratio 3.4; diluted Russell viper venom (DRVV) ratio 2.6. Hypoprothrombinemia (FII:C less than 1%; FIIR:Ag 5%) was present; prothrombin survival time (FII concentrate infusion 60 U/kg): t1/2 approximately to 9 hours. A prothrombin antibody was identified: it is not neutralizing but forms an immunecomplex with prothrombin. The antibody was characterized as IgG2, IgA, k, lambda. The prothrombin survival time indicates that the hypoprothrombinemia is due to the clearance of the prothrombin-antiprothrombin complex in vivo.

Severe von Willebrand's disease: SDS agarose multimer analysis.

In severe von Willebrand's disease (vWD), the multimeric analysis of von Willebrand factor (vWF) has been hindered by the low content of the protein although different patterns have been observed by radiocrossed immunoelectrophoresis (RCIE). Cryoprecipitate and vWF concentrate were obtained from the plasma of a severe vWD patient, that on RCIE had only the more anodic forms. The sodium dodecylsulfate (SDS) agarose analysis evidences the presence of the main bands, a relative increase of the smaller forms and a lesser definition of some minor bands. These findings suggest the possibility of structural abnormalities in severe vWD. The study of cryoprecipitates could be a means to evidence the presence of multimers and the extent of the eventual pattern variability.

Acquired factor VIII:C inhibitor (IgG) and positive direct Coombs' test (IgM) in a patient with lung carcinoma. Clinical course and immunochemical studies.

UNLABELLED: A 73-year-old man with lung squamous-cell carcinoma simultaneously developed a factor VIII:C inhibitor and a transient positive direct Coombs' test. The factor VIII:C inhibitor was characterized as a mixture of IgG1, IgG2, IgG4 with kappa and lambda light chains. The Coombs' test was IgM-specific. TREATMENT: blood transfusions (packed red cells), cyclophosphamide and prednisone. Bleeding subsided without factor VIII-replacement therapy. Before death, in spite of the tumour-mass progression, factor VIII:C was normal.