Flow cytometry as a tool in the diagnosis of Bernard-Soulier syndrome in Brazilian patients.

Bernard-Soulier Syndrome (BSS) is an inherited recessive bleeding disorder. In some instances, diagnosis might be restricted to routine blood exams, including bleeding time, prothrombin time (PT), and partial thromboplastin time (APTT). Exams such as platelet aggregation, and testing for expression of ristocetin cofactor, or von Willebrand factor may not be commonly performed. This leads to misdiagnosis in a number of patients, which are subsequently treated erroneously. Flow cytometry has been used widely as a tool in the diagnosis of leukemias, lymphomas, and many other immuno-hematological diseases. The purpose of this study was to assess whether flow cytometry could be helpful in the diagnosis of Bernard-Soulier Syndrome in Brazilian patients. For this, we examined a selected group of 15 patients with suspected BSS based on classical diagnosis. We used a panel of antibodies to detect the expression of glycoproteins GPIbalpha, GPIIb, GPIIIa, GPIX, as well as CD9. Abnormalities of GPIb and GPIX were observed in nine of the 15 patients, which included severe reduction of both antigens, of one or the other, or normal levels but weak expression. Strikingly, this abnormality correlated with severely reduced expression of CD9 in all cases. We discuss the implications for flow cytometric diagnosis of BSS.

Marrow transplantation for Fanconi anaemia: conditioning with reduced doses of cyclophosphamide without radiation.

Nine patients with Fanconi anaemia (FA) were conditioned for HLA-identical sibling bone marrow transplant (BMT) with reduced dose of cyclophosphamide (Cy) without radiation or antithymocyte globulin (ATG). The total dose of Cy was 140 mg/kg (n = 2) or 120 mg/kg (n = 7). The median patient age was 8 years (range 4-19). Graft-versus-host disease (GVHD) prophylaxis was with methotrexate and cyclosporine (n = 8) or cyclosporine alone (n = 1). All patients had sustained engraftment and two developed grade>/= II acute GVHD. Cy toxicity included grade >/= 2 mucositis seen in all evaluable patients and haemorrhagic cystitis in two patients. The Kaplan-Meler survival estimate is 89% with a median follow-up of 285 d (range 56-528). For the purpose of comparison, this report also reviews and updates long-term follow-up data on 32 previously reported FA patients conditioned with 140-200 mg Cy/kg without radiation. The lowest dose of Cy (without radiation or ATG) after which HLA-identical sibling marrow transplant can be successfully performed in FA patients has yet to be determined, but it appears that uniform and sustained engraftment can be achieved with a Cy dose of as low as 120 mg/kg.