Late marrow allograft rejection following alpha-interferon therapy for hepatitis in a patient with paroxysmal nocturnal hemoglobinuria.

We describe a case of allograft rejection that occurred 23 months after successful bone marrow transplantation for severe aplastic anemia in a patient with paroxysmal nocturnal hemoglobinuria. The allograft rejection appears to have been induced by recombinant alpha-interferon (rINF-alpha) treatment for non-A, non-B hepatitis that developed 11 months after transplantation. During the 9 months of active hepatitis, the donor graft functioned normally; however, 3 months after rINF-alpha therapy was started, pancytopenia and a chimeric hematopoietic state developed. rINF-alpha was discontinued, cyclosporin A was reintroduced, and autologous bone marrow recovery followed. rINF-alpha treatment may be detrimental to some recipients of allogeneic bone marrow transplants.

Deficit of T-cell recovery after allogeneic bone marrow transplantation in chronic myeloid leukemia patients.

The immunological reconstitution that follows bone marrow transplantation (BMT) was studied in 40 leukaemia patients: 19 with chronic myeloid leukaemia (CML), 12 with acute myeloid leukaemia (AML) and the remaining 9 with acute lymphoblastic leukaemia (ALL). The recovery of the CML group was slower than that of the ALL and AML groups. This difference was produced by the T cell compartment, as NK cell activity and B cell numbers did not differ significantly. Factors such as conditioning treatment and graft versus host disease (GVHD) prophylaxis were analysed. Our experience suggests that all leukaemia patients should not be considered as one group when analysing their immunological reconstitution, as factors related to the original disease may affect their outcome.

Study of lymphocyte populations and natural killer activity in severe aplastic anaemia.

Thirty-one patients (pts) with aplastic anaemia (AA) were studied whose probable etiology were: idiopathic (16 pts), nocturnal aroxysmal haemoglobinuria (NPH) (2 pts), benzene (4 pts), agrotoxics (5 pts), pharmaceutical drugs (2 pts) and insecticides (2 pts). A decrease in total lymphocyte counts was seen in 10 pts belonging mainly to the NPH and pharmaceutical drug groups, whereas, in the benzene group the opposite was found. B cell levels were low in 9 out of 20 pts. T cell levels varied, the majority of patients had normal levels, 13 presented low levels and 4 had increased numbers. CD4 levels were low in 14 pts and T cell numbers were compensated in some by an increase in CD8 cells. Our results show that there is a great heterogeneity among the patients and there might be differences in the immunological profile of aplastic anaemia depending on the causative agent of the disease.

Immunological recovery after bone marrow transplantation for severe aplastic anaemia: a Brazilian experience.

Twenty-nine patients with severe aplastic anaemia (SAA) were submitted to bone marrow transplantation (BMT) and their immunological recovery analysed. Total lymphocyte counts, estimation of B lymphocytes, T lymphocytes and their subsets, natural-killer (NK) activity were performed. Cells with the CD8+ phenotype and NK activity were the first signs of immunological recovery, whereas the CD4+ subset recovered later in patients who suffered from acute graft versus host disease (GvHD) and infections. Acute and chronic GvHD, cirrhosis, rejection and HIV viral infection contributed to the persistence of the profound immunodeficiency status observed after BMT. Our results did not differ greatly from the others and confirmed that BMT may be performed in underdeveloped countries despite the difficulties it might pose.