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Biomedical subjects

M R Raffo

Publications and source records attributed to M R Raffo.

26 records · Page 2Linked to original sources

T cell subpopulations after allogeneic bone marrow transplantation.

T-cell subpopulations were studied in six patients after allogeneic bone marrow transplantation for aplastic anemia and acute leukaemia, by means of receptors for IgG (TG-cells) and IgM (TM-cells). Significant modifications of TM-TG levels were found: a 2 to 10 fold increase of TG cells and a 2 to 10 fold decrease of TM cells from pre-transplant levels could be observed. The TM-TG imbalance appeared together with the clinical signs of GVHD: the level of TM-depression (but not the level of TG increase) correlated with the severity of GVHD. The TM-TG modifications were observed as long as 3 years after transplantation, also in the absence of signs of GVHD. In addition, all six patients were found to have severely impaired pokeweed-induced B-cell differentiation. The clinical implications and the possible lack of T-helper activity are discussed.

Acute Disease↗

Lack of in vitro colony (CFUC) formation and myelosuppressive activity in patients with severe aplastic anemia after autologous hematologic reconstitution.

In vitro colony formation (CFUC) was studied in 8 patients with severe aplastic anemia (SAA) in complete hematologic remission following high dose pulse methylprednisolone (P/6-MPr) and/or antilymphocyte globulin (ALG). All patients except one were off maintenance treatment at the time of study, and follow-up ranged from 271 to 630 days. All patients showed marked reduction of colonies (2 +/- 3/2.5 x 10(5) cells; our normal 61 +/- 14) and clusters (77 +/- 45; our normal 179 +/- 83), which persisted for as long as 600 days after initial therapy. Incubation of patients' marrow with ALG did not enhance significantly colony formation. Co-culture of bone marrow from 6 patients with SAA in remission and normal marrow produced a marked inhibition of the expected colonies (84 +/- 16%) and clusters (29 +/- 23%). Incubation of patients' marrow with ALG prior to the co-culture experiments did not prevent suppression of colonies and clusters. Co-culture of patients' peripheral blood lymphocytes with normal marrow had no effect on colony formation. Therefore remission marrow from patients with SAA exhibits severely impaired in vitro growth (CFUC) and marked myelosuppressive activity against normal marrow cells. Incubation of patients' marrow with ALG has no significant effect on either assay.

Anemia, Aplastic↗

Bone marrow transplantation for severe aplastic anemia. A report of 9 cases.

9 patients with severe aplastic anemia (SAA) were treated with bone marrow transplantation (BMT). 5 were conditioned with cyclophosphamide and received and HLA-identical graft (4 patients) or a mismatched graft (1 patient): 1 rejected the graft on day 30 and died on day 34 during conditioning for a second transplant; 1 died on day 15 with acute and severe graft versus host disease (GvHD) in the absence of haemopoietic engraftment; 3 are alive and complete chimeras at 1,069, 490 and 332 days after transplantation. GvHD developed in 4 patients and was treated successfully in 3 with high dose methylprednisolone and/or antilymphocytic globulin (ALG). 4 patients were conditioned with ALG and received bone marrow from a haploidentical sibling or parent: 1 patient was refractory; 3 patients showed evidence of hematologic reconstitution, but 2 of these required a second course of ALG. 3 patients in this group are alive between 60 and 490 days; 1 patient died on day 121 of HBSAg-negative acute hepatitis.

Adolescent↗