Search PubMed⌕ Search

Biomedical subjects

M Kreisler

Publications and source records attributed to M Kreisler.

57 records · Page 4Linked to original sources

[Inhibition of expontaneous cytotoxicity and antibody dependency by rheumatoid synovial fluid].

A number of authors have pointed out a diminution of ADCC (Antibody dependent cellular cytotoxicity) in lymphocytes from peripheral blood of patients with rheumatoid arthritis (RA). It has also been found that the addition of rheumatoid serum inhibits ADCC and also spontaneous cellular cytotoxicity (SCC). This effect could be the result of blocking of effector cell receptors for the Fc fragment of IgG by anti-immunoglobulins and/or immune complexes, present in great quantities in rheumatoid serum. We investigated the effect of synovial fluid on the ADCC and SCC shown by purified suspensions of lymphocytes from healthy donors and RA patients towards chicken erythrocytes tagged with 51 Cr. The samples of synovial fluid from patients with RA or arthrosis did not influence per se the spontaneous release of 51 Cr, once their complement had been removed. Seven-eight of the rheumatoid synovial fluid (RSF) produced a significant decline (p less than 0.01) of SCC. Lymphocytes from the peripheral blood of RA patients showed a greater decline in SCC after the addition of RSF than those from healthy subjects (p less than 0.02). In 14/16 RSF and 5/7 samples of arthrosis synovial fluid (ASF) the ability to diminish ADCC significantly (P less than 0.01) was shown. RSF maintained this inhibitory effect in 1:40 and 1:80 dilutions, whereas in these conditions ASF had no effect on ADCC. RSF and ASF, before their complement was removed, showed an opposite effect, provoking an increase in cytotoxic activity, both SCC and ADCC, though in different proportions. These experiments show that RSF, like rheumatoid serum, inhibits ADCC and SCC, possibly by the same mechanism which blocks the Fc receptors by means of immune complexes, and coincides in its general lines with the recent findings of Díaz Jouanen et al. The pathogenetic implications of this phenomenon are difficult to clarify at present. Its occurrence in vivo would represent the establishment of a local block of cytotoxic effector cells (protector effect), which, on the other hand, would no longer be able to exercise their destructive action against cells responsible for the initiation and/or maintenance of articular damage (pathogenic effect). The non-participation of T cells, in these types of cytotoxicity, previously shown by other authors, accentuates the importance of thymus-independent regulatory systems in the mechanisms which maintain articular damage in RA.

Antibody-Dependent Cell Cytotoxicity↗

Efficacy of low-dose OKT3 as cytolytic induction therapy in heart transplantation.

BACKGROUND: The need for prophylactic cytolytic treatment in heart transplantation is a controversial issue. Its use, however, might prevent the onset of cellular rejection in the immediate postoperative period, facilitating patient management. It has recently been suggested that the administration of these products at low doses might have the same immunologic impact and would reduce secondary effects and the cost of treatment. METHODS: In a nonrandomized retrospective study, we assessed 45 consecutive patients who underwent orthotopic heart transplantation in 1992 and 1993. Six patients who died before receiving the complete OKT3 dose were excluded. Twenty-three patients were treated with 5mg/day doses of OKT3 for 7 consecutive days. Another 16 patients received 2.5 mg of OKT3 for 7 consecutive days. RESULTS: There were no significant differences between the two groups with respect to CD3 counts on days 2 (0.1% +/- 0.3% versus 0.04% +/- 0.25%; p > 0.05) and 6 (0.2% +/- 0.45% versus 0.1% +/- 0.3%; p > 0.05), number of rejection episodes (1.45% +/- 0.8% per year of follow-up versus 1.7% +/- 1.2%, p = 0.66), number of infectious complications (8 versus 3, p > 0.05), total methylprednisolone dose used to treat rejection crises (3900 +/- 2765 versus 3600 +/- 1963 mg; p = 0.71), adverse effects attributed to OKT3 (two versus none), or length of the postoperative hospital stay (36.8 +/- 19 versus 30.2 +/- 20.9 days). CONCLUSIONS: As cytolytic induction therapy in heart transplantation, a daily regimen of 2.5 mg of OKT3 for 7 days achieves the same clinical and immunologic effect as the conventional 5 mg/day dose. In addition, it results in a considerable reduction in the cost of treatment.

Azathioprine↗