Apoenzyme content of serum aminotransferases in patients with a renal allograft treated with cyclosporine A and azathioprine.

In 16 patients with a renal allograft the activity concentrations of aspartate aminotransferase and alanine aminotransferase and the percentage stimulation of both enzymes were investigated. After the transplantation the patients received prednisone and cyclosporine A as immunosuppressive therapy, while exactly 3 months after the date of transplantation prednisone and azathioprine were given as immunosuppressives. In the first period, the percentage increase of the activity concentration of aspartate aminotransferase and alanine aminotransferase upon supplementation of pyridoxal-5'-phosphate in vitro were similar to that of healthy individuals. In the second period, however, the percentage increase of the activity concentration of alanine aminotransferase was much higher than that of aspartate aminotransferase. Cyclosporine A given during a period of about 400 days did not influence the percentage increase of both enzymes. It is concluded that the high stimulation of alanine aminotransferase in the second period depends on the presence of azathioprine or its metabolites in serum.

Relationship between plasma pyridoxal-5'-phosphate concentration and the apoenzyme content of serum aminotransferases in patients with a renal allograft.

In 76 patients with a renal allograft the plasma concentration of pyridoxal-5'-phosphate, the activity concentrations of aspartate aminotransferase and alanine aminotransferase and the percentage stimulation of both enzymes have been investigated. Generally, the concentration of the coenzyme was decreased in the patient group compared to normal individuals. The percentage increase of aspartate aminotransferase is the same for the patients as for the normal group. However, the stimulation of alanine aminotransferase is greatly increased for the patient group except for those patients who received cyclosporine A instead of azathioprine. The highly significant inverse correlation between the plasma pyridoxal-5'-phosphate concentration and the percentage stimulation of the enzymatic activity of aspartate aminotransferase and alanine aminotransferase observed before for a normal group, is not present in our patient group. The percentage increase is independent on the activity concentration of the enzymes. It is concluded that the high stimulation of alanine aminotransferase depends on the administration of azathioprine.

Evidence for adsorption of heterospecific host immunoglobulin on the tegument of Schistosoma mansoni.

Mice infected with Schistosoma mansoni were immunized against human type B Rh-positive (B+) RBC, bovine serum albumin, or horseradish peroxidase. Adult parasites, recovered by perfusion, extensively washed, and incubated in their respective antigens, selectively bound to their tegumental surfaces only those antigens to which their murine host had been immunized. All controls supported the specificity of those reactions leading to the conclusion that adult S. mansoni in mice have the ability to adsorb heterospecific antibody onto their tegumental surfaces. These surface immunoglobulins were lost within 10 min when complexed with theri antigens or within 2.5 hr when incubated at 37 degrees C. Parasites that had lost their tegumental immunoglobulins regained them when incubated in normal mouse or rat anti-human type B Rh-negative (B-) RBC serum. Those parasites that had their surface immunoglobulins reconstituted with rat anti-human B- serum specifically bound human B- RBC, suggesting the possible presence of Fc receptors on adult S. mansoni.