Reticuloendothelial function in human renal allograft recipients.

The phagocytic and metabolic functions of the reticuloendothelial system (RES) were determined, by measuring the plasma clearance rate of 125I-labelled microaggregated human serum albumin and the increase in plasma metabolites of this test substance, in patients with chronic renal failure and in renal transplant recipients at different times after transplantation. All transplant recipients received triple immunosuppressive therapy consisting of azathioprine, corticosteroids, and antilymphocyte globulin. The intravascular clearance of microaggregated albumin was significantly depressed in patients when tested at 1 to 12 days (P less than 0.001), 1 to 4 months (P less than 0.02), and 6 to 9 months (P less than 0.001) after transplantation compared to pretransplantation. The 1- to 3-year transplant survivors had a normal RES phagocytosis. Furthermore, the metabolic RES function in all groups of transplant recipients except the group of patients tested at 1 to 4 months after transplantation was significantly impaired compared to pretransplantation. Administration of antilymphocyte globulin and extremely high daily doses of steroids were probably responsible for the significant depression in the RES functions recorded immediately post-transplantation. The further development of the phagocytic ability of the RES was shown to be correlated to the cumulative dose of steroids given over the last 12 months. The azathioprine regime seemed to have no influence on the RES functions.

The effect of immunosuppressive therapy on the phagocytic and metabolic functions of the reticuloendothelial system in renal transplant recipients.

The object of this study was to examine the bearing that immunosuppressive therapy may have on the phagocytic and metabolic functions of the reticuloendothelial system (RES). The phagocytic and metabolic activities of the RES were determined in renal graft recipients before transplantation and at intervals afterwards. The activities were measured as the plasma clearance rate of 125I-labelled microaggregated human serum albumin and the increase in the plasma metabolites of this test substance. The intravascular clearance of microaggregated albumin was significantly depressed at 1-12 days (P less than 0.001), 1.4 months (P less than 0.02) and 6-9 months (P less than 0.01) after transplantation compared to the levels before operation. RES phagocytosis was normal in the 1-3 year group. Furthermore, in all except the 1-4 month group the metabolic activity was significantly reduced. The significant impairment of the RES functions immediately after transplantation was probably due to administration of antilymphocyte globulin and extremely high doses of steroids. After antilymphocyte globulin had been withdrawn the phagocytic capacity of the RES was correlated to the total dose of steroids given over the 12 months prior to the test. The azathioprine regime seems to have had no influence on the RES functions.

Renal transplant wound infection: the value of prophylactic antibiotic treatment.

The incidence of wound infection after 310 renal transplant operations was examined. Among the 78 recipients not given prophylactic antibiotic therapy infection of the transplant wound occurred in 25.6%. Among the 232 patients given prophylactic therapy, with narrow-spectrum antibiotic (cloxacillin), wound infection occurred in only 7.8%. This statistically significant difference in incidence was ascribed to a less frequent occurrence of staphylococcal wound infection in the group of patients receiving antibiotic therapy than in the group not so treated. The presence of wound haematoma, which increased the risk of wound infection, was the only factor predisposing to such infection in this patient series.

Bacteremia in a Swedish university hospital: a one-year prospective study in 1981 and a comparison with 1975-76.

A one-year prospective study of bacteremia was carried out at a Swedish university hospital. Blood cultures were taken in 6.3% of all patients admitted to the hospital. 148 episodes of bacteremia were recorded in 142 patients, 59% of whom were males. The mean incidence of bacteremia was 4.3 episodes per 1,000 admissions. The incidence of contamination was 1.3%. Malignancy and urinary tract disorders were the most common diagnoses and surgical intervention, central venous catheters and cytostatic drugs the most common predisposing factors. The ratio of hospital to community-acquired bacteremia was 1.3:1. The fatality rate was 12.7%. Gram-negative rods belonging to the Enterobacteriaceae were the most common pathogens, followed by Staphylococcus aureus and Staphylococcus epidermidis. The antibiotic sensitivity pattern of the causative bacteria was quite favorable. No S. aureus strains were resistant to isoxazolyl penicillins or gentamicin. No Klebsiella strain and only one Escherichia coli strain was resistant to gentamicin. The results were compared to a one-year retrospective study carried out in the same hospital five years ago. The incidence of bacteremia had not increased between the two studies.

Studies of cytomegalovirus infection in renal allograft recipients.

A prospective study of cytomegalovirus (CMV) infections has been carried out in 28 renal graft recipients. The protocol called for frequent blood and urine sampling during the first year after transplantation, but death or graft loss caused earlier termination in nearly half the patients. In this material 5/7 (71%) susceptible patients developed primary infections and 20/21 experienced a secondary infection (95%). Viruria was detected in 79% and viremia in 43%. The type of blood cell responsible for the viremic phase was studied by separating the blood cells on a density gradient. The polymorphonuclear cell fraction was the most common source of virus but virus could also be recovered from the mononuclear cell fraction. As some samples that were freeze-thawed repeatedly never yielded virus, it would appear that viable cells are needed for virus isolation. In both primary and secondary infections isolation of CMV from blood cells often preceded the isolation of CMV from urine. Among variables tested for a possible relationship to the occurrence of CMV viremia the only one to display such an association was the time at which rejection episodes occurred. In 19/28 such episodes recorded in 19 patients there was a temporal relationship to viremia (p less than 0.03). Seven of the patients experienced clinical symptoms suggestive of CMV infection as fever, cough, myalgia, arthralgia, chest pain and pneumonia. Laboratory signs included elevated amino acid transferase levels, leukopenia and thrombocytopenia and a specific anti-CMV antibody response.

Studies of cytomegalovirus infection in renal allograft recipients. II. Serological response to various viral antigens.

In a prospective study the antibody response to various cytomegalovirus (CMV) antigens was examined in 28 renal allograft recipients. Both primary and secondary infections were investigated. Antibodies against immediate early (IEA) and early antigens (EA) were studied by anti-complement immunofluorescence; IgM and IgG antibodies to nuclear late antigens were differentiated by enzyme-linked immunosorbent assay (ELISA). The results of the tests were compared with each other and with those of the complement fixation (CF) test. 5/7 susceptible patients (71%) contracted primary infections. Both IgM and IgG antibodies developed and antibodies to IEA and EA appeared somewhat later. The antibodies to IEA and EA remained detectable throughout the observation period. Secondary infections developed in 20/21 (95%) patients. All initially had CMV antibody levels in ELISA and CF. Rising CMV titers of IgG antibodies were taken as a measure of secondary infection. IgM antibodies developed in only 10/20 (50%) patients. The highest titers of CMV IgM antibody levels were lower in secondary than in primary infections. Antibodies to IEA and EA were present prior to transplantation in some patients, but did not develop in all with secondary infections. The antibody titers were lower just after than before the transplantation in some patients. but subsequently increased again. It thus seems as if the humoral immune response to these CMV antigens differs in primary and secondary infections.