Pseudolymphoma in renal allograft recipients.

Five renal transplant recipients exhibited giant systemic lymphadenopathy shortly after transplantation. Biopsy specimens did not show Hodgkin's lymphoma. Immunosuppression was continued in all patients. In contrast to the rapidly fatal course of malignant lymphoma in transplant recipients, adenopathy in these five patients has uniformly resolved. Patients have been observed for 6 to 15 months with no evidence of residual disease. Interval biopsy specimens are not malignant. Each patient received antithymocyte globulin from a single lot for 10 to 21 days after transplantation. During administration, T cell lymphocytes were suppressed to 5% of control values. When lymphadenopathy occurred, T cell values rebounded to 371% of control values. Toxoplasmosis titers as well as viral cultures of lymph node biopsy specimens were negative. These data indicate a benign course of this histologically malignant disease and suggest a lymphoblastic rebound phenomenon to antithymocyte globulin.     

Ureteric obstruction in renal allograft recipients.

In 50 consecutive renal allograft recipients, operated upon between September 1975 and March 1977, we have encountered 10 cases of ureteric obstruction. The patients fell into two groups: those with ureteric obstruction of early onset due to intraluminal blood clot, oedema of the distal end of the ureter, ureteric tip necrosis or extrinsic compression by the spermatic cord, and those with obstruction of late onset due to ureteric fibrosis. Two cases of ureteric obstruction due to oedema and 1 due to intraluminal blood clot resolved spontaneously. Transurethral ureteric meatotomy, a recommended procedure for the relief of ureteric obstruction in suitable cases, was successful in 1 of our patients. The remaining 6 patients required open surgical procedures for relief of obstruction. In no instance did ureteric obstruction result in death or graft failure.     

Infective complications in renal allograft recipients.

Infective complications were analysed in 74 patients who underwent renal transplantation. Bacterial infections were seen in 69%, viral infections in 48% and fungal infections in 17% of these patients. The urinary tract was involved in 56% of patients, the lungs in 24% and the upper respiratory tract in 17%. Less common were cellulitis (7%), CNS infections (4%), and other sites of infection.     

HBs antigenemia in renal allograft recipients.

Serial HBs Ag determinations were performed on 98 renal allograft recipients with functioning grafts for 6 to 108 months, 85 of whom were followed from the initiation of dialysis. Twenty-six (27%) recipients had HBs antigenemia following transplantation. Thirteen (50%) of the 26 recipients were HBs Ag positive during the period of dialysis and 13 developed HBs antigenemia 1 to 44 months following transplantation. Seventeen (65%) of the 26 HBs Ag positive patients had hepatic dysfunction which was detected by biochemical surveillance and not associated with clinical symptomatology. There was no evidence of progressive hepatic insufficiency. HBs Ag persisted in 24 (92%) recipients for 6 to 49 months. Clearing of antigenemia occurred in only two patients, both of whom ultimately rejected their grafts. The presence of HBs Ag had no adverse effect on graft function. Temporary reduction in azathioprine dosage with hepatic dysfunction was not associated with rejection episodes. The major hazard posed by the HBs Ag positive recipient is the potential reservoir for spread to the general population because of the persistence of antigenemia.     

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.     

Mycobacterial infections in renal allograft recipients

Primary mycobacterial infections developed in five of 565 patients who had transplants during a 15-year period. All had negative PPDs and normal chest roentgenograms; none had tuberculosis before transplantation. Atypical mycobacteria were cultured in three of five infections. All were treated with a multiple-drug regimen, including isoniazid, rifampin, ethambutol, and streptomycin sulfate. In four of five patients, there were serious drug-related complications. No major initial alteration of immunosuppressive therapy was necessary in any of the patients. During the study, a treatment policy was followed that included one year of isoniazid treatment of all recipients with a positive PPD, history of tuberculosis, chest x-ray film suggestive of tuberculosis, or PPD-positive donor. An additional 14 transplant recipients were treated in accordance with this policy without complications or subsequent mycobacterial infections (32-month average follow-up). Despite the low incidence of mycobacterial infection in this series, the potential lethality and morbidity mandate constant vigilance.     

Opportunistic infections in renal allograft recipients

Two major factors for successful organ transplantation are better control of rejection and better prevention and treatment of infections. In renal allograft recipients, immunosuppressive drug therapy is the major cause of immunocompromised status and occurrence of infections, which arise most commonly as a result of invasion by endogenous opportunists. It may also follow colonization by exogenous environmental organisms and via transfer of cytomegalovirus along with the transplanted kidney. The overall incidence of opportunistic infections varies from center to center; up to 15% of renal transplant recipients die of these infections. Clinical signs and symptoms of infection in immunocompromised patients may be concealed or imitated by the underlying disease, and a high index of clinical suspicion is vital. The unusual pathogens encountered in these patients demand thorough investigation. A total of 84 opportunistic infections encountered in renal allograft recipients during histopathologic and cytopathological evaluation of various specimens during the last 15 years is presented in this report. Invasive fungal infections were the most common pathogens, amounting to 55% of all infections. The dramatic increase in the diversity and number of opportunistic infections detected in these patients is not only due to an increasing population of susceptible individuals but also due to an improved recognition by advanced laboratory diagnostic techniques. The success of management of opportunistic infections depends on strong clinical suspicion, early diagnosis, and prompt treatment. The challenges of early diagnosis of opportunistic infections and prompt treatment are great; the rewards are even greater.