Cytomegalovirus: Clinical virological correlations in renal transplant recipients

Comparison of rates of virus isolation from leukocyte populations separated from blood by conventional and Ficoll-Paque/Macrodex methods

One hundred fifty-two blood specimens, largely from immunocompromised patients, were collected in heparinized Vacutainer tubes and divided into paired aliquots of equal volume. Buffy-coat preparations, containing mixed leukocyte and separate mononuclear and polymorphonuclear leukocyte populations were obtained by treatment of blood with conventional and Ficoll-Paque/Macrodex (F-P/M) methods. The development of cytopathic effect in monolayers of WI-38 fibroblasts inoculated with cell suspensions derived from the two methods was used to assess virus infectivity. Twice as many virus isolations were obtained using F-P/M. Of those viruses isolated by both conventional and F-P/M, the development of cytopathic effect was more extensive using the latter method. Moreover, a greater variety of viruses was isolated using F-P/M method, as compared to the conventional method. The F-P/M method is no more time consuming than conventional procedures, is readily adaptable for use in the diagnostic virology laboratory, requires only minimal additional cost, and is a particularly suitable and effective means of monitoring viremia.

"Triple infections" (fungal, bacterial and viral) in immunosuppressed renal transplant recipients

In a period of 5 years, 8 out of 77 renal transplant patients showed simultaneous fungal, bacterial and viral infections. Candida albicans was found in all cases. The most severe bacterial complications were infections with Klebsiella, Pseudomonas and Staphylococcus aureus. Cytomegalovirus, persistent HBsAg positive hepatitis, herpes zoster, and herpes simplex infections were also found. Seven patients died of bacterial superinfection and miliary tuberculosis. The data presented show that "triple infections" are associated with high mortality and that miliary tuberculosis occurred frequently in immunosuppressed renal transplant recipients.

Seroconversion to human-cytomegalovirus-specific pre-early nuclear antigens in renal transplant recipients

Seroconversion to human cytomegalovirus (H-CMV)-specific antigens was observed in 8 out of 9 renal transplant recipients. In 7 of the 8 recipients antibody to "pre-early nuclear antigens" (PENA), which are detectable in human embryonic lung cells within 1 hr of H-CMV infection by anti-complement immunofluorescence staining, developed concomitantly with the increase in other antibodies including anti-early antigens (EA), anti-nuclear inclusions (NI), and complement-fixing (CF) antibody in 1--2 months after transplantation. About 1 year later, anti-PENA and anti-EA titers were concomitantly decreased in 2 recipients, whereas anti-NI and CF antibody titers were maintained at elevated levels in all the seroconverted recipients. These results support the idea that the development of antibody to PENA, like antibody to EA, may represent a current or recent infection with (or reactivation of) H-CMV. In one patient, antibody to PENA did not develop through the observation period despite increases in antibody to EA and other antibodies; this lends support to immunological distinctness of PENA from EA.

Gastrointestinal complications of renal transplantation. 2. The colon

In 95 consecutive cases of cadaveric renal transplantation followed up for 1 to 83 months (mean 23.1 months) seven colonic complications developed in seven patients; these included ischemic colitis in three, colonic perforation in two, fecal impaction in one and appendicitis in one. Except for appendicitis all the complications occurred within 2.5 months of transplantation and were not related to the patient's age, sex, blood group, or use of cigarettes or alcohol, the duration of hemodialysis before transplantation, the tissue match or the number of infusions of immunosuppressive medication. Two patients died, but not of the complication. In the management of free colonic perforation prompt resection or exteriorization, with avoidance of intraperitoneal suture lines, and continuous postoperative peritoneal lavage may be lifesaving. Early surgical intervention and creation of a colostomy in one of the cases of ischemic colitis proved helpful.

Jaundice after renal allotransplantation

Of 567 patients receiving renal transplantation at the University of Minnesota between October 1967 and October 1975, 22 developed clinical jaundice. Of these 22, nine died with their initial episode of hepatitis, six died within three months of causes associated with liver malfunction, four developed evidence of chronic hepatic failure and only three totally recovered from their illness. Five had clear evidence of Australia antigen positive hepatitis B, four of cytomegalovirus hepatitis, two of herpes hominis hepatitis, one of varicella zoster hepatitis and three of hepatic failure associated with systemic bacterial and/or fungal sepsis. Two of the 22 patients were thought likely to have cytomegalovirus hepatitis though definite proof was absent and in five patients a clear-cut etiology could not be made. In many of these patients the diagnosis was confounded by the previous presence of HB(s)Ag antigen and the frequent occurrence of a previous or concurrent infection with cytomegalovirus. The role of various drugs including azathioprine, sulfisoxazole, chlorpromazine, acetominophen, etc., could not be established but major roles for these agents in the face of the many viral and bacterial infections present in these patients is doubted. No clear-cut therapy could be established although it appears safe to discontinue azathioprine for longer or shorter periods of time with or without substitution of cyclophosphamide without serious deterioration of renal function. The problem of hepatic failure in transplant patients is still unsolved and will require a prospective study of etiologic agents and sub-clinical hepatic dysfunction in order to establish even the first principles of clinical-pathological correlation.

Viral infection-homograft interactions in a murine model

The effects on some host defenses of murine cytomegalovirus (MCMV) and(or) EL(4), a mouse ascites homograft, were studied in mice. Assays of cellular and humoral immunity in response to either or both of these perturbations were carried out by quantitation of various immune activities.Limited studies demonstrated no effect of EL(4) inoculation on the host response to MCMV by organ viral titer, duration of viral persistence, or anti MCMV complement-fixing antibody titer. Prior infection with MCMV, however, resulted in greatly reduced numbers of splenocytes, the source in this study of immune effector cells. Residual splenocytes demonstrated less response to both phyto-hemagglutinin and lipopolysaccharide, particularly in the 2-3-wk interval after infection. Similarly, responder cells in mixed lymphocyte cultures were less reactive when derived from infected animals. Lymphocyte-mediated cytolysis of EL(4) was significantly less in mice infected on the day of and 7, 14, and 21 days before the tumor homograft with a return to control levels by 28 days. 90% of the cell-mediated cytolysis could be eliminated by treatment with anti-theta serum. Serum-mediated cytolysis of EL(4) was also reduced in infected animals. No suppressor cells or serum inhibitory factors could be identified in infected animals. Although alternative explanations exist, this study suggests that in infected animals there is a significant reduction in both the number and function of bone marrow-derived and thymus-derived cells directed against the alloantigens in EL(4).

Fungal infections in renal transplant recipients

Infection continues to be a major source of morbidity and the major source of mortality in renal transplant recipients who are susceptible to opportunistic infections. We recently reviewed all renal transplant recipients who had fungi cultured during a three year period. C. albicans and T. glabrata were cultured most frequently. Deep fungal infections occurred in many patients and were frequently observed late in the course of bacterial and viral infections. Ten patients had fungemia, and primary fungal pneumonia occurred in eight patients. Three patients had fungal infection of the central nervous system. Three of eight patients with fungal pneumonia and eight of ten patients with fungemia died as a result of their fungus infections. These patients frequently had poor renal function and were receiving high steroid doses or had recently been treated for kidney rejection. One patient with fungal pneumonia and six patients with fungemia had the fungus cultured from a superficial site. Several patients developed fungal infections late in the course of viral or bacterial infections. Amphotericin-B and 5-fluorocytosine remain the mainstays of antifungal therapy.

Double-blind study of interferon administration in renal transplant recipients

In a double-blind trial renal allograft recipients were treated with fibroblast interferon preparations for 3 months in an attempt to prevent viral infections. Interferon therapy did not reduce the overall incidence of viral infections. No adverse effects were noted on liver function, platelet counts, or leucocyte counts, or acute rejection episodes.

Clinical manifestations of infections with herpesviruses after kidney transplantation: a prospective study of various syndromes

Herpesviruses infections occur commonly following kidney transplantation and immunosuppression, and contribute substantially to morbidity in the transplant recipient. In this prospective study, stomatitis, mononucleosis, hepatitis, or interstitial pneumonia occurred in 24 of 30 patients (80%) as a result of reactivation of latent herpesvirus infections, but the majority of these syndromes were self-limited and the infections were often asymptomatic. Rejection occurred significantly more frequently in CMV-infected patients, but a distinct causal relationship cannot be deduced.

Cytomegalovirus infection and graft survival in renal graft recipients

We have studied 85 patients who received a renal transplant for CMV infection as well as for herpes simplex (HSV), herpes zoster (HZ), measles, mumps, rubella and hepatitis B. We found no evidence of primary or secondary infections for the non herpetic viruses except for hepatitis B infection that occurred in 17 per cent of the patients. CMV infection occurred in 87 per cent of the patients while antibody rises to HZ and HSV occurred in 30 and 13 per cent of the patients, respectively. The CMV infections occurred 2 to 4 months after the transplantation (mean time 11.1 weeks) and seemed to trigger the first episode of renal rejection that occurred earlier in the CMV infected group (mean time 12.1 weeks) than in the uninfected group (mean time 18.6 weeks). This difference in time is highly significant, p less than 0.001). However these CMV injections did not decrease the longterm survival of the grafted kidneys.

Search for latent cytomegalovirus in renal allografts

Cytomegalovirus (CMV) infection is common after renal transplantation, and cytomegaloviruria occurs in about two-thirds of the recipients. These observations suggest that the allografts may be a site of latent infection with CMV and its reactivation may be the source of viruria. To investigate this possibility, 130 kidney specimens from 85 persons were cultured, and simultaneous explants were made of 63 of them from 50 people. No CMV was received from 33 normal kidney or cadaver donors or from 19 allograft recipients who had no evidence of posttransplantation infection with CMV. The experiment included 37 primary organ explants that yielded no evidence of latent virus. Among 33 allograft recipients with posttransplantation CMV infection, overt infectious virus was isolated from 6 of 57 allograft biopsies. All six positive specimens were from four patients, all of whom had viruria simultaneously. Organ explants from 20 of the recipients with demonstrated postoperative CMV infection, including 13 viruric patients, failed to unmask any latent CMV. Thus, allograft kidneys were infrequently infected with CMV (6%), even in patients with viruria (24%). The kidney parenchyma appears to be an uncommon site of latent CMV infection and may not be the usual source of virus in patients with viruria.

Cytomegalovirus retinitis secondary to chronic viremia in phagocytic leukocytes

We studied the relationship between the duration and intensity of cytomegalovirus viremia, cytomegalovirus complement fixing antibody, and cytomegalovirus retinitis in 61 renal transplant recipients. Five (8%) patients had chronic viremia which lasted more than six months. Two of the five developed typical cytomegalovirus retinitis and a severe fungal infection after intensive viremia of more than 11 months' duration. Retinitis did not develop in 22 patients with short-term viremia. Infectious cytomegalovirus was largely associated with polymorphonuclear leukocytes, but the virus was associated with monocytes during the immature granulocytic response accompanying one patient's terminal illness.

BK antibody and virus-specific IgM responses in renal transplant recipients, patients with malignant disease, and healthy people

Haemagglutination-inhibition (HAI) antibodies to BK virus, including BK-virus-specific IgM, were determined before and after renal transplantation in 20 patients, in 57 patients with malignant disease, and in 66 healthy controls, Before transplantation 11 of the renal transplant recipients were seronegative, but eight later serocconverted, two before and six after transplantation. Twenty of the patients with malignant disease and 22 controls were also seronegative. The geometric mean titre of BK HAI antibodies was significantly higher among transplanted patients (1/180) than among controls (1/90). BK-virus-specific IgM antibody was detected in seven renal transplant recipients, six patients with malignant disease, and 13 healthy controls. In transplant recipients BK-virus-specific IgM antibody usually persisted throughout the duration of the study, and studies on controls from whom second serum samples were available suggested that they too had persistent BK-virus-specific IgM responses. The geometric mean titre of BK-virus-specific IgM HAI antibody was significantly greater in post-transplantation sera (1/223) than in control sera (1/28). The specificity of the detection of BK-virus-specific IgM HAI antibody was confirmed by direct visualisation of antibody by immune electron microscopy. The persistence of BK-virus-specific IgM suggested that BK virus continued to provide an antigenic stimulus. Nevertheless, there was no obvious association between the serological findings and any clinical features, and prospective studies will be needed to elucidate any such association.

Pseudorejection: factors mimicking rejection in renal allograft recipients

Serum creatinine level is used as a major measure of post-transplant renal function at most centers. A significant elevation of creatinine level suggests allograft rejection. However, other factors affect renal function in the transplant recipient and each may cause an elevation in serum creatinine level, suggesting a rejection episode. It is important to make the correct diagnosis and not treat these episodes with anti-rejection therapy. We reviewed the course of patients transplanted between 1969 and 1974 to determine the pathogenesis of creatinine elevations retrospectively found to be due to causes other than rejection. Six distinct causes were found: hyperglycemia, ureteral obstruction, infection, lymphocele, arterial stenosis, and recurrence of the original disease. Each of these is discussed individually. In order to make the diagnosis of pseudorejection, a high index of suspicion is necessary.

Infectious mononucleosis and mononucleosis syndromes

Infectious mononucleosis (IM) and cytomegalovirus (CMV) mononucleosis are caused by a primary infection with related viruses, Epstein-Barr virus (EBV) and CMV. Despite the similarity of clinical manifestations, basic differences exist: (1) The heterophil antibody (HA) response is absent in CMV mononucleosis, whereas it is present in IM. (2) In IM atypical lymphocytosis reflects proliferation of B cells early and of T cells later in the disease course; in CMV mononucleosis the situation appears complex. (3) In blood, EBV is restricted to B lymphocytes, whereas CMV is found in polymorphonuclear and mononuclear leukocytes. (4) Complications of CMV mononucleosis such as hepatitis and pneumonitis may be due to virus cytopathic effect in target organs. Prominent tonsillopharyngitis with adenopathy, and visceral complications of IM are related to lymphoproliferation which is self-limited except in males with a rare familial defect in defense against EBV. Immune complex-mediated pathology may occur in both diseases. (5) CMV is frequently transmitted to a fetus in utero or to an infant during or after birth, and this occasionally leads to severe cytomegalic inclusion disease; vertical transmission of EBV appears to be exceptional. (6) Secondary EBV infections are associated with certain malignancies whereas such an association has not been recognized in the case of CMV. Toxoplasma gondii is another cause of HA-negative mononucleosis. Its complications in the heart, in skeletal muscle and in the central nervous system are related to direct invasion by the parasite. Cellular immunity plays an important role in defense against all three agents.

Post-transplant malignant lymphoma. Distinctive morphologic features related to its pathogenesis

Malignant lymphoma developed in two patients after renal transplantation. In both, the central nervous system was involved. Histologic study of the tumors showed that they were composed of a monomorphous proliferation of cells characterized by a large vesicular nucleus, prominent basophilic nucleolus and strongly pyroninophilic cytoplasm. The tumors thus would be classified as "diffuse large lymphoid lymphomas with pyroninophilia" or "immunoblastic sarcomas" as described in the literature. Tumor cells resembled cells observed in the paracortex of antigenically stimulated lymph nodes, cells from malignant lymphomas in mice that were antigenically stimulated and from malignant lymphomas in patients with immunodeficiency diseases or autoimmune disorders. The distinctive morphologic features of the tumors in the transplant recipients described provide further evidence that long-term antigenic stimulation may be important in their pathogenesis.

Condyloma acuminatum of the bladder

Condyloma acuminatum in the bladder of 2 patients on immunosuppressive therapy after kidney transplantation is described. The successful treatment was transurethral electroresection and coagulation. We do not recommend radical operations in cases of condyloma acuminatum. Resected specimens should be examined pathologically to exclude papillary epithelial tumors.

Cytomegalovirus replication and the host immune response

Cytomegalovirus (CMV) is closely associated with host cellular structures, and this has a significant impact upon the immunologic response following infection. CMV may be recovered from a variety of body secretions and fluids during acute infection, and protracted shedding may supervene in some instances. The reasons for a variable host response to CMV infection remain unclear, and the mechanisms responsible for the establishment of persistence have not been worked out. CMV persistence and latency are discussed, and some recently derived relevant data are presented. An animal model has been developed consistent with clinical observations pertaining to CMV transmission with blood. Results obtained in the course of these and other studies support the concept of immunological activation of latent CMV. The timing of CMV infection relative to an unrelated antigenic challenge is probably critical in determining the emergence of immunodepression or enhancement. Some aspects of CMV sero-diagnosis are also reviewed.

Transmission of cytomegalovirus infection with renal allograft

Fifty-four patients who received a renal allograft between October 1971 and October 1974 were followed prospectively to correlate pretransplant serum antibody to cytomegalovirus (CMV) with shedding of CMV following transplantation. Twenty-five of 54 patients had antibody demonstrable to CMV using immunofluorescent techniques, but only 20 of 54 using complement-fixing techniques. All 24 who had antibody and survived one month or longer, and seven of nine without antibody but who received a kidney from a seropositive donor shed virus after transplantation, whereas none of 12 individuals without antibody and who received a kidney from a seronegative donor (P less than 0.005) shed virus. Three of eight other seronegative patients for whom donor sera were not available for analysis shed virus. Viremia occurred in eight of ten individuals who developed new antibody after transplantation, versus seven of 24 with antibody prior to transplant (P less than 0.02), and virus shedding in seroconverters from other sites was significantly more persistent than in pretransplant antibody-positive patients. Thus, CMV infection was due either to reactivation of latent infection or was transmitted along with the renal allograft and manifested as a primary infection.

Pregnancy following renal transplantation

From 1968 through 1974 at the University of Minnesota there were 17 pregnancies in 12 patients who were renal transplant recipients. Three were cadaver transplants and nine were transplants from living related donors. In eight patients there were two first-trimester pregnancy termination, three mid-trimester abortions by hysterotomy, and one spontaneous abortion. Two of the induced abortions were in patients with ileal conduits. There were no unusual major obstetric complications but toxemia of pregnancy and concurrent bacterial and viral infections were common medical problems. Of the liveborn infants, only three of the 12 were small for their gestational age, seven were of appropriate size, and two were large. There were no neonatal problems and no congenital anomalies. Renal function during pregnancy was carefully monitored and was compromised in three of the patients studied. One patient had three pregnancies, including the delivery of a set of twins. Several months following her third delivery she developed fatal hepatitis. Two patients developed carcinoma in situ of the cervix. Pregnancy following renal transplantation is not without risk. Sexually active female transplant recipients should be counseled regarding pregnancy and sterilization should be offered as an option at the time of transplantation.

Chronic antigenic stimulation, herpesvirus infection, and cancer in transplant recipients

An increased incidence of malignancy has been reported in transplant recipients. The pathogenesis of this increase was originally attributed to immunosuppressive therapy. However, not all tumours are increased in proportion to their occurrence in the general population-75% of reported tumours are lymphorproliferative or carcinoma of the skin, lip, or cervix. This cannot be explained by impaired immunosurveillance, and alternative hypotheses must be considered. 90% of transplant recipients develop clinical or serological evidence of herpesvirus infection. Herpesviruses have been implicated in the pathogenesis of lymphorproliferative tumours and carcinoma of the skin and cervix. They can remain in latent form and be reactivated by allogeneic stimulation and/or immunosuppression. These viruses localise to skin, cervix, and neural tissue-i.e., exactly those sites where cancer develops in transplant patients. Herpesvirus infections in association with the presence of an allogeneic graft in an immunosuppressed patient may be responsible for the increased incidence of both lymphoproliferative tumours and carcinoma of the skin, lip, and cervix in the transplant recipient.