Clinical predictors of relapse after treatment of primary gastrointestinal cytomegalovirus disease in solid organ transplant recipients

Primary gastrointestinal cytomegalovirus (CMV) disease after solid organ transplantation (SOT) is difficult to treat and may relapse. Herein, we reviewed the clinical records of CMV D+/R- SOT recipients with biopsy-proven gastrointestinal CMV disease to determine predictors of relapse. The population consisted of 26 kidney (13 [50%]), liver (10 [38%]) and heart (3 [12%]) transplant recipients who developed gastrointestinal CMV disease at a median of 54 (interquartile range [IQR]: 40-70) days after stopping antiviral prophylaxis. Except for one patient, all received induction intravenous ganciclovir (mean+/-SD, 33.8+/-19.3 days) followed by valganciclovir (27.5+/-13.3 days) in 18 patients. Ten patients further received valganciclovir maintenance therapy (41.6+/-28.6 days). The median times to CMV PCR negativity in blood was 22.5 days (IQR: 16.5-30.7) and to normal endoscopic findings was 27.0 days (IQR: 21.0-33.5). CMV relapse, which occurred in seven (27%) patients, was significantly associated with extensive disease (p=0.03). CMV seroconversion, viral load, treatment duration, maintenance therapy and endoscopic findings at the end of therapy were not significantly associated with CMV relapse. In conclusion, an extensive involvement of the gastrointestinal tract was significantly associated with CMV relapse. However, endoscopic evidence of resolution of gastrointestinal disease did not necessarily translate into a lower risk of CMV relapse.

Viral infections in transplant recipients

Solid organ and hematopoietic stem cell transplant recipients are uniquely predisposed to develop clinical illness, often with increased severity, due to a variety of common and opportunistic viruses. Patients may acquire viral infections from the donor (donor-derived infections), from reactivation of endogenous latent virus, or from the community. Herpes viruses, most notably cytomegalovirus and Epstein Barr virus, are the most common among opportunistic viral pathogens that cause infection after solid organ and hematopoietic stem cell transplantation. The polyoma BK virus causes opportunistic clinical syndromes predominantly in kidney and allogeneic hematopoietic stem cell transplant recipients. The agents of viral hepatitis B and C present unique challenges particularly among liver transplant recipients. Respiratory viral illnesses due to influenza, respiratory syncytial virus, and parainfluenza virus may affect all types of transplant recipients, although severe clinical disease is observed more commonly among lung and allogeneic hematopoietic stem cell transplant recipients. Less common viral infections affecting transplant recipients include those caused by adenoviruses, parvovirus B19, and West Nile virus. Treatment for viruses with proven effective antiviral drug therapies should be complemented by reduction in the degree of immunosuppression. For others with no proven antiviral drugs for therapy, reduction in the degree of immunosuppression remains as the sole effective strategy for management. Prevention of viral infections is therefore of utmost importance, and this may be accomplished through vaccination, antiviral strategies, and aggressive infection control measures.

Kinetics of interferon-gamma producing cytomegalovirus (CMV)-specific CD4+ and CD8+ T lymphocytes and the risk of subsequent CMV viremia after allogeneic hematopoietic stem cell transplantation

BACKGROUND

Deficiencies in cytomegalovirus (CMV)-specific T lymphocytes impair the immunologic response against CMV reactivation after allogeneic hematopoietic stem cell transplantation (HSCT).

METHODS

A time-dependent analysis was conducted to determine the association between the percentages and kinetics of interferon-gamma-producing CMV-specific CD4+ and CD8+ T lymphocytes and CMV viremia among 30 allogeneic HSCT recipients.

RESULTS

Higher percentages of CD4+ T lymphocytes activated with CMVpp65 (hazard ratio [HR]: 2.06; 95% confidence interval [95% CI]: 1.18-3.6; P=0.011) and CMV lysate (HR: 1.18; 95% CI: 0.99-1.42; P=0.072), and higher percentages of CD8+ T lymphocytes activated by CMV immediate early-1 (HR: 1.2; 95% CI: 1.01-1.43; P=0.038) and CMVpp65 (HR: 1.12; 95% CI: 1.0-1.27; P=0.060) were associated with time-to-CMV viremia. Furthermore, a higher degree in the decline of CMV lysate-activated CD4+ T lymphocytes (HR: 1.14; 95% CI: 0.96-1.36; P=0.125) and CMVpp65-activated CD8+ T lymphocytes (HR: 1.36; 95% CI: 1.03-1.78; P=0.031) was suggestive of or significantly associated with time-to-CMV viremia.

CONCLUSIONS

Higher levels of CMV-specific CD4+ and CD8+ T lymphocytes were associated with subsequent CMV viremia after HSCT. The association between CMV viremia and the degree of decline in CMV-specific T lymphocytes suggests that severe disruption in homeostatic CMV-specific immune environment contributes to the immunopathogenesis of CMV after allogeneic HSCT.

Mycobacterium marinum infections in transplant recipients: case report and review of the literature

Infections due to Mycobacterium marinum are rarely encountered following organ and tissue transplantation. Herein, we report a case of M. marinum infection in a kidney and pancreas transplant recipient who manifested clinically with multiple locally spreading sporotrichoid-like cutaneous nodules in his left forearm. In order to provide a general overview of post-transplant M. marinum infections, we reviewed and summarized all previously reported cases of this infection that occurred after transplantation. Including our index case, all 6 cases presented with multiple cutaneous and subcutaneous nodules that had spread locally in the involved extremity. One patient had lesions located in non-contiguous body sites suggesting either systemic dissemination or multiple sites of inoculation. In all but 1 patient, the cutaneous nodules appeared in an ascending pattern and following exposure to fish tanks or after contact with the marine environment. The diagnosis of M. marinum infection was suspected on clinical grounds and confirmed by mycobacterial culture. Treatment consisted of at least 2 active antibiotics (such as rifamycins, ethambutol, tetracyclines, or macrolides) for 4-9 months, resulting in clinical cure or improvement. Relapse was observed in 1 patient despite completing 6 months of antibiotic therapy. One patient had surgical excision of the lesions. In conclusion, M. marinum should be considered as the cause of cutaneous and subcutaneous nodules in transplant recipients, particularly in the context of fish tank or marine exposure. Compared with the immunocompetent hosts, M. marinum infection may have a more aggressive clinical course after transplantation, and may require a longer duration of antibiotic treatment. Early diagnosis and treatment may prevent local spread and potential systemic dissemination.

Clinical features and outcomes of cytomegalovirus retinitis after transplantation

Cytomegalovirus (CMV) infection of the retina is a rarely encountered end-organ disease after transplantation. In order to describe the clinical characteristics and outcomes of CMV retinitis after hematopoietic stem cell and solid organ transplantation, we performed a retrospective review of all cases of CMV retinitis at the Mayo Clinic (Rochester, Minnesota) during 1990-2004. During this 15-year period, CMV retinitis was diagnosed in 14 eyes of 9 patients who had received kidney (n=5), liver (n=2), heart (n=1), and autologous hematopoietic stem cell transplant (n=1). The mean age of the patients was 58 (standard deviation+/-11) years; 6 were male. The median time to diagnosis of CMV retinitis was 9 months (range, 4 months to 13 years) after transplantation. Four (44%) patients had concomitant pneumonitis or hepatitis. Five (55%) patients had bilateral retinitis. Retinal involvement was <or=10% in 8 eyes, >10% but <or=50% in 4 eyes, and >50% in 2 eyes. All patients received induction therapy with intravenous ganciclovir (n=8) or foscarnet (n=1) for a median of 43 days (range, 14-100 days) followed by maintenance therapy with intravenous or oral ganciclovir for a median of 88 days (range, 36-943 days) in 6 (67%) patients. One patient developed bilateral immune recovery uveitis during treatment, and later on progressed to develop rhegmatogenous retinal detachment. During the mean follow-up period of 20 months, visual acuity improved in 4 (28.5%), was stable in 4 (28.5%), and worsened in 6 (43%) eyes. CMV retinitis recurred in 2 patients. In conclusion, CMV retinitis is a rare, progressive, and highly morbid infectious complication of transplantation. The severity of clinical disease at the time of diagnosis may predict poor outcome. Hence, early intervention may be crucial to prevent its progression to irreversible visual loss.