Cytomegalovirus infection in kidney transplant patients: clinical manifestations and diagnosis

Prevalence and Impact of Cytomegalovirus Primary Infection and Reactivation on Graft Function in Post-Renal Transplant Recipients

Introduction Cytomegalovirus (CMV) is often associated with mortality and significant morbidity following renal transplantation leading to graft rejection or dysfunction. Primary CMV infection refers to the first detection of the virus in a person who has no prior evidence of CMV exposure before transplantation. CMV has a unique property called latency. After the initial infection, CMV can enter a dormant state within the body, residing in myeloid cells without causing active disease. CMV reactivation is likely when a latent CMV infection switches to a lytic phase of replication, which can be detected using IgG avidity ELISA. Aims and objectives This study aims to assess the prevalence of primary CMV infection and reactivation in renal transplant recipients, evaluate the impact of CMV infection on graft function following transplantation, and identify the risk factors and comorbidities associated with CMV-related graft rejection. Methodology During the study period from March 2020 to November 2021, blood samples were collected from 46 CMV-positive (by PCR) renal transplant recipients, and serum was separated and stored. IgG avidity ELISA test was performed, which served as a valuable tool to differentiate primary infection from reactivation due to difference in binding strength where low binding strength (low avidity<30%) indicated primary infection and high binding strength (high avidity>40%) indicated reactivation. All these patients were followed up to study the impact of CMV on graft functions. Results The age-wise distribution of patients shows a maximum number of cases under 40 years. The gender distribution of cases shows a higher preponderance of males (76%) compared to females (24%). The clinical presentation showed CMV syndrome as the most common (50%), followed by CMV colitis (37%), CMV nephritis (9%), CMV pneumonitis, CMV esophagitis, and CMV duodenitis, each comprising 2%. After performing the IgG avidity test, CMV infection with maximum cases of reactivation (87%) followed by primary infection (13%) was observed. The investigations related to renal dysfunction such as serum creatinine showed >3 mg/dL (85% of cases), 2.1-3 mg/dL (4.33% of cases), 1.6-2 mg/dL (2% of cases), 1-1.5 mg/dL (4.33% of cases) in decreasing order. Normal urea values are seen in 9% of cases followed by the range between 24 and 55 mg/dL in 67% and >100% in 24% of cases. The graft rejection based on the biopsy report showed that acute cellular rejection (ACR) (72%) was higher followed by antibody-mediated rejection (ABMR) with 15% and then ACR + ABMR with 4%. No rejection was found in 9% of cases. Renal dysfunction showed a higher preponderance to chronic graft dysfunction (67%) followed by acute graft dysfunction (24%) and stable graft function among 9% of cases. A comparison of graft dysfunction in primary infection/reactivation was assessed, and it was found that acute graft dysfunction was more common in primary infection. In the case of reactivation, chronic graft dysfunction was more common. Conclusion This study focuses on the microbiological dimensions and the critical role of CMV antibody screening. It underscores the necessity of vigilant monitoring and prophylactic antiviral therapy to reduce CMV infection risks and enhance patient outcomes. It also highlights the use of IgG avidity testing to differentiate between primary infection and reactivation, facilitating timely and effective interventions to prevent graft dysfunction and rejection.

Late-onset cytomegalovirus cholangiopathy in a renal transplant patient: Case report and review of the literature

This case report highlights the investigation and treatment of a 70-year-old male with cytomegalovirus (CMV) cholangiopathy. The patient underwent a kidney transplant in 2016 and presented 3 years later with the atypical presentation of left shoulder pain associated with dilated biliary tree and mild transaminitis. Initial endoscopic retrograde cholangiopancreatography (ERCP) showed diffuse stricture of the common bile duct, requiring stenting, and over the course of a year multiple stent changes were required to prevent cholestasis. CMV polymerase chain reaction (PCR) tests were conducted on bile duct brushings and found to be positive. Oral valganciclovir was given for 6 weeks but the strictures did not resolve. He underwent a laparoscopic total choledochectomy and hepaticojejunostomy as definitive treatment. CMV involvement of the biliary tract has rarely been reported in kidney transplant patients. Antiviral therapy in the form of ganciclovir or valganciclovir is often sufficient to eradicate CMV infection and improve clinical disease. Surgical management should be considered only if the patient has failed medical therapy, or if there is suspicion of malignancy. This case shows that in renal transplant patients presenting with cholangiopathy, CMV disease should be considered as a possible differential even in patients without early CMV infection or with prior CMV prophylaxis.

Cytomegalovirus and Aspergillus spp. coinfection in organ transplantation: a case report and review of the literature

With the advent of potent immunosuppressive options, acute rejection episodes have decreased at the expense of increased incidence of opportunistic infections in solid organ recipients. In the absence of any preventive therapy, 30–75 % of transplant recipients develop cytomegalovirus (CMV) infection. Candida spp. and Aspergillus spp. account for more than 80 % of invasive fungal infections in solid organ recipients. This co-occurrence of two commonly seen opportunistic infections may end up in fatality. Here, we present a case of concomitant Aspergillus spp. and CMV infection and discuss the relevant literature. A 54-year-old male patient presented with fever, shortness of breath, and chest pain on the 9th posttransplant week after renal transplantation. CMV-DNA by polymerase chain reaction (PCR) was 1,680,000 copies/ml, thus, valganciclovir dose was increased. There were inspiratory crackles at both lung bases, and chest computed tomography (CT) revealed multiple fungal balls throughout the right lung. Galactomannan antigen was positive, and voriconazole and other antimicrobials were subsequently added to the treatment. At the end of the therapy, on control CT, pneumonic consolidation had disappeared, sputum cultures didn’t show Aspergillus spp., and CMV-DNA reduced to 700 copies/ml. The patient showed a favorable clinical response to combined treatment; fever, dyspnea, and pleuritic chest pain disappeared. Both CMV disease and aspergillosis may present as pulmonary disease; thus, the characterization of one may not preclude the search for the other and the timely initiation of treatment is of paramount importance for good outcomes.

Fatal case of Aspergillus coinfection in a renal transplant recipient suffering from cytomegalovirus pneumonitis (Case Report)

Cytomegalovirus (CMV) disease is common in postrenal transplant recipients, and may predispose the patients to secondary bacterial or fungal infections. However, simultaneous coinfection is rare and often makes diagnosis difficult. We report a case of CMV pneumonitis in a renal transplant recipient presenting with elevated CMV pp65 antigen level and abnormal chest radiograph. Despite potent and broad-spectrum antimicrobial therapy, his condition deteriorated rapidly - he soon went into respiratory failure, septic shock and died several days later. Transbronchial biopsy and bronchoalveolar lavage obtained before the patient's death showed evidence of invasive pulmonary aspergillosis with concomitant CMV pneumonitis. High index of suspicion and early and empirical initiation of antifungal therapy may be necessary for successful management of fulminant pneumonia in solid organ transplant recipients.

Challenges and directions for the pathogen hypothesis of Alzheimer's disease

This paper critically reviews the possibility that infiltration of the brain by pathogens (e.g. Herpes simplex virus type 1 (HSV1) or Chlamydophila pneumoniae (Cp)) acts as a trigger or co-factor for Alzheimer's disease (AD). The evidence currently available is limited and in some cases inconsistent, but it does justify the need for more vigorous investigation of this hypothesis. An issue of particular concern is the paucity of experimental evidence showing that pathogens can elicit the neuropathological changes and cognitive deficits that characterise AD. Other weaknesses include a failure to obtain independent confirmation of Cp in AD brains, and a lack of evidence for HSV1 proteins or intact virions in AD brain tissue. Future avenues of investigation that might prove fruitful include epidemiological investigations of the incidence of AD in individuals who are either immunosuppressed or have received chronic antiviral or antibiotic therapy. There is also a need to consider systemic infections as potential contributors to the pathogenesis of AD.