Cytomegalovirus-induced tubulointerstitial nephritis in a renal allograft treated by foscarnet therapy

Have we missed AINything? Acute interstitial nephritis in SARS-CoV-2 infection and vaccination

Acute interstitial nephritis (AIN), defined by the presence of interstitial inflammation accompanied by tubulitis, is an often overlooked cause of acute kidney injury (AKI). It is now well established that SARS-CoV-2 infection can cause a wide variety of kidney injuries, most commonly acute tubular injury and collapsing glomerulopathy. In comparison, AIN is rarely documented in association with SARS-CoV-2 both anecdotally and in larger series of autopsy or biopsy studies. In this issue of the Journal, León-Román describe 5 cases of AIN in patients with a history of COVID-19 and highlight AIN as a possibly under-reported or ignored facet of renal disease associated with SARS-CoV-2. They describe three scenarios in which AIN can be seen: 1) SARS-CoV-2 infection after diagnosis of AIN, 2) AIN followed by SARS-CoV-2 infection in the same admission and 3) Severe SARS-CoV-2 and AIN possibly associated with SARS-CoV-2 itself. Overall, AIN remains rare in SARS-CoV-2 and causality is difficult to ascertain. Interestingly, AIN is not only seen in association with the disease itself but also with SARS-CoV-2 vaccination. This scenario is equally rare and causality is no less difficult to prove. A history of preceding SARS-CoV-2 infection and vaccination should be actively sought when patients present with otherwise unexplained AIN.

Cytomegalovirus infection in kidney allografts: a review of literature

Cytomegalovirus (CMV) is an important cause of renal transplantation complications. It can cause different syndromes or end-organ diseases that can lead to unfavourable clinical outcomes and kidney allograft dysfunction. Although well documented as a systemic disease on renal transplant patients, affecting non-renal tissue, as gastrointestinal and respiratory tract, few cases have been reported in English-language indexed journals involving renal allograft lesions secondary to CMV. As an important differential diagnosis and etiological agent to acute and chronic rejection, the possibility of CMV kidney direct infection needs prompt recognition for effective treatment. In this paper, we will review the current literature about CMV nephritis and discuss the findings from each case report.

Delayed-onset cytomegalovirus disease coded during hospital readmission after kidney transplantation

BACKGROUND

Use of prophylactic anti-CMV therapy for 3 to 6 months after kidney transplantation can result in delayed-onset CMV disease. We hypothesized that delayed-onset CMV disease (occurring >100 days posttransplant) occurs more commonly than early-onset CMV disease and that it is associated with death.

METHODS

We assembled a retrospective cohort of 15,848 adult kidney transplant recipients using 2004 to 2010 administrative data from the California and Florida Healthcare Cost and Utilization Project State Inpatient Databases. We identified demographic data, comorbidities, CMV disease coded during readmission, and inpatient death. We used multivariate Cox proportional hazards modeling to determine risk factors for delayed-onset CMV disease and inpatient death.

RESULTS

Delayed-onset CMV disease was identified in 4.0%, and early-onset CMV disease was identified in 1.2% of the kidney transplant recipients. Risk factors for delayed-onset CMV disease included previous transplant failure or rejection (HR 1.4) and residence in the lowest-income ZIP codes (HR 1.2). Inpatient death was associated with CMV disease occurring 101 to 365 days posttransplant (HR 1.5), CMV disease occurring greater than 365 days posttransplant (HR 2.1), increasing age (by decade: HR 1.5), nonwhite race (HR 1.2), residence in the lowest-income ZIP codes (HR 1.2), transplant failure or rejection (HR 3.2), previous solid organ transplant (HR 1.7), and several comorbidities.

CONCLUSION

These data showed that delayed-onset CMV disease occurred more commonly than early-onset CMV disease and that transplant failure or rejection is a risk factor for delayed-onset CMV disease. Further research should be done to determine if delayed-onset CMV disease is independently associated with death.

Cytomegalovirus glomerulopathy in a kidney allograft with response to oral valganciclovir

Cytomegalovirus is an important viral pathogen in the kidney transplant population. Reports of direct cytopathic effects of cytomegalovirus in the kidney allograft are infrequent, with the majority of earlier reports highlighting tubulointerstitial involvement. We report a 58-year-old man who presented with an acute decrease in kidney allograft function 3 months posttransplantation. At presentation, both cytomegalovirus and polyomavirus blood polymerase chain reaction results were positive. Biopsy showed predominant glomerular endothelial involvement by cytomegalovirus with positive immunohistochemistry results. Polyomavirus was not detected in the biopsy specimen. He was treated with oral valganciclovir and a decrease in immunosuppression. He had a complete response, with clearance of viremia and return of allograft function to baseline. Recent reports of glomerular involvement may reflect changing practices in antiviral chemoprophylaxis and immunosuppressive regimen. Oral valganciclovir may have a role in the treatment of patients with mild viremia with tissue-invasive kidney disease.

Acute Adenoviral Infection of a Graft by Serotype 35 Following Renal Transplantation

Adenoviral infections of immunocompetent patients usually present as self-limiting pharyngitis, gastroenteritis, urocystitis, or conjunctivitis. In immunosuppressed patients, development of the illness can be severe, even life-threatening or fatal, and therapeutical intervention is difficult. Previous case reports of adenoviral infections after kidney transplantation have described a symptomatology of hemorrhagic cystitis, fever, renal dysfunction, and rarely fatal systemic dissemination. Here we report on a 46-year-old female renal transplant recipient suffering from adenoviral serotype 35 nephritis of the donor organ 29 days after transplantation. In this case, the main symptoms of the adenoviral infection were high fever and progressive renal failure of the transplanted organ. At the peak of the clinical symptoms, owing to histological and immunohistochemical evaluations of a kidney biopsy, we were able to establish the diagnosis in time so that adequate therapy could be employed. Immunosuppression was reduced and modified, and a self-limiting course of the infection was observed, followed by significant improvement of graft function. Subsequent to histological diagnosis, adenoviral particles were isolated from urine and identified as adenovirus serotype 35. Adenoviral nephritis of the transplanted organ should be considered in the differential diagnosis of persistent anuria after kidney transplantation. Our case highlights the importance of applying all possible diagnostic techniques, including histological evaluation of renal biopsies.

Cytomegalovirus-induced glomerular vasculopathy in renal allografts: a report of two cases

Cytomegalovirus (CMV) remains a major viral pathogen complicating renal transplantation. Tubulointerstitial nephritis is the commonly acknowledged and well-characterized pathologic feature of renal allograft CMV disease. There is controversy about whether there is a distinct entity as a CMV glomerulopathy in the absence of tubulointerstitial disease. We describe two patients with renal allograft dysfunction who displayed distinct features of CMV glomerular vasculopathy, in the absence of overt viral cytopathic changes involving the tubules.

Infections in recipients of kidney transplants

A review of infections in kidney transplant recipients is presented in this article, beginning with a discussion of the pretransplant infectious diseases evaluation and an overview of the timing of infectious posttransplant, and then focusing on individual types of infection.