BK Virus: A Cause for Concern in Thoracic Transplantation?

Abstract

Human BK polyomavirus (BKV) infection is poorly documented in heart and lung transplant patients. BK viruria and viremia have been estimated to affect 19% and 5% of heart transplant recipients, respectively. Data are limited, especially for lung transplantation, but the proportion of patients progressing from BK viruria to viremia or BKV-related nephropathy (BKVN) appears lower than in kidney transplantation. Nevertheless, a number of cases of BKVN have been reported in heart and lung transplant patients, typically with late diagnosis and generally poor outcomes. Risk factors for BKV infection or BKVN in this setting are unclear but may include cytomegalovirus infection and anti-rejection treatment. The relative infrequency of BKVN or other BK-related complications means that routine BKV surveillance in thoracic transplantation is not warranted, but a diagnostic workup for BKV infection may be justified for progressive renal dysfunction with no readily-identifiable cause; after anti-rejection therapy; and for renal dysfunction in patients with cytomegalovirus infection or hypogammaglobulinemia. Treatment strategies in heart or lung transplant recipients rely on protocols developed in kidney transplantation, with reductions in immunosuppression tailored to match the higher risk status of thoracic transplant patients.

BK virus nephropathy in non‐renal solid organ transplant recipients: Are we looking hard enough?

“…Seven out of these eleven patients had diabetes mellitus that was being treated with medications. Our literature search revealed 24 previous reports of biopsy‐proven native BKV nephropathy in NRSOT patients bringing the total to 28 12‐35 Table 3 summarizes the renal outcome in these patients categorized by type of solid organ transplant. It can be seen that a majority of NRSOT patients with biopsy‐proven native kidney BKV nephropathy were reported to have developed CKD or ESRD.…”

“…Native kidney BKV associated disease in non‐renal solid organ transplant (NRSOT) recipients has been described in case reports and series over the years, but it has not been systematically studied 12‐35 . BKV nephropathy in the NRSOT recipient has the potential to lead to chronic kidney disease (CKD) or end‐stage renal disease (ESRD) with associated morbidity and mortality 36‐38 .…”

BK virus nephropathy in a heart transplant recipient

“…In addition, she presented a progressive increase in creatinine, initially attributed to toxicity by anticalcineurinics, but due to the poor response to the initial therapy, a renal biopsy was performed, and viral load was requested for BK virus, which was positive. These findings allowed the diagnosis of BK virus nephropathy, and due to the late diagnosis, the patient developed stage 4 chronic kidney disease 12,17,18 .…”

“…In other types of transplants, screening frequency has not yet been established. However, the systematic screening of viremia and BK viruria within post-transplant follow-up, especially in patients at high risk for this infection, may allow timely detection of the virus and an early modification of the immunosuppressive scheme to avoid chronic kidney damage 12 , 17 , 23 . In the case reported here, the treatment aimed to decrease immunosuppression by suspending the anticalcineurinic agent, which allowed to control the infection without rejection.…”

BK virus-associated nephropathy in a lung transplant patient: case report and literature review

“…Higher pre-transplant levels of neutralising anti-BKV antibodies may reduce the risk of BKVAN [ 10 ]. The rarity with which the disease affects native kidneys highlights unique characteristics of renal transplantation that engender a more permissible environment for reactivation; these include allograft injury from surgery and ischaemia, rejection, HLA mismatch impacting host immune activity in the allograft, and others [ 11 , 12 ].…”