Parvovirus B19 in kidney transplantation: key points and essential pitfalls to know.

Parvovirus B19 infection is s new viral threat in post-kidney transplantation. It is a viral infection often acquired from the donor, occurring in young transplant patients during the first post-kidney transplantation months, and with a non-specific clinico-biological picture. The hallmark symptom is regenerative anaemia which may be severe, requiring blood transfusion. The C3 and C4 complement fractions are reduced and constitute an early and inexpensive diagnostic marker. Diagnosis is often delayed due to the non-specific clinico-biological picture. However, severe anaemia and hypocomplementemia are early and suggestive signs of parvovirus B19 infection. Levels of parvovirus B19 DNA, as determined by real time-polymerase chain reaction (RT-PCR), are often very high and tend to decrease slowly over several months. Treatment is based on adaptive reduction of immunosuppression, adequate in the forms with few symptoms, discontinuation of antiproliferative agents, or a switch to other molecules associated with intravenous immunoglobulins in the severe and highly symptomatic forms. Screening for other concomitant viral infections, particularly for cytomegalovirus, Epstein Barr virus, and BK virus is systematic. Relapses are quite frequent during the first-year post-transplantation. Clinical-biological follow-up aims to detect any recurrence of the parvovirus B19 infection, the occurrence of parvovirus B19-related glomerulopathy, and acute rejection. Parvovirus B19 infection is a new viral threat in post-kidney transplantation and requires broader and/or randomised studies to better establish the diagnostic and therapeutic approach.