Nephrotoxicity of calcineurin inhibitors as a risk factor for BK polyomavirus replication after kidney transplantation.

BK polyomavirus-associated nephropathy (PyVAN) is responsible for a significant percentage of transplanted kidneys prematurely terminating their function. Its occurrence is closely related to the intensity of immunosuppressive therapy. In a group of 161 newly transplanted patients, we prospectively evaluated 457 protocol renal biopsies performed within the first year after transplantation. Using the calcineurin inhibitors (CI) nephrotoxicity score, the incidence of nephrotoxicity was monitored as a manifestation of excessive immunosuppression. Findings were correlated with clinical evidence of active BK polyomavirus (BKPyV) replication and PyVAN. Compared to the normal histology, nephrotoxicity was associated with more frequent BKPyV viremia and viruria (p = .01 and p < .01, respectively) and more common occurrence of PyVAN. The persistence of toxicity in the subsequent biopsy proved to be a negative risk factor of viremia and viruria (p = .03 and p < .01, respectively), independently of the initial BKPyV status. Toxicity could also be used as a predictor of viremia and viruria (p = .04 and p < .01, respectively) even in the absence of viral replication at the time of initial biopsy. The early histological manifestation of CI nephrotoxicity was associated with significant BKPyV reactivation in the risky first posttransplant year.

BK virus-induced renal allograft nephropathy.

BK virus nephropathy (BKVN) is a serious opportunistic infection threatening renal function especially during the first year after transplantation. Its incidence is now on the rise and is closely related to the level of the recipient's immune system inhibition. This is more intensive with current trends in transplantation medicine, where more potent immunosuppressive protocols are used and more aggressive antirejection therapy is applied. In the absence of BK virus (BKV) specific therapy and limited treatment options for advanced BKVN, active screening of BKV replication and subsequent preemptive adjustment of immunosuppression are essential measures to prevent BKVN. However, it remains unclear how to modify immunosuppressive protocols as well as how to address initial stages of BKV replication. This comprehensive review summarizes the currently applied and not completely uniform procedures for the detection, prophylaxis and therapy of BKV replication and BKVN. The pitfalls brought by reduced immunosuppression, as a typical response to a significant viral replication or a developed BKVN, are also mentioned, particularly in the form of graft rejection. The paper also outlines the authors' experiences, and lists currently ongoing studies on the subject. The perspectives of new, especially immune-based, procedures in the treatment of complications associated with BKV infections are highlighted. Different views on the management of patients indicated for kidney re-transplantation whose previous graft failed because of BKVN are also discussed.

Late Rupture of Lumbar Artery as an Unusual Complication after Renal Biopsy - Case Report.

The most serious complication of renal biopsy is vascular damage with subsequent haemorrhage. To our knowledge, we present a first ever case of lumbar artery (LA) rupture accompanied by massive retroperitoneal bleeding, which developed after a significant amount of time following the biopsy itself. In a 63-year-old Caucasian female patient, a percutaneous left kidney biopsy was performed under continuous ultrasound guidance. On the fourteenth day after the procedure, she was examined for a sudden onset of left lumbar region pain. Computed tomography angiography showed a large retroperitoneal hematoma with active bleeding from the fourth left LA. Successful endovascular superselective embolization was performed immediately. The predisposing factor for the late haemorrhage could have been anticoagulation therapy, renal insufficiency and older age. Our case report highlights the need for caution, especially when performing kidney biopsy in a group of high-risk patients, particularly if they are indicated for subsequent anticoagulant therapy.

Cutaneous bacillary angiomatosis due to Bartonella quintana in a renal transplant recipient.

Bacillary angiomatosis (BA) is a disorder of neovascular proliferation involving skin and other organs of immunosuppressed patients caused by Bartonella species. BA has been recognized in both immunocompetent and immunodeficient patients, mostly in human immunodeficiency virus (HIV)-infected persons, much more rare in those with other immunodeficiencies, including organ transplantation. Diagnosis is based on serologic analysis, culture and molecular biology [detection of Bartonella species deoxyribonucleic acid (DNA) in tissue biopsy extracts by real-time polymerase chain reaction (PCR)]. All immunosuppressed patients with BA should be treated with antibiotics because of potentially life-threatening course of the disease. We report the first case of cutaneous bacillary angiomatosis due to Bartonella quintana in renal transplant recipient. This presentation demonstrates that BA should be considered a differential diagnosis in immunocompromised patients presenting with fever and cutaneous angioma-like lesions.