BK virus (BKV)-hemorrhagic cystitis (HC) is a well-known complication of hematopoietic stem cell transplantation (HSCT), and contributes to significant morbidity. We report on and discuss the management of a patient with BK viremia, whose post-HSCT course was complicated by severe BKV-HC, combined with grade IV skin and gut graft vs host disease (GVHD).

A 15 year-old boy diagnosed with leukemia underwent an HSCT with his mother as the haploidentical donor. Graft source was bone marrow, with TNC/kg 4.4 × 10*8/kg. Neutrophil engraftment was achieved at day +16; chimerism demonstrated 100% donor cells. Myeloablative conditioning consisted of cclophosphamide (Cy) 50 mg/kg x 2 days (days -5 to -4) and total body irradiation 12 Gy on days -3 to -1. GVHD prophylaxis consisted of post-transplant Cy on days +3 and + 4 along with mycophenolate mofetil x 30 days and cyclosporin. His transplant course was complicated by cytomegalovirus (CMV) infection and grade II skin GVHD. He was discharged on day +20 and readmitted on day +39 with grade IV skin GVHD and transferred to the intensive care unit. Immunosuppressive medications (Ruxolitinib with IV methylprednisolone) were started, and his symptoms started to improve. However, he developed severe lower urinary tract symptoms and hematuria with frequent passage of clots on Day +65. A diagnosis of grade III hemorrhagic cystitis (HC) was made. Quantitative PCR from serum (600 copies/mL) as well as from urine came positive for BK polyomavirus, Cidofovir was started and immunosuppression reduced. Continuous bladder irrigation was initiated without significant improvement. On day +86, a cystoscopy was done for clot evacuation. As he was unstable on day+105 a transvesical catheterization was performed, with opening of the bladder, matured to the skin, with compression of the mucosa by surgical compresses for bleeding control, which was removed after 48 hours. D+113 persisted with active bleeding, requiring re-approach, and a 3 way Foley catheter was inserted. He received daily hyperbaric sessions for 2 months. Progressive improvement of hematuria was seen, and a bladder ultrasound was performed for control, on day+123, with a slightly distended bladder, without signs of bleeding. On day+147, the cystostomy was closed and no new episodes of bleeding occurred. The patient was discharged from the ICU after 4 months, and all viral PCRs were negative, chronic GVHD was well controlled with reduced immunosuppression and absence of hematuria. Patient is alive with sustained donor engraftment and excellent hematopoietic function at 10 months post-HSCT.

Treatment of BKV associated HC is currently controversial. This case highlights the importance of balancing immunosuppression and infection treatment post-HSCT. It must be emphasized that at present no standard guidelines are drafted regarding treatment of BK virus related HC.