[Encrusted Pyelitis during a case of Thrombotic Thrombocytopenic Purpura]

Encrusted pyelitis is a chronic urinary tract infection associated with mucosal encrustation induced by urea splitting bacteria. More than 40 bacteria have been implicated but the most frequent is Corynebacterium group D2. Predisposing factors are debilitating chronic diseases and preexisting urological procedures. Immunosoppression is an important cofactor. For these reasons the disease is almost always nosocomially acquired and renal transplant recipients are at particular risk. The symptoms are not specific and long lasting: dysuria, flank pain and gross haematuria are the most frequent; fever is present in two-thirds. The demonstration of urine splitting bacteria in constantly alkaline urines and radiological evidence of extensive calcification of pelvicalyceal system, ureter and bladder at US or CT scan in a clinical context of predisposing factors are the mainstay of diagnosis. Treatment is based on adapted antibiotic therapy, acidification of urine and excision of plaques of calcified encrustation. The prognosis relies on timing of diagnosis; delay can be detrimental and result in patient's death and graft loss. We describe a unique case of 69-year-old man with two contemporary diseases: autoimmune thrombotic thrombocytopenic purpura and encrusted pyelitis with a fatal evolution.