Diffuse parenchymal form of malakoplakia in renal transplant recipient: a case report

Malakoplakia is an unusual chronic inflammatory disease related to prior urinary tract infection. It is characterized by the presence of macrophages with foamy cytoplasm exhibiting larger PAS positive inclusions that stain for calcium and iron. Malakoplakia affects renal allograft and is associated with severe morbidity. Herein, the authors report a new case of renal graft malakoplakia in a 23-year-old female patient. The patient received a living-related donor renal transplantation with a high immunological risk. Plasmapheresis and intravenous immunoglobulin (i.v. Ig) treatment, pre- and post-transplant, and induction with rabbit anti-thymocyte globulins were used due to presence of donor specific antibodies and positive B cross match by flow cytometry. The patient had an early urinary tract infection with a good outcome. On Day 36 post-transplant (PO), the patient returned to the clinic with fever, graft pain and acute renal dysfunction leading to hemodialysis. Escherichia coli (E. coli) was present in the blood and urine culture. At the time, the renal biopsy revealed numerous sheets of macrophages with foamy, eosinophilic cytoplasm showing several PAS positive granules and large inclusions that stained strongly with hematoxylin, calcium (von Kossa method) and iron (Prussian blue). The patient was diagnosed with malakoplakia related to a kidney transplant. Despite prolonged treatment with antibiotics, determined by a susceptibility test, the patient did not recover renal function and remained on dialysis.