Primary myelofibrosis associated glomerulopathy: significant improvement after therapy with ruxolitinib

Primary myelofibrosis (PMF) is a type of myeloproliferative neoplasm (MPN) characterized by the predominant proliferation of megakaryocytes and granulocytes in the bone marrow, leading to the deposition of fibrous tissue, and by a propensity toward extramedullary hematopoiesis. Renal involvement in PMF is rare, but kidney tissue samples from these patients reveal MPN-related glomerulopathy, a recently discovered condition, in the late stages of the disease. We present the first case described in the medical literature of a patient with early renal glomerular involvement in PMF/MPN. A 60-year-old man with stage 4 chronic kidney disease and a recent diagnosis of PMF (within 4 weeks of presentation at our renal division) presented with generalized body swelling, acute kidney injury, and massive nephrotic-range proteinuria. Kidney biopsy was performed to determine the etiology of the patient's renal dysfunction and revealed early renal glomerular involvement that was histologically characteristic of MPN-related glomerulopathy. Early diagnosis and prompt medical management returned the patient's kidney functionality to the levels seen on initial presentation at our hospital. Large studies with long follow-up durations are necessary to identify and categorize the risk factors for the development of MPN-related glomerulopathy, to standardize therapeutic regimens, and to determine whether aggressive management of the myelofibrosis slows the progression of kidney disease.