Focal Segmental Glomerulosclerosis Associated with Idiopathic Myelofibrosis

A Case of Myeloproliferative Neoplasm-Related Glomerulopathy Secondary to Primary Myelofibrosis With Acute Leukaemic Transformation

Glomerular diseases associated with myeloproliferative neoplasms (MPN) are rare, and most often present with proteinuria and kidney impairment. Its natural history is not well described, although it has been associated with poor prognosis in described cases. Here, we present a case of MPN-related focal segmental glomerulosclerosis (FSGS) secondary to primary myelofibrosis (PMF) and describe its progression with transformation of PMF to leukaemia. A 52-year-old gentleman was referred for lower limb swelling on a background of primary myelofibrosis requiring splenectomy 3 months prior. Kidney function was normal, but there was nephrotic-range proteinuria of 3.6 g (normal range, NR < 0.15 g) and mild hypoalbuminaemia of 29 g/L (NR 33-48 g/L). Urine microscopy was bland with no haematuria or pyuria. A kidney biopsy confirmed secondary FSGS with dysmorphic megakaryocytes in the glomerular capillaries, as well as immunohistochemistry demonstrating the presence of megakaryocytes and erythroid precursors in the interstitium, indicating the presence of extramedullary haematopoiesis. No deposits were seen on immunofluorescence or electron microscopy. Despite an initial response to high-dose corticosteroids, a relapse in proteinuria to 10.9 g was seen 5 months after diagnosis. This coincided with leukaemic transformation, which was confirmed on bone marrow biopsy. We describe a case of FSGS secondary to PMF presenting with normal kidney function and nephrotic syndrome. As far as the authors are aware, this is the first case to detail the progression of kidney disease before and after leukaemic transformation. Ongoing follow-up may provide useful insights into the natural history of this infrequent association.

Myeloproliferative Neoplasm and Myelodysplastic Syndrome-Associated Renal Disease: A Histopathological Report of Two Cases

Myeloproliferative neoplasms (MPN) are clonal disorders of hematopoietic stem cells with a proliferation of one or more myeloid lineage and mature cell overproduction, while myelodysplastic syndrome (MDS)/MPN simultaneously show aspects of MDS and MPN, leading to partially ineffective hematopoiesis with associated dysplastic changes. This spectrum of disorders includes chronic myeloid leukemia, polycythemia vera, primary myelofibrosis, and essential thrombocythemia. MDS/MPN are classically not associated with renal complications; however, an accumulating body of evidence suggests that multiple growth factors, cytokines, endothelial damage, and an activated complement system in these patients can induce glomerulopathy, as nearly a third of these patients present with advanced renal disease on diagnosis, which is unlikely to be age or hypertension-related. In this report, we present two cases of patients with MPN/MDS, a 45-year-old male with essential thrombocythemia and a 73-year-old male with polycythemia vera, both of whom developed generalized edema and were referred to our institution from their outpatient nephrologists due to accompanying proteinuria. Renal biopsy of the first patient revealed mesangiocapillary and mesangioproliferative MPN-associated glomerulopathy. In contrast, the second patient was diagnosed with MPN/MDS-associated segmental mesangial proliferative glomerulonephritis and renal vasculature drug toxicity. Both patients were started on treatment - corticosteroid as per consensus.

Renal disease associated with myeloproliferative neoplasms and myelodysplastic syndrome/myeloproliferative neoplasms

AIMS

Renal changes in patients with myeloproliferative neoplasms (MPNs) or myelodysplastic syndrome (MDS)/MPNs have been addressed by few, respectively no, reports. The aim of this study was to focus on a systematic evaluation of renal biopsies in patients with MPNs or MDS/MPNs.

METHODS AND RESULTS

The cohort comprised 29 patients (23 men) aged 67 ± 11 years (mean ± standard deviation), diagnosed with chronic myeloid leukaemia (n = 5), polycythaemia vera (n = 9), primary myelofibrosis (n = 5), essential thrombocythaemia (n = 2), or chronic myelomonocytic leukaemia (n = 4), as well as MPNs or MDS/MPNs not otherwise specified (n = 4). Patients manifested with proteinuria (93%), partially in the nephrotic range (46%), haematuria (72%), and impaired kidney function (93%). The most prominent histological findings included double-contoured glomerular basement membranes (71%), acute endothelial damage (68%), intracapillary platelet aggregation (62%), mesangiolysis (21%), thrombotic microangiopathy (24%), segmental glomerulosclerosis (66%), mesangial hypercellularity and sclerosis, extramedullary haematopoiesis (17%), and also IgA nephropathy (21%) and glomerulonephritis (GN) with features of infection-related GN (21%). MPN and MDS/MPN patients showed significantly more chronic changes than age-matched and sex-matched controls, including global and segmental glomerulosclerosis, mesangial sclerosis, and hypercellularity, whereas the extent of arteriosclerosis was comparable.

CONCLUSIONS

MPN and MDS/MPN patients show glomerular scarring that exceeds age-related phenomena. Ongoing endothelial damage, growth factors released by platelets and deposition of immune complexes are probably the causative mechanisms. Early recognition of renal failure heralded by proteinuria and haematuria, and consequent control of risk factors for kidney failure, should be recommended for MPN and MDS/MPN patients.

Focal segmental glomerulosclerosis in a patient with prefibrotic primary myelofibrosis

We report a case of 56-year-old man presented to us with chief complaints of frothy urine and leg swelling. A urinalysis revealed nephrotic-range proteinuria. Haematological investigations revealed thrombocytosis, leucocytosis and peripheral blood smear showed a leucoerythroblastic picture. JAK 2 mutation was positive. To confirm the diagnosis of myeloproliferative neoplasm, bone marrow biopsy was done, which was suggestive of primary myelofibrosis. The patient underwent kidney biopsy due to rapidly declining renal function and persistent proteinuria, which was suggestive of focal segmental glomerulosclerosis. Early glomerulopathy is rare in myeloproliferative neoplasm, and aggressive follow-up is required to prevent progression of kidney disease.

WITHDRAWN: Nephrotic syndrome in primary myelofibrosis with renal extramedullary hematopoiesis and glomerulopathy in the JAK inhibitor era

Ahead of Print article withdrawn by publisher. The publisher apologizes for any inconvenience this has caused. The article was scheduled for the journal "Clinical Nephrology. Case Studies" (issn 2196-5293). The article is available in PubmedCentral: https://www.ncbi.nlm.nih.gov/pubmed/29350220 
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Myeloproliferative neoplasms cause glomerulopathy

Myeloproliferative neoplasms are clonal hematopoietic stem cell disorders that can produce an undefined glomerulopathy. To better characterize the glomerular disease associated with myeloproliferative neoplasms, we evaluated features of 11 patients with myeloproliferative neoplasm-related glomerulopathy that included 8 patients with primary myelofibrosis, and 1 each with chronic myelogenous leukemia, polycythemia vera, and essential thrombocythemia. Indications for biopsy were nephrotic-range proteinuria (nephrotic syndrome in four) and chronic renal insufficiency. The mean time from diagnosis of the neoplasms to biopsy was 7.2 years. Histologically, mesangial sclerosis and hypercellularity were seen in all 11 cases, segmental sclerosis in 8, features of chronic thrombotic microangiopathy in 9, and intracapillary hematopoietic cells in 4. On follow-up, seven patients had persistent renal dysfunction and four progressed to end-stage renal disease (ESRD). Thus, glomerulopathy appears to be a late complication of myeloproliferative neoplasms, particularly primary myelofibrosis, with guarded prognosis. Greater awareness of this entity and larger studies are needed to define possible therapies.

Pathogenesis, diagnosis and management of paraneoplastic glomerulonephritis

Paraneoplastic glomerulonephritis is a rare complication of malignancy that is frequently mistaken for idiopathic glomerulonephritis. Failure to recognize paraneoplastic glomerulonephritis can subject patients to ineffective and potentially harmful therapy. The pathology of paraneoplastic glomerulonephritis varies between different types of malignancies. This Review discusses the association of glomerulonephritis with both solid tumors and hematological malignancies. The pathogenetic mechanisms of many glomerular lesions seem to relate to altered immune responses in the presence of a malignancy. Studies in the Buffalo/Mna rat model of spontaneous thymoma and nephrotic syndrome indicate that polarization of the immune response toward a T-helper-2 (T(H)2) profile has an important role in the development of thymoma-associated glomerular lesions. Furthermore, overexpression of the T(H)2 cytokine interleukin 13 in rats induces minimal change disease. Such findings from experimental studies might facilitate the identification of biomarkers that can distinguish paraneoplastic glomerulonephritis from idiopathic and other secondary glomerulonephritides. This Review describes potential pathogenetic mechanisms for paraneoplastic glomerulonephritides associated with different malignancies and highlights the need for a multidisciplinary approach to the management of patients with paraneoplastic glomerulonephritis.