#2663 KIDNEY INVOLVEMENT IN MYELODYSPLASTIC SYNDROMES

Abstract Background and Aims Myelodysplastic syndromes (MDS) are hematologic disorders characterized by ineffective and dysplastic hematopoiesis that can be associated with systemic inflammatory and autoimmune diseases. The objective of this study was to describe kidney involvement in MDS patients, their treatments, and outcomes. Method We conducted a French and American multicenter retrospective observational study in nine centers, identifying MDS patients with acute kidney injury (AKI), chronic kidney disease (CKD), and urine abnormalities. Results Seventeen patients (males n = 11, median age 76 [70-79]) developed a kidney disease 6 months [0-31] after the diagnosis of MDS. Median urinary protein to creatinine ratio was 1.9g/g [0.8-3.3], and median serum creatinine was 3.5mg/dL [1.5-4.7]. Twelve patients (70%) had AKI at presentation, and 14 (82%) extra-renal symptoms, which consisted mostly in cutaneous and pneumological manifestations. The renal diagnoses included antineutrophilic cytoplasmic antibody (ANCA) associated vasculitis (AAV) (n = 8, 47%), ANCA negative vasculitis (n = 4, 24%), C3 glomerulonephritis (n = 2), immune complex-mediated glomerulonephritis (n = 1), polyarteritis nodosa (n = 1), and IgA vasculitis (n = 1). Kidney biopsies were performed in 10 of the cases. All patients, except one, received a treatment following the MDS-associated kidney injury (n = 16, 94% with steroids). The effect of MDS treatment on kidney injury could be assessed in 8 patients treated with azacitidine, and renal function evolution was heterogenous. After a median follow-up of 9 months [4.1-14.2], 4 patients had CKD stage 3, 4 CKD stage 4, 5 an end stage kidney disease. Three patients evolved to an acute myeloid leukemia (AML), and 3 died. Compared to 84 MDS controls, patients who had a kidney involvement were younger (p = 0.03), had a higher number of dysplasia lineages (3 lineages, p = 0.001), and were more eligible to receive hypomethylating agents (p = 0.031), but no survival difference was seen between the two groups (p = 0.5227). Compared to 265 AAV without MDS, MDS-associated AAV were older (p = 0.019), ANCA serology was more frequently negative (p = 0.014), and more cutaneous lesions were seen (p = 0.003). Conclusion The spectrum of kidney injuries associated with MDS is mostly represented by vasculitis, and especially AAV. A diagnosis of ANCA vasculitis in an elderly patient, or with a cutaneous manifestation, or without ANCA positivity, should lead to the search for a possible MDS.