P0282SARCOIDOSIS WITH RENAL INVOLVEMENT: APPROACH TO DIAGNOSIS AND MANAGEMENT

Abstract

Abstract Background and Aims Renal involvement in sarcoidosis is rare. It is most often the consequence of calcium metabolism disorders, interstitial granulomatous damage or secondary glomerular damage. It can progress to kidney failure in around 3% of cases. In this study, we determined the clinical presentation of sarcoidosis with renal involvement and we described the histological lesions. We report our experience about the management and the follow-up. Method we analyzed all cases of renal failure caused by sarcoidosis in our department during the period of 13 years (2006-2019). There were five patients (one man and four women) at the time of diagnosis. The middle age was 53.8 years. Results The renal involvement was revealing in 60% of the cases. The extrarenal localizations were: pulmonary (100%), cutaneous (knotty erythema 20%), ocular (dry eye syndrome (60%) and anterior uveitis (20%)), the reticuloendothelial system (adenitis (20%) and medullary (20%)), exocrine glands (sialadenitis (40%), nasal (20%), nervous (optic neuritis 20%)). The middle renal clearance (eGFR) at the time of diagnosis of renal involvement was 33ml / min / 1.73 m. Moderate proteinuria was observed in four patients (median: 0.99 g / 24 hours), aseptic leukocyturia in one patient. No patient had microscopic hematuria. Hypercalcemia was noted in 60% of patients with hyper calciuria (median: 3 mmol / kg / 24 hours). Nephrolithiasis was noted in only one patient. No cases of nephrocalcinosis was noted. Renal biopsy showed tubulointerstitial nephropathy with granulomatous in 2 cases (40%), absence of granuloma in one case, extra-membranous glomerulonephritis in one patient and moderate interstitial fibrosis with tubular atrophy in two patients, fibrous andarteritis in a single case. A granuloma without caseous necrosis was objectified on the osteo-medullary biopsy in a single case. All patients received oral corticosteroids (Prednisone: 1 mg / kg / day for 4 patients; 0.5 mg / kg / day for one patient) associated with the treatment of hypercalcemia (hydration and diuretics). The follow-up varied from 2 to 156 months with an median of 56.4 months. 3 patients improved their renal function with a middle clearance : M0: 29 ml / min, M1: 42 ml / min, M3: 68 ml / min, M6: 67 ml / min, M12: 95 ml / min. A non-recovery of renal function was noted in only one patient. An end-stage renal disease was observed in two patients. A renal and extrarenal (lymph node) relapse was noted in a single patient with an interval of 7 years after the initial presentation. Conclusion Renal involvement in sarcoidosis is probably underestimated. Treatment is based on corticosteroid, which must be introduced early to prevent progression to renal failure.