A 56-year-old woman with sarcoidosis and acute renal failure

A Rare Case of Renal Sarcoidosis

Sarcoidosis is a multisystem granulomatous disorder characterized by non-caseating granulomas in multiple organs. It most commonly involves lungs and it is very rare to find isolated cases affecting other organ systems with no associated pulmonary findings. We hereby present a case of a young 30-year-old male who was referred to the hospital by his primary medical doctor due to right eye pain secondary to iritis and acute kidney injury (AKI). His initial laboratory studies revealed anemia, AKI, mild hypercalcemia, and the urinary analysis revealed proteinuria. Imaging studies were negative and a kidney biopsy was performed and showed results from the biopsy that revealed diffuse tubulointerstitial disease with early fibrosis, widespread moderate inflammation, multifocal tubulitis, and focal aggregate of epithelioid cells suggestive of granuloma consistent with sarcoidosis. The patient was treated with prednisone. Renal involvement of sarcoidosis is extremely rare (around 0.7%). It has a wide spectrum of presentation including abnormal calcium metabolism, nephrolithiasis, nephrocalcinosis, and acute tubulointerstitial nephritis with or without granulomas. This is a unique case as it shows renal sarcoidosis without coexisting pulmonary finding of hilar lymphadenopathy on chest X-ray. There are very few reported cases of renal sarcoidosis in the literature and this case can add to the pool of those cases. It also emphasizes the need for urgent renal biopsy in the settings of AKI associated with mild to moderate proteinuria. Lack of availability of comprehensive research on the disease may lead to misdiagnosis and delay in treatment.

A rare case of sarcoidosis causing granulomatous interstitial nephritis presenting as non oliguric acute renal failure in the Indian subcontinent

Sarcoidosis is a systemic disease characterized by non caseating granulomatous inflammation. Sarcoidosis can affect any organ, but it most commonly involves the lungs and lymph nodes. The exact incidence of renal involvement in sarcoidosis remains unclear, but it is found to be rare. Granulomatous interstitial nephritis is the most common histological pattern, but its presentation with renal insufficiency is rare. Here, we present a case of sarcoidosis causing granulomatous interstitial nephritis presenting as isolated non oliguric acute renal failure.

Acute Interstitial Nephritis: Etiology, Pathogenesis, Diagnosis, Treatment and Prognosis

Acute interstitial nephritis (AIN) is an important and common cause of acute kidney injury, particularly in hospitalized patients. The classic presentation of AIN includes fever, rash, arthralgias, eosinophilia, and acute kidney injury. While renal biopsy is considered the gold standard for diagnosis, the clinical presentation of fever and rash along with laboratory evidence of peripheral blood eosinophilia, eosinophiluria, and low-grade proteinuria strongly suggest the diagnosis. Histologically, interstitial inflammation with interstitial edema and tubulitis is the hallmark of interstitial nephritis. The most common causative factors are drugs, infections, and certain immune-mediated disorders. Discontinuation of the offending agent is considered the mainstay of therapy while the use of corticosteroids to hasten renal recovery may be beneficial. The role of interstitial nephritis in the pathogenesis of chronic kidney disease and end-stage renal disease is increasingly recognized, further emphasizing the importance of its early diagnosis and timely treatment.

Granulomatous interstitial nephritis in a renal allograft

We describe a middle-aged woman in whom granulomatous interstitial nephritis (GIN) developed in a renal allograft. She had undergone bowel resection due to an uncertain diagnosis of active granulomatous bowel disease 30 years earlier. Thereafter, frequent hyperoxaluria as well as calcium oxalate stone and recurrent urinary tract infections had resulted in a progressive deterioration in kidney function over a period of 20 years. She underwent living donor kidney transplantation; however, her kidney function progressively deteriorated, despite transplantation. A biopsy of the renal allograft revealed GIN with granulomatous vasculitis accompanied by calcium oxalate crystals. These as well as the laboratory findings indicated a diagnosis of sarcoidosis. We considered that the aggravated granulomatous inflammation on the allograft was caused by recurrent sarcoidosis accompanied by hyperoxaluria.

[Renal failure in sarcoidosis]

Renal sarcoidosis is rare and may lead to renal failure in less than 3% of patients. It may occur as a consequence of calcium metabolism disorders or granulomatous interstitial nephritis. In this retrospective study, we present five patients with renal failure secondary to sarcoidosis diagnosed in our centre on one period of nine years. Patients were three males and two females with a mean age at the time of the diagnosis of 31,6 years. Pulmonary involvement was present in three cases. Renal biopsy revealed granulomatous interstitial nephritis lesions in all patients. Extra-membranous glomerulonephritis was present in one case. In another case, moderate interstitial fibrosis was observed. Corticosteroid therapy using prednisolone 1mg/kg per day was used in all patients. Three patients had methylprednisolone pulse before oral corticosteroid therapy. One patient required several sessions of haemodialysis. All patients were followed up for a mean period of 52,6 months (ranged from 13 to 84 months). All patients improved their renal function with normalization of creatininemia in two of them. Renal involvement in sarcoidosis is probably underestimated. Corticosteroids therapy is efficient and must be introduced early to prevent progression to chronic renal failure.