Renal sarcoidosis: clinical, laboratory, and histologic presentation and outcome in 47 patients

[Kidney involvement in sarcoidosis]

Sarcoidosis is a chronic multisystemic inflammatory disorder of unknown etiology, characterized by the presence of non-necrotizing epithelioid and giant cell granulomas. Various renal manifestations have been reported in patients with sarcoidosis. Disorders of bone and mineral metabolism related to the overexpression of 25-hydroxyvitamin-D1α-hydroxylase by alveolar and granuloma macrophages are frequently associated with sarcoidosis. Hypercalcemia and hypercalciuria are a major cause of renal injury predisposing to pre renal azotemia, acute tubular necrosis, nephrolithiasis and nephrocalcinosis. Therapeutic management of hypercalcemia includes preventive measures (limited sunlight exposure, limited vitamin D and calcium intakes, and adequate hydration) and specific treatment in cases of severe hypercalcemia (corticosteroid therapy, chloroquine or ketoconazole). Granulomatous tubulointerstitial nephritis is the most common renal lesion associated with sarcoidosis leading to end stage renal disease in some patients. In these cases, interstitial fibrosis seems to appear early in the course of sarcoidosis and is a major prognostic factor requiring rapid corticosteroid therapy to reduce the risk of severe renal impairment. Membranous nephropathy seems to be the most frequent glomerular disease that may occur in association with sarcoidosis. Among kidney allograft recipients, the risk of recurrence of granulomatous tubulointerstitial nephritis is high and may have a negative impact on the graft survival.

Renal sarcoid: Pseudotumoral radiologic manifestations and pathologic correlation

Sarcoidosis has a wide variety of radiologic manifestations. However, lesions that mimic tumors are rare presentations of this systemic disorder. Differentiating sarcoid granulomas from malignancy is critical, as management and prognosis for these two entities are drastically different. Therefore, it is imperative to be cognizant of the various radiologic appearances of pseudotumoral renal sarcoid. We report a case of a 61-year-old man with recently diagnosed prostate cancer and pulmonary sarcoidosis discovered on staging CT who presented with pseudotumoral renal sarcoid mimicking malignancy.

[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.

Diagnostic utility of kidney biopsy in patients with sarcoidosis and acute kidney injury

BACKGROUND

Sarcoidosis is an idiopathic multisystem disease characterized by noncaseating granulomatous inflammation. Renal biopsy is often performed to evaluate the patient with sarcoidosis and acute kidney injury (AKI). Diagnosis rests on the demonstration of noncaseating granulomas and exclusion of other causes of granulomatous inflammation. This paper reports a patient with pulmonary sarcoidosis and AKI whose renal function improved after prednisone therapy despite the absence of kidney biopsy findings characteristic of sarcoidosis.

CASE REPORT

A 63-year-old Caucasian male with history of hypertension was treated for pulmonary sarcoidosis with a 6-month course of prednisone. His creatinine was 1.6 mg/dL during the course. Two months after finishing treatment, he presented with creatinine of 4 mg/dL. A kidney biopsy was performed, which showed nonspecific changes without evidence of granuloma or active interstitial inflammation. He was empirically started on prednisone for presumed renal sarcoidosis, even with a nondiagnostic kidney biopsy finding. Within a month of treatment, his serum creatinine improved to 2 mg/dL, though not to baseline. He continues to be stable on low-dose prednisone. With this case as a background, we aimed to determine the incidence of inconclusive kidney biopsies in patients with sarcoidosis presenting with AKI and to identify the various histological findings seen in this group of patients.

METHODS

In this retrospective study, all patients who had native renal biopsies read at The Ohio State University over the period of 6 years were identified. Those patients with a diagnosis of sarcoidosis, presenting with AKI, were included for further review.

RESULTS

Out of 21 kidney biopsies done in patients with sarcoidosis over a period of 6 years, only four (19%) showed granulomatous interstitial nephritis (GIN). An equal number of patients (4 [19%]) had presence of membranous nephropathy. Nephrocalcinosis was seen in three patients (14%). Almost half of the biopsies had findings suggestive of diabetic nephropathy or other nonspecific changes not characteristic of renal sarcoidosis (48%).

CONCLUSION

Renal sarcoidosis can be focal in nature and characteristic lesions can be missed in a small-needle core biopsy. Inconclusive renal biopsies with only nonspecific findings are frequent in patients with sarcoidosis and AKI. The presence of GIN on renal biopsy, although classic, is uncommon. Renal sarcoidosis remains a presumptive clinical diagnosis and empiric treatment with steroids may be initiated in cases with a strong clinical suspicion even in the absence of characteristic renal biopsy findings.

A case of sarcoidosis developing as sarcoid myopathy concomitant with systemic sclerosis and review of the literature

A 65-year-old man was diagnosed with systemic sclerosis on the basis of skin thickening and positivity of anti-Scl-70 antibodies. Because myogenic enzymes, such as creatinine phosphokinase and aldorase, were also elevated, myopathy or myositis associated with systemic sclerosis was considered. Muscle magnetic resonance imaging and gallium scintigraphy did not show abnormalities. Findings of muscle biopsy demonstrated presence of noncaseating granulomas with multinucleated giant cells. In addition, serum angiotensin-converting enzyme and lysozyme were elevated, and therefore a diagnosis of sarcoid myopathy was made. Further, renal sarcoidosis was revealed with renal biopsy. Prednisolone (40 mg/day) improved both the myopathy and nephritis. Sarcoid myopathy is a rare condition, but it should be considered when myogenic enzymes are elevated in the patient with systemic sclerosis. Further, muscle biopsy may be essential to make an accurate diagnosis in such condition.

Progressive renal insufficiency, hypercalcaemia, bicytopaenia and a history of breast cancer

Sarcoidosis can affect all organs and may mimic a variety of other diseases. In the absence of typical pulmonary features, extrapulmonary manifestations may be difficult to diagnose. We describe here the very uncommon case of a patient with mild pulmonal involvement but distinct renal, bone marrow and lymph node sarcoidosis. Treatment with glucocorticoids significantly improved kidney function and normalized serum calcium levels as well as the blood count. This case underscores the importance of sarcoidosis to be considered as a differential diagnosis of renal failure associated with hypercalcaemia and nephrocalcinosis. Bone marrow involvement should always be suspected if mono-, bi- or pancytopaenia coexist.

Drug-induced granulomatous interstitial nephritis in a patient with ankylosing spondylitis during therapy with adalimumab

Tumor necrosis factor α (TNF-α) inhibitors are used in the treatment of rheumatoid arthritis, psoriasis, psoriatic arthritis, Crohn disease, ankylosing spondylitis, and juvenile idiopathic arthritis. Use of TNF inhibitors is associated with the induction of autoimmunity (systemic lupus erythematosus, vasculitis, psoriasis, and sarcoidosis/sarcoid-like granulomas). We report a case of interstitial granulomatous nephritis in a patient with ankylosing spondylitis after 18 months of treatment with adalimumab. Previously reported cases of sarcoid-like reactions secondary to the use of TNF-α inhibitors involved the liver, lung, lymph nodes, central nervous system, and skin. Granulomatous nephritis after adalimumab treatment has not been described. Close observation of patients undergoing treatment with TNF inhibitors for evolving signs and symptoms of autoimmunity is required. Organ involvement is unpredictable, which makes correct diagnosis and management extremely challenging.

Renal transplantation in patients with sarcoidosis: a French multicenter study

BACKGROUND AND OBJECTIVES

Sarcoidosis is a multisystem disorder of unknown etiology. The outcome of renal transplantation on patients with sarcoidosis is not well known. A few case reports have described recurrence of sarcoidosis after transplant. Here, we report for the first time results and outcome of renal transplantation in a series of patients with sarcoidosis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Eighteen patients with sarcoidosis who underwent renal transplantation were identified retrospectively in eight French renal transplantation departments. Patient medical charts, demographics, and the outcome of renal transplantation were reviewed.

RESULTS

Initial renal disease was related to sarcoidosis in 10 patients. At the end of the follow-up (median, 42 months), patient and death-censored graft survival were 94.4% and the mean GFR was 60 ml/min per 1.73 m(2). Five patients (27%) experienced recurrence of sarcoidosis including extra-renal involvement in two patients and renal involvement in three patients. Median GFR was lower in the group of patients with renal recurrence compared with that of the entire cohort: 31 ml/min per 1.73 m(2). Recurrence occurred shortly after transplantation (median period, 13 months). Risk factors for recurrence included primary renal disease related to sarcoidosis and a shorter delay between the last episode of sarcoidosis and renal transplantation.

CONCLUSIONS

Our results indicate that renal transplantation may be carried out safely in transplant candidates with sarcoidosis. Recurrence is not rare and is likely to affect graft outcome. These results fully justify a specific clinical and histologic monitoring mainly during the early posttransplant period.

Calcium and vitamin D in sarcoidosis: how to assess and manage

The synthesis of vitamin D is altered by the granulomatous inflammation of sarcoidosis leading to increased production of 1, 25-dihydroxyvitamin D. Mounting evidence suggests that vitamin D is an immunomodulating hormone that inhibits both antigen presentation by cells of the innate immune system, and the cytokine release and proliferation of Th1 cells. These and other extraskeletal health benefits have led to an increase in vitamin D assessment and pharmacological supplementation in the general population. This review highlights the altered synthesis and general immunomodulating properties of vitamin D with a special emphasis on known interactions with sarcoidosis. In addition, the assessment of vitamin D nutritional status, its pharmacological supplementation, and the management of bone health in patients with sarcoidosis are reviewed.

[Granulomatous interstitial nephritis: A retrospective study of 44 cases]

PURPOSE

Granulomatous interstitial nephritis (GIN) are identified in 0.5 to 1,3% of all renal biopsies. Renal outcome and treatment modalities are not clearly established in the literature.

METHODS

We retrospectively analyzed a case series of 44 GIN identified among all renal biopsies performed between 1984 and 2005 in the Rhône-Alpes area.

RESULTS

The study population included 25 men and 19 women with a mean age of 56 years, and mean diagnostic delay was 11 months. Renal function was severely impaired (mean creatinine clearance 24mL/min). Proteinuria was observed in 77% (mean value 0,9 g/24h) of the patients and associated with microscopic hematuria and leukocyturia in 30% and 25%, respectively. The most common diagnosis was sarcoidosis (25%, n = 11), followed by drug-induced GIN (9%, n = 4), tuberculosis (6,8%, n=3), hemopathy-related paraneoplastic GIN (6,8%, n = 3), HIV infection (n = 1) and chronic renal allograft rejection (n = 1). In other patients, no aetiology was found (48%, n = 21). Severity of renal failure justified hemodialysis in 34% (n = 15) of the patients. Three patients underwent renal transplantation. Nonetheless, renal outcome was generally favorable: renal function improved in 41% (n = 18) and stabilized in 34% (n = 15) of patients.

CONCLUSIONS

Sarcoidosis, drug-induced and infections represent the main causes of GIN. Histologic features are not specific enough to determine the aetiology. Corticosteroids is the gold standard in sarcoidosis, drug-induced, and idiopathic GIN. Treatment is etiologic in the other cases.