Necrotizing crescentic glomerulonephritis related to sarcoidosis: a case report

Kidney manifestations of sarcoidosis

Renal involvement is a clinically relevant organ manifestation of sarcoidosis, leading to increased morbidity and complications. Although the exact incidence remains unknown, renal disease is likely to occur in up to one third of all sarcoidosis patients. Every patient with newly diagnosed sarcoidosis should receive a renal work-up and screening for disrupted calcium metabolism. Amid various forms of glomerulonephritis, granulomatous interstitial nephritis is the most common one, but it rarely leads to renal impairment. Histologically, granulomas can be absent. Nephrocalcinosis and nephrolithiasis are frequent forms when hypercalcaemia or hypercalciuria occur. Drugs used for treatment of systemic sarcoidosis can also cause renal damage. Due to its high heterogeneity, renal sarcoidosis can be difficult to treat. Glucocorticoids and various immunosuppressive treatments have been proven to be effective based on case series, but clinical trials are lacking. A treatment guideline for renal sarcoidosis is urgently needed. In this review article, we present an overview of the different forms of renal sarcoidosis and the diagnostic steps to confirm renal involvement; in addition, we provide insights on the management and available treatments. A better understanding regarding the pathogenesis of sarcoidosis is the key for the development of more specific, targeted therapies.

Systemic sarcoidosis presenting as a rare combination of interstitial nephritis with necrotizing vasculitis and urinary retention due to prostate involvement: a case report

BACKGROUND

Sarcoidosis affects multiple organs and exhibits diverse clinical manifestations. Although tubulointerstitial nephritis is a known feature of renal involvement, necrotizing vasculitis is rare. Furthermore, prostate involvement with urinary retention is unusual in patients with sarcoidosis. Here, we report a case of systemic sarcoidosis with a rare combination of manifestations and different acute kidney injuries.

CASE PRESENTATION

A 66-year-old man developed sudden urinary retention and fever. He was diagnosed with prostatitis and admitted to our hospital. An indwelling urethral catheter was inserted, and antimicrobial therapy was initiated; however, the prostatitis was refractory. Computed tomography revealed enlarged mediastinal lymph nodes. Analysis of transbronchoscopic lymph node and prostate biopsies showed epithelioid cell granulomas, suggesting systemic sarcoidosis. During the clinical course, the serum creatinine level rapidly increased to 2.36 mg/dL without oliguria. A kidney biopsy revealed tubulointerstitial injury with moderate lymphohistiocytic infiltration and small-vessel vasculitis in the interstitium. Following oral administration of 60 mg/day prednisolone, the patient's renal function immediately improved, and urinary retention did not recur.

CONCLUSIONS

To the best of our knowledge, this is the first reported case of sarcoidosis with two unusual complications. Given its clinical course and pathology, this case is clinically valuable.

Renal sarcoidosis

Sarcoidosis is a systemic inflammatory disease of unknown etiology. The pathogenesis rests on an aberrant T cell response to unidentified antigens in individuals predisposed by genetic and environmental factors. Increased expression of polarized macrophages and disequilibrium between effector and regulator T cells contribute to the formation of noncaseating granulomas, that are frequently found in affected organs. The main kidney abnormalities in sarcoidosis are granulomatous interstitial nephritis (GIN) and hypercalcemia-related disorders. The clinical diagnosis is difficult. The outcome is variable, ranging from spontaneous remission to end-stage kidney disease (ESKD). Early diagnosis and prompt treatment with corticosteroids can improve the prognosis. Hypercalcemia may be responsible for acute kidney injury (AKI) caused by vasoconstriction of afferent arterioles. Complications of persistent hypercalcemia include nephrocalcinosis and renal stones. In patients with ESKD, dialysis and transplantation can offer results comparable to those observed in patients with other causes of kidney failure. Based on a review of the literature, we present an overview of the etiopathogenesis, the renal manifestations of sarcoidosis and their complications, management and prognosis.

A case of systemic sarcoidosis with mesangial proliferative glomerulonephritis showing predominant deposition of IgG in the mesangial region

A 37-year-old African-British man was referred to our hospital for detailed examination because of persistent fever, swelling and pain in both ankle joints, and blurred vision for two months. Inguinal lymph node biopsy showed a large number of epithelioid granulomas without necrosis. Granulomatous anterior uveitis, nephropathy, high serum angiotensin-converting enzyme activity, and high serum-soluble interleukin-2 receptor were observed, and the diagnosis of systemic sarcoidosis was made. His serum creatinine was 1.4 mg/dL and hematuria, leukocyturia, and urine protein were also seen. The renal biopsy finding was mesangial proliferative glomerulonephritis, with no findings of granuloma formation or tubular interstitial nephritis. Immunofluorescence staining showed deposition of IgG, C3, and C1q in the mesangial region. IgG3 was dominant in subclass staining. There was no monoclonality on kappa and lambda staining. Electron microscopy showed predominant deposition in the mesangial region with some subepithelial and endothelial deposition. His hematuria and leukocyturia disappeared with steroid therapy, suggesting sarcoidosis-related nephropathy. A case of systemic sarcoidosis with mesangial proliferative glomerulonephritis showing predominant deposition of IgG in the mesangial region is presented. No cases of such histological findings have been reported so far, and it is necessary to analyze further cases to clarify the pathogenic significance of the renal biopsy findings observed in this case.

Role of the glucocorticoid receptor in glomerular disease

Glucocorticoids are potent anti-inflammatory agents that are commonly used in the treatment of various glomerular diseases. Data from in vitro and in vivo studies, in both animals and humans, convincingly demonstrate that glucocorticoids have many beneficial direct effects on glomeruli, including podocytes, suggesting that, in theory, systemic administration is not necessary to achieve therapeutic benefit. Indeed, it is increasingly recognized that systemic steroids often have an unfavorable risk-to-benefit ratio. As we move into an age of personalized medicine, strategies to develop targeted steroid delivery systems and individualized risk assessment algorithms are desirable in clinicians' efforts to "first, do no harm."

Renal sarcoidosis: approach to diagnosis and management

PURPOSE OF REVIEW

The purpose of this article is to provide understanding of renal sarcoidosis, the different types of renal sarcoidosis, disease burden of renal involvement, and treatment options.

RECENT FINDINGS

The frequency of renal involvement seems to be underestimated, but renal sarcoidosis represents a relevant group of organ manifestations and significantly adds to the patient's morbidity. Because histopathological analysis of renal biopsy specimens can reveal various entities, a diagnostic workup is necessary in every patient with sarcoidosis.

SUMMARY

If systematically screened for renal manifestations are likely to occur in up to 25-30% of all sarcoidosis patients. The most common histological form of renal sarcoidosis is the granulomatous interstitial nephritis; however, granulomas can be absent. Furthermore, one can find various forms of secondary glomerulonephritis. In cases with dysregulated calcium homeostasis, nephrocalcinosis and nephrolithiasis are commonly detectable kidney diseases. AA amyloidosis or renal masses because of granuloma formation are considered to be rare manifestations. In addition to glucocorticoids various immunosuppressive treatments such as tumor necrosis factor alpha inhibitors have proven to be effective based on case series.