Granulomatous interstitial nephritis: Our experience of 14 patients

Renal sarcoidosis

Renal sarcoidosis (RS) is a rare form of sarcoidosis that results in granulomatous inflammation of renal parenchyma. We describe the epidemiology, pathogenesis, clinical features, diagnostic approach, treatment strategies and outcomes of this condition. RS occurs most commonly at the time of initial presentation of sarcoidosis but can at any time along the course of the disease. The most common presenting clinical manifestations of RS are renal insufficiency or signs of general systemic inflammation. End-stage renal disease requiring dialysis is a rare initial presentation of RS. The diagnosis of RS should be considered in patients who present with renal failure and have either a known diagnosis of sarcoidosis or have extra-renal features consistent with sarcoidosis. A renal biopsy helps to establish the diagnosis of RS, with interstitial non-caseating granulomas confined primarily to the renal cortex being the hallmark pathological finding. However, these histologic findings are not specific for sarcoidosis, and alternative causes for granulomatous inflammation of the renal parenchyma should be excluded. Corticosteroids are the drug of choice for RS. Although RS usually responds well to corticosteroids, the disease may have a chronic course and require long-term immunosuppressive therapy. The risk of progression to ESRD is rare.

A non-immunocompromised host with nontuberculous mycobacteria-associated tubulointerstitial nephritis

A 50-year-old man was admitted to our hospital with the complaints of fever and general malaise. He had no history of human immunodeficiency virus (HIV) infection or treatment with immunosuppressive agents. We performed renal biopsy to investigate possible acute kidney injury. Pathological findings showed inflammatory cell infiltration, including granulomatous lesions in the interstitium. We diagnosed the patient with acute granulomatous tubulointerstitial nephritis. We initiated prednisolone (PSL) 40 mg/day (0.6 mg/kg), in combination with isoniazid for a latent tuberculosis infection, because of positive results in interferon-γ release assays. The patient's fever and malaise promptly disappeared, and his renal function improved. After the patient had been discharged, Mycobacterium intracellulare grew in cultures of his renal tissue and urine. We gradually reduced the dose of PSL; we initiated combination therapy with ethambutol, clarithromycin, and rifampin. After 2 years of follow-up, the patient continued treatment for chronic kidney disease; it has since enabled him to avoid renal replacement therapy. This report describes a rare instance of nontuberculous mycobacteria-associated tubulointerstitial nephritis in a patient without a history of HIV infection or organ transplantation. In differential diagnosis of granulomatous tubulointerstitial nephritis, clinicians should consider drugs, sarcoidosis, tubulointerstitial nephritis and uveitis syndrome, vasculitis, and infections (e.g., involving mycobacteria). Prompt microbiological examinations, especially of urine or biopsy cultures, are vital for diagnosis.

Granulomatous nephritis: A rare presentation of juvenile-onset sarcoidosis

Sarcoidosis is rare in children. Incidence and prevalence of sarcoidosis in India are not known. Renal involvement in childhood sarcoidosis is further rare with no clear data about prevalence. Here we report a case of a 13-year-old girl who presented with sarcoidosis with multi-system involvement including renal sarcoidosis. She initially presented with pyrexia of unknown origin and cervical lymphadenopathy - evaluation of which led to diagnosis of sarcoidosis. Later, after development of pulmonary involvement, she was treated with oral prednisolone and azathioprine. She again defaulted on medicines and later presented with renal failure and was diagnosed with a renal sarcoidosis. She was treated with oral prednisolone and mycophenolate mofetil with which she gradually improved with normal renal functions.

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.

Granulomatous Interstitial Nephritis - A Series of Six Cases

Granulomatous interstitial nephritis is an uncommon variant accounting for about 6% of all tubulointerstitial nephritis. The etiology can be drugs such as antibiotics and nonsteroidal anti-inflammatory drugs and infections such as tuberculosis, sarcoidosis, and fungal infections. Renal biopsy remains the gold standard for establishing the diagnosis. Here, we present a series of six cases of granulomatous interstitial nephritis, of which two cases were associated with lupus nephritis and another two cases with crescentic glomerulonephritis. Focal segmental glomerulosclerosis and mesangiosclerosis with chronic tubulointerstitial nephritis were detected in the rest of the cases. Most of the patients presented with features of nephrotic syndrome. Urine analysis showed albuminuria in all cases. In renal biopsy, interstitial epithelioid cell granuloma was a constant feature along with which there were foci of necrosis and moderate fibrosis in few cases. But none of our cases had any relevant history of prolonged drug intake. Tuberculosis and fungal infections were also ruled out. Thereby in this case series, we subgroup all the cases into two category four cases associated with granulomatous nephritis and two cases with idiopathic granulomatous nephritis.

Histopathologic review of granulomatous inflammation

Granulomatous inflammation is a histologic pattern of tissue reaction which appears following cell injury. Granulomatous inflammation is caused by a variety of conditions including infection, autoimmune, toxic, allergic, drug, and neoplastic conditions. The tissue reaction pattern narrows the pathologic and clinical differential diagnosis and subsequent clinical management. Common reaction patterns include necrotizing granulomas, non necrotizing granulomas, suppurative granulomas, diffuse granulomatous inflammation, and foreign body giant cell reaction. Prototypical examples of necrotizing granulomas are seen with mycobacterial infections and non-necrotizing granulomas with sarcoidosis. However, broad differential diagnoses exist within each category. Using a pattern based algorithmic approach, identification of the etiology becomes apparent when taken with clinical context. The pulmonary system is one of the most commonly affected sites to encounter granulomatous inflammation. Infectious causes of granuloma are most prevalent with mycobacteria and dimorphic fungi leading the differential diagnoses. Unlike the lung, skin can be affected by several routes, including direct inoculation, endogenous sources, and hematogenous spread. This broad basis of involvement introduces a variety of infectious agents, which can present as necrotizing or non-necrotizing granulomatous inflammation. Non-infectious etiologies require a thorough clinicopathologic review to narrow the scope of the pathogenesis which include: foreign body reaction, autoimmune, neoplastic, and drug related etiologies. Granulomatous inflammation of the kidney, often referred to as granulomatous interstitial nephritis (GIN) is unlike organ systems such as the skin or lungs. The differential diagnosis of GIN is more frequently due to drugs and sarcoidosis as compared to infections (fungal and mycobacterial). Herein we discuss the pathogenesis and histologic patterns seen in a variety of organ systems and clinical conditions.

Granulomatous interstitial nephritis

Granulomatous interstitial nephritis (GIN) is a rare entity detected in ∼0.5-0.9% of all renal biopsies. GIN has been linked to several antibiotics such as cephalosporins, vancomycin, nitrofurantoin and ciprofloxacin. It is also associated with NSAIDs and granulomatous disorders such as sarcoidosis, tuberculosis, fungal infections, and granulomatosis with polyangiitis. Renal biopsy is critical in establishing this diagnosis, and the extent of tubular atrophy and interstitial fibrosis may aid in determining prognosis. Retrospective data and clinical experience suggest that removal of the offending agent in conjunction with corticosteroid therapy often results in improvement in renal function. We describe a patient with a history of multiple spinal surgeries complicated by wound infection who presented with confusion and rash with subsequent development of acute kidney injury. Urinalysis demonstrated pyuria and eosinophiluria, and renal biopsy revealed acute interstitial nephritis with granulomas. These findings were attributed to doxycycline treatment of his wound infection. This review explores the clinical associations, presentation, diagnosis, and treatment of this uncommon cause of acute kidney injury.

Etiological diagnosis of granulomatous tubulointerstitial nephritis in the tropics

Background

Granulomatous tubulointerstitial nephritis (GIN) is common due to infections, drugs or sarcoidosis. However, the cause is often difficult to establish and the studies are limited. We studied the etiology of GIN and compared the clinical and histological features and outcome in different etiologies at a tertiary care center in North India.

Methods

Renaö biopsies from GIN cases diagnosed from January 2004 to April 2014 were retrieved. Stain for acid fast bacilli was performed in all biopsies. Etiological diagnosis was based on clinical features, extra-renal manifestations, radiology, history of drug intake and demonstration of infective agent. Tissue PCR for tubercular DNA was performed in seven biopsies.

Results

Seventeen GIN patients [mean age 35 ± 15 years; males 11] were identified. Tuberculosis was the commonest etiology followed by idiopathic, sarcoidosis and fungal. Both tuberculosis and sarcoidosis patients presented with subnephrotic proteinuria and raised serum creatinine. Acid fast bacilli were demonstrated in 1/9 and necrosis was demonstrated in 3/9 granulomas in tuberculosis. Tissue PCR for tubercular DNA was positive in six TB patients and negative in one sarcoidosis patient. Patients responded well to appropriate therapy.

Conclusion

Etiological diagnosis of GIN is essential for timely and appropriate therapy. Tuberculosis is the commonest etiology (53%) in the tropics. Necrosis in granuloma, demonstration of acid fast bacilli, blood interferon gamma release assay and urine culture is not sensitive for the diagnosis of tuberculosis in GIN. Our findings suggest that tissue PCR for tuberculosis performed in an appropriate clinical setting is useful in the diagnostic evaluation of GIN.

Granulomatous interstitial nephritis secondary to chronic lymphocytic leukemia/small lymphocytic lymphoma

Granulomatous interstitial nephritis (GIN) is an uncommon pathologic lesion encountered in 0.5% to 5.9% of renal biopsies. Drugs, sarcoidosis, and infections are responsible for most cases of GIN. Malignancy is not an established cause of GIN. Here, we report a series of 5 patients with GIN secondary to chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). Patients were mostly elderly white males with an established history of CLL/SLL who presented with severe renal impairment (median peak serum creatinine, 7.3 mg/dL), leukocyturia, and mild proteinuria. One had nephromegaly. In 2 patients, the development and relapse of renal insufficiency closely paralleled the level of lymphocytosis. Kidney biopsy in all patients showed GIN concomitant with CLL/SLL leukemic interstitial infiltration. Granulomas were nonnecrotizing and epithelioid and were associated with giant cells. One biopsy showed granulomatous arteritis. One patient had a granulomatous reaction in lymph nodes and skin. Steroids with/without CLL/SLL-directed chemotherapy led to partial improvement of kidney function in all patients except 1 who had advanced cortical scarring on biopsy. In conclusion, we report an association between CLL/SLL and GIN. Patients typically present with severe renal failure due to both GIN and leukemic interstitial infiltration, which tends to respond to steroids with/without CLL/SLL-directed chemotherapy. The pathogenesis of GIN in this clinical setting is unknown but may represent a local hypersensitivity reaction to the CLL/SLL tumor cells.

Renal failure due to granulomatous interstitial nephritis in native and allograft renal biopsies: experience from a tertiary care hospital

Granulomatous interstitial nephritis is a rare cause of renal failure in both native and allograft renal biopsies. Drugs and sarcoidosis are the commonest causes of granulomatous interstitial nephritis as reported in Western countries. Unlike the west, tuberculosis is the commonest cause of granulomatous interstitial nephritis in Indian subcontinent. The etiological factors, clinical course, glomerular and tubulointerstitial changes associated with granulomatous interstitial nephritis have been analyzed in the present study along with the outcome in patients with granulomatous interstitial nephritis.