MPO-ANCA-positive crescentic necrotizing glomerulonephritis and tubulointerstitial nephritis with renal eosinophilic infiltration and peripheral blood eosinophilia

Renal Involvement in IgG4-Related Disease: From Sunlight to Twilight

IgG4-Related Disease (IgG4-RD) is a fibroinflammatory condition characterized by a typical histopathological pattern (dense lymphoplasmacytic infiltrate with prevalent IgG4+ plasma cells and storiform fibrosis), which may involve the kidney both directly (IgG4-related kidney disease, IgG4-RKD) or indirectly, as a consequence of post-renal ureteral obstruction due to retroperitoneal fibrosis (IgG4-RD RF). The most frequent presentation of IgG4-RKD is IgG4-related tubulointerstitial nephritis (TIN), but a glomerular disease can be present, in most of the cases a membranous nephropathy. Albeit steroid-responsive, in some cases renal manifestations may lead to progressive and permanent organ damage. In this review we describe four clinical cases representative of typical and less typical renal manifestations of IgG4-RD, emphasizing a potential, subclinical, early involvement of the kidney in the disease.

Clinical and morphologic spectrum of renal involvement in idiopathic hypereosinophilic syndrome

BACKGROUND

To explore the clinical and pathological features of renal lesions in patients with kidney involvement in idiopathic hypereosinophilic syndrome (IHES).

METHODS

The demographic, clinical, and pathological characteristics and the treatment and follow-up data were analyzed.

RESULTS

We identified 18 patients with IHES and renal involvement. Eleven patients presented with nephrotic syndrome, and 6 patients had impaired renal function. 15 patients underwent renal biopsy, and the pathological findings included the following: membranoproliferative glomerulonephritis in 3 patients; minimal-change disease in 3; mesangial proliferative nephritis in two; IgA nephropathy in 2; membranous nephropathy in two; chronic interstitial nephritis in two; focal segmental sclerosis in one; and eosinophil infiltration into the renal interstitium in 11 and into the glomerulus in 3. After treatment with glucocorticoids, the eosinophil count decreased. 15 patients were followed up, and 14 showed a decrease in urinary protein or renal function recovery. When glucocorticoids were discontinued, eosinophil increased (8 cases), urine protein increased (1 case), and 1 patient progressed to end-stage renal disease.

CONCLUSIONS

Nephrotic syndrome with or without renal insufficiency is the main clinical manifestation. A wide spectrum of renal lesions can be observed in patients with IHES. Eosinophil infiltration into the renal interstitium was common in these patients. Most patients have a good prognosis after glucocorticoid therapy.

Infective endocarditis mimicking ANCA-associated vasculitis: does it require immunosuppressive therapy?: A case report and literature review

RATIONALE

In the course of endocarditis, the development of antineutrophil cytoplasmic antibody (ANCA)-mediated disease introduces the dilemma of determining the best treatment approach for immune conditions, whether immunosuppressant therapy should be added to antibiotic treatment has remained controversial.

PATIENT CONCERNS

A 33-year-old man presented with progressive fever lasting for 7 months, and swelling, pain, and purpura in the arms and legs. The patient showed multiple autoantibodies including cytoplasmic ANCA, antiproteinase 3, rheumatoid factor, and anti-beta 2 glycoprotein I. Blood culture was positive for viridans streptococcus, and renal biopsy revealed glomerulonephritis and interstitial nephritis.

DIAGNOSIS

Endocarditis caused by viridans streptococci, ANCA-associated vasculitis, and congenital ventricular septal defect.

INTERVENTIONS

In addition to effective antibiotics, he also received twice intravenous corticosteroids and intravenous immunoglobulin therapy, and a low dose of cyclophosphamide. At last, the patient received congenital ventricular septal defect repair and debridement.

OUTCOMES

The abnormal clinical manifestations, including renal failure and loss of strength, recovered rapidly with corticosteroid therapy in addition to antibiotic treatment. After 6 months without any medications, he remained asymptomatic and was able to live normally.

LESSONS

In this case with endocarditis and ANCA-associated vasculitis, we highlighted the importance of biopsy and immunosuppressive therapy. Histopathologic examination is required for diagnosis and treatment in such case. Identifying patients who have endocarditis and ANCA positivity with vasculitis pathologic features will require corticosteroid/immunosuppressives in addition to the antibiotics therapy.

Acute tubulointerstitial nephritis with germinal centers in antineutrophil cytoplasmic antibody-associated vasculitis: A case report and literature review

RATIONALE

Occasionally, tubulointerstitial lesions can be found in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). However, significantly isolated tubulointerstitial nephritis (TIN) with germinal centers is rare.

PATIENT CONCERNS

A 17-year-old Chinese Han patient showed rapidly progressive glomerulonephritis, anuria, and serum creatinine of 19.4 mg/dL.

DIAGNOSIS

He had positive ANCA targeting myeloperoxidase (55.0 RU/mL). The renal biopsy showed crescent formation in 100% of glomeruli. Of special note, the glomerular crescents were surrounded by granulomatous inflammation, extensive tubular destruction or disappearance, and massive interstitial infiltration. A diagnosis of AAV was thus made with the involved organ restricted to the kidney.

INTERVENTIONS

The patient underwent 7 rounds of plasmapheresis, 3 pulses of methylprednisolone therapy (500 mg per pulse), and oral prednisolone (50 mg/d). Rituximab (500 mg) was used after the plasma exchange treatment.

OUTCOMES

ANCA was negative, while anti-modified C-reactive protein (anti-mCRP) antibodies remained positive. The patient was dependent on hemodialysis. We found anti-mCRP antibody in the serum of the patient, with the major epitope on amino acids 35 to 47 of mCRP.

LESSONS

We proposed that the anti-mCRP antibody might play an important role in this case of acute TIN in AAV.

An Atypical Case of Non-asthmatic Eosinophilic Granulomatosis with Polyangiitis Finally Diagnosed by Tissue Biopsy

A 78-year-old woman with fever of unknown origin that had persisted for 3 months, systemic edema, and cervical lymphadenopathy was admitted to our hospital. Skin purpura and jaw claudication were subsequently observed. Histopathological examinations of the lymph nodes, skin, and temporal artery revealed findings characteristic of eosinophilic granulomatosis with polyangiitis (EGPA). However, she had no past medical history of asthma with modest eosinophilia. Although EGPA is a systemic vasculitis characterized by asthma and eosinophilia, various limited forms have been described. This was therefore considered to be an atypical form of non-asthmatic EGPA complicating with temporal arteritis (TA) diagnosed by tissue biopsy.

Renal thrombotic microangiopathy and FIP1L1/PDGFRα-associated myeloproliferative variant of hypereosinophilic syndrome

We report a case of renal thrombotic microangiopathy (TMA) in a myeloproliferative variant of hypereosinophilic syndrome (HES) in a 24-year-old man which resolved with imatinib therapy. This is one of a few cases in the literature to date describing TMA in HES, suggesting that the pathogenesis of thrombosis is at least in part related to damage from activated eosinophils.

Renal involvement in idiopathic hypereosinophic syndrome

The hypereosinophilic syndromes (HESs) are a group of disorders marked by the sustained overproduction of eosinophils, in which eosinophilic infiltration and mediator release cause damage to multiple organs. In idiopathic HES, the underlying cause of hypereosinophilia (HE) remains unknown despite thorough aetiological work-up. Kidney disease is thought to be rare in HES. Renal manifestations described include eosinophilic interstitial nephritis, various types of glomerulopathies, thrombotic microangiopathy (TMA) and electrolyte disturbances. The diagnosis must be made in time, because a recovery of renal function can be obtained if treatment is initiated promptly.

A case of ANCA-associated vasculitis with glomerular eosinophilic infiltration: a possible pathogenic implication

We present a 58-year-old male patient with myeloperoxidase antineutrophil cytoplasmic antibody-associated vasculitis with rapidly progressive glomerulonephritis. He failed to fulfill the common American College of Rheumatology criteria for eosinophilic granulomatosis with polyangiitis and was tentatively diagnosed with microscopic polyangiitis. Kidney biopsy showed pauci-immune crescentic necrotizing glomerulonephritis with neutrophilic and eosinophilic infiltration. Previous reports implicate eosinophils in the pathogenesis of this disease. Therefore, this case suggests that infiltrated eosinophils as well as neutrophils might play roles in the development of tissue injury in systemic vasculitis.

Symptomatic anti-neutrophil cytoplasmic antibody-positive disease complicating subacute bacterial endocarditis: to treat or not to treat?

A 54-year-old man was diagnosed with Streptococcus mutans endocarditis of the mitral valve. Serological tests disclosed the presence of multiple autoantibodies including c-ANCA, anti-PR3 and anti-MPO. While the fever subsided with antibiotics, mental status and renal function deteriorated rapidly. Kidney biopsy revealed pauci-immune glomerulonephritis and acute eosinophilic interstitial nephritis. The abnormal clinical features improved rapidly after addition of corticosteroids and cyclophosphamide to the antibiotics. Immunosuppressive agents may be required in a fraction of the patients with infective endocarditis who develop ANCA and ANCA-mediated renal disease. Histological identification of the type of renal disease is imperative for the choice of the treatment.

Renal involvement as the first manifestation of hypereosinophilic syndrome: a case report

Idiopathic hypereosinophilic syndrome is characterized by elevated and prolonged blood eosinophilia along with organ system involvement and malfunction. The heart is the most frequently involved organ, and renal participation is extremely rare. Herein, we report on a case of idiopathic hypereosinophilic syndrome with renal involvement as the first manifestation.

Renal involvement in Churg-Strauss syndrome

BACKGROUND

Churg-Strauss syndrome (CSS) is a rare disorder characterized by asthma, eosinophilia, and systemic vasculitis. Renal involvement is not regarded as a prominent feature, and its prevalence and severity vary widely in published reports that usually refer to small series of selected patients.

METHODS

We examined the prevalence, clinicopathologic features, and prognosis of renal disease in 116 patients with CSS.

RESULTS

There were 48 men and 68 women with a mean age of 51.9 years (range, 18 to 86 years). Signs of renal abnormalities were present in 31 patients (26.7%). Rapidly progressive renal insufficiency was documented in 16 patients (13.8%); urinary abnormalities, 14 patients (12.1%); and chronic renal impairment, 1 patient. There were 3 additional cases of obstructive uropathy. Sixteen patients underwent renal biopsy, which showed necrotizing crescentic glomerulonephritis in 11 patients. Other diagnoses were eosinophilic interstitial nephritis, mesangial glomerulonephritis, and focal sclerosis. Antineutrophil cytoplasmic antibody (ANCA) was positive in 21 of 28 patients (75.0%) with nephropathy versus 19 of 74 patients without (25.7%; P < 0.001). In particular, all patients with necrotizing crescentic glomerulonephritis were ANCA positive. After a median follow-up of 4.5 years, 10 patients died (5 patients with nephropathy) and 7 patients developed mild chronic renal insufficiency. Five-year mortality rates were 11.7% (95% confidence interval, 3.9 to 33.3) in patients with nephropathy and 2.7% (95% confidence interval, 0.7 to 10.7) in those without (P = 0.10).

CONCLUSION

Renal abnormalities are present in about one quarter of patients with CSS. The prevailing picture is ANCA-associated necrotizing crescentic glomerulonephritis; however, other forms of nephropathy also may occur. Outcome and long-term follow-up usually are good.

Prevalence and clinical significance of antineutrophil cytoplasmic antibodies in Churg-Strauss syndrome

OBJECTIVE

Churg-Strauss syndrome (CSS) is classified among the so-called antineutrophil cytoplasmic antibody-associated systemic vasculitides (AASVs) because of its clinicopathologic features that overlap with the other AASVs. However, while antineutrophil cytoplasmic antibodies (ANCAs) are consistently found in 75-95% of patients with Wegener's granulomatosis or microscopic polyangiitis, their prevalence in CSS varies widely and their clinical significance remains uncertain. We undertook this study to examine the prevalence and antigen specificity of ANCAs in a large cohort of patients with CSS. Moreover, we evaluated the relationship between ANCA positivity and clinicopathologic features.

METHODS

Immunofluorescence and enzyme-linked immunosorbent assay were used to determine the presence or absence of ANCAs in 93 consecutive patients at the time of diagnosis. The main clinical and pathologic data, obtained by retrospective analysis, were correlated with ANCA status.

RESULTS

ANCAs were present by immunofluorescence in 35 of 93 patients (37.6%). A perinuclear ANCA (pANCA) pattern was found in 26 of 35 patients (74.3%), with specificity for myeloperoxidase (MPO) in 24 patients, while a cytoplasmic ANCA pattern, with specificity for proteinase 3, was found in 3 of 35 patients (8.6%). Atypical patterns were found in 6 of 30 patients with anti-MPO antibodies (20.0%). ANCA positivity was associated with higher prevalences of renal disease (51.4% versus 12.1%; P < 0.001) and pulmonary hemorrhage (20.0% versus 0.0%; P = 0.001) and, to a lesser extent, with other organ system manifestations (purpura and mononeuritis multiplex), but with lower frequencies of lung disease (34.3% versus 60.3%; P = 0.019) and heart disease (5.7% versus 22.4%; P = 0.042).

CONCLUSION

ANCAs are present in approximately 40% of patients with CSS. A pANCA pattern with specificity for MPO is found in most ANCA-positive patients. ANCA positivity is mainly associated with glomerular and alveolar capillaritis.

Anti-glomerular basement membrane antibody-induced glomerulonephritis with periglomerular granulomatous reaction and massive renal eosinophilic infiltration

We present a case of a 68-year-old man with anti-glomerular basement membrane (anti-GBM) antibody-induced glomerulonephritis accompanied by periglomerular granulomatous reaction and massive eosinophilic infiltration. Periglomerular granulomatous giant cells were derived from macrophages, shown by positive staining for monoclonal antibody against cluster of differentiation 68. Staining for eosinophil cationic protein indicated that activated eosinophils were involved in the tubulitis, as well as in the glomerular injury. The patient was admitted to the hospital with fever, loss of appetite, edema of the extremities, abnormal urinalysis results, and rapid progressive renal failure. At an examination 8 months before admission, his serum creatinine level (1.0 mg/dL [88.4 micromol/L]) and urinalysis results were normal. On admission, an elevated serum creatinine level (5.1 mg/dL [450.8 micromol/L]) and marked eosinophilia (eosinophils, 5.00 x 10(3)/microL [5.00 x 10(9)/L]; 37.2% of total white blood cell count) were observed. Serum anti-GBM antibody titer was high (43 EU), measured by means of an enzyme-linked immunosorbent assay. No respiratory or ophthalmological abnormalities were seen. Intravenous steroid pulse therapy followed by oral prednisolone (PSL) was effective for reducing the fever, eosinophilia, anti-GBM antibody titer, and C-reactive protein level, but did not improve renal function because renal tissue already was irreversibly damaged. Oral PSL dose was tapered off without relapse. The patient underwent long-term hemodialysis therapy, which dissipated the edema. He was discharged from our hospital 65 days after admission. Three months later, his anti-GBM antibody level was less than 10 EU, and the number of peripheral eosinophils stayed with the normal range.

Atypical presentation of Churg-Strauss syndrome: another "forme fruste" of the disease?

Vasculitis is a clinicopathologic process characterized by inflammation and damage to blood vessels. A broad and heterogenous group of syndromes may result from this process, because any type, size, and location of blood vessel may be involved. The cause of these conditions remains unclear, but an autoimmune inflammatory process, characterized by involvement of both neutrophils and endothelial cells, seems to play an important role. In 1951, Churg and Strauss described a clinical syndrome of severe asthma, hypereosinophilia with eosinophilic infiltrates, eosinophilic vasculitis, and granulomata in various organs. Asthma may precede this vasculitis by many years. We report a case of anti-neutrophil cytoplasmic antibody-positive, pauci-immune, crescentic, necrotizing glomerulonephritis with peripheral and interstitial eosinophilia but without asthma. This is very unusual in Churg-Strauss syndrome.