ANCA-Associated Kidney Disease: Secondary Causes
In this issue of the American Journal of Kidney Diseases there is an interesting case report on ANCA-associated glomerulonephritis in systemic-onset juvenile idiopathic arthritis (SoJIA), written by Belot et al. The authors describe 3 cases with high disease activity who presented with anti-neutrophilic cytoplasmic antibody (ANCA)-associated glomerulonephritis 1 to 6 years after developing SoJIA. End-stage kidney disease developed in the other two patients, leading to death in one of them.
ANCA-associated disease is classically idiopathic, but there are several known secondary causes. We have developed a set of anagrams to explore the other causes of ANCA-associated kidney disease. Test your knowledge!
An anagram is a type of word play, a set of jumbled letters that can be rearranged to ﬁnd a hidden answer (original word/phrase). For example, “main party here (1 word)”is an anagram for “hypernatremia.” The anagrams below bring to the reader’s attention some of the important factors to consider while obtaining a history, physical examination, and laboratory data in the evaluation of a patient with a secondary cause ANCA disease. Some clues could be related to primary ANCA vasculitis diseases. Each anagram is followed by a hint meant to intellectually direct the reader towards the correct answer. The number of words that would form the final answer is indicated in parentheses next to the anagram.
1. NOTION IS RITE (1 word)
A 19-year-old man with severe acne conglobata and ulcerated pyoderma gangrenosum on the face was seen by a dermatologist and prescribed this medication. Two weeks later his internist notes 2.5 gm of proteinuria, hematuria, and positive cANCA. A kidney biopsy confirms pauci immune glomerular nephritis.
2. MICE STYLE SCISSORS (2 words)
A 42-year-old woman with a history of Barrett’s esophagus, pulmonary hypertension, and thickening of the skin of her fingers presents with rapidly progressive kidney failure. Kidney pathology shows crescentic glomerulonephritis without mucoid intimal proliferation of the interlobular arteries or fibrinoid necrosis of the afferent arterioles. Immunofluorescence shows linear deposition of IgG along the glomerular capillary wall. Anti-glomerular basement membrane antibody and MPO-ANCA are simultaneously detected by an enzyme linked immunosorbent assay. What systemic rheumatologic disease does she have?
3. A TIC OR GAITER TOURING (2 words)
A 44-year-old man with pansinusitis, otitis, mastoiditis, and chronic lymphocytic meningitis with positive pANCA and anti-MPO antibodies presents with a three-out-of-four diastolic murmur with echocardiogram showing septal hypertrophy leading to aortic valve closure. What is her cardiac disease?
4. HIRE AND LAZY (1 word)
A 52-year-old African American woman with hypertension, hyperlipidemia, and NYHA class 3 congestive heart failure was recently started on isosorbidedinitrate along with this medication. She presents to the emergency room with hemoptysis, chest pain, increasing lower extremity edema, fever, arthralgia, and myalgia. Her serum creatinine is 3.5 mg/dL and eGFR 16 ml/min/1.73m2, and urinalysis showed 2+ blood, 30-50 RBC/hpf, and red blood cell casts. Serologies shows positivity for ANA, anti-dsDNA, and MPO-ANCA. Serum complements are normal. Kidney biopsy reveals focal crescentic necrotizing glomerulonephritis with negative immunofluorescence, consistent with pauci-immune ANCA-positive vasculitis.
5. A RECENT PET (1 word)
A 50-year-old woman with progressive rheumatoid arthritis with erosive joint disease on methotrexate was prescribed this medication by her rheumatologist. She comes in for a follow-up visit 1 month later and reports symptoms of lethargy, upper respiratory tract symptoms, and a skin rash. On further testing she is found to have an elevated serum creatinine of 2.5mg/dL, a eGFR of 22 ml/min/1.73m2, and a positivecANCA. Skin and kidney biopsies are performed, which diagnose small vessel vasculitis and necrotizing pauci immune crescentic glomerulonephritis, respectively.
6. HELP PURSUIT SIN (2 words)
A 74-year-old Japanese woman presents with purpura, reduced GFR, and diffuse joint pains. Laboratory tests reveal anemia and hypocomplemenremia. A chest X-ray shows diffuse pulmonary infiltrates, with bronchial lavage evidence of diffuse alveolar hemorrhage. Immunologic studies shows positive ANA, dsDNA, and MPO-ANCA. A kidney biopsy shows cellular crescents, and moderate increase in mesangial cells and matrix. IF demonstrates diffuse staining for IgM, C3, IgA, and IgG, with focal staining for IgM, C3, and C1q in the mesangium. EM shows subepithelial and mesangial deposits with few subendothelial deposits. ANCA vasculitis can sometimes be associated with this common rheumatologic kidney disease.
Answers can be found here.
To view the article please go to AJKD.
Here’s to a fruitful learning experience!
Questions prepared by:
Mohini Alexander,MD and Divya Monga, MD (Nephrology Fellows- Hofstra NSLIJ School of Medicine)
Edited by Kenar D. Jhaveri, MD (eAJKD Blog Editor)
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