Leukocyturia and hematuria enable non-invasive differentiation of Bowman's capsule rupture severity in PR3-ANCA glomerulonephritis

BACKGROUND

Renal involvement is a common and severe complication of anti-neutrophil cytoplasmic antibody-(ANCA)-associated vasculitis potentially resulting in pauci-immune necrotizing and crescentic ANCA glomerulonephritis (GN) with rapid deterioration of kidney function, progression to end stage kidney disease or, if left untreated, lethal exitus. Analysis of the urinary sediment routinely supports clinical management of ANCA GN, but histopathological implications of aberrancies in the urinary sediment mostly remain elusive. Therefore, we aimed to systematically assess the correlation of aberrancies in the urinary sediment and clinico-pathologic findings.

METHODS

A total of 42 kidney biopsies with ANCA GN were retrospectively analyzed in a single-center observational study. Laboratory and histopathological parameters were systematically analyzed and correlated with findings of the urinary sediment.

RESULTS

In the overall ANCA GN cohort, leukocyturia and hematuria were associated among each other, and with markers for non-selective glomerular damage, respectively. Non-invasive measurement of leukocyturia indicated focal (but not extensive) Bowman's capsule rupture (BCR) specifically in proteinase-3 (PR3)-ANCA GN, whereas hematuria correlated with extensive (but not focal) BCR. Concerning intrarenal immune cell infiltration, leukocyturia was associated with tubulointerstitial plasma cell infiltration in PR3-ANCA GN. Finally, none of these associations were detectable in myeloperoxidase-ANCA GN, implying different modes of kidney damage.

CONCLUSION

We herein expand our current knowledge by providing evidence that leukocyturia and hematuria enable non-invasive differentiation of BCR severity specifically in PR3-ANCA GN.

Biopsy-proven kidney involvement in hypocomplementemic urticarial vasculitis

BACKGROUND

Hypocomplementemic urticarial vasculitis (HUV) is a rare systemic vasculitis. We aimed to describe the kidney involvement of HUV in a multicenter national cohort with an extended follow-up.

METHODS

All patients with HUV (international Schwartz criteria) with a biopsy-proven kidney involvement, identified through a survey of the French Vasculitis Study Group (FVSG), were included. A systematic literature review on kidney involvement of HUV was performed.

RESULTS

Twelve patients were included, among whom 8 had positive anti-C1q antibodies. All presented with proteinuria, from mild to nephrotic, and 8 displayed acute kidney injury (AKI), requiring temporary haemodialysis in 2. Kidney biopsy showed membrano-proliferative glomerulonephritis (MPGN) in 8 patients, pauci-immune crescentic GN or necrotizing vasculitis in 3 patients (with a mild to severe interstitial inflammation), and an isolated interstitial nephritis in 1 patient. C1q deposits were observed in the glomeruli (n = 6), tubules (n = 4) or renal arterioles (n = 3) of 8 patients. All patients received corticosteroids, and 9 were also treated with immunosuppressants or apheresis. After a mean follow-up of 8.9 years, 6 patients had a preserved renal function, but 2 patients had developed stage 3-4 chronic kidney disease (CKD) and 4 patients had reached end-stage kidney disease (ESKD), among whom 1 had received a kidney transplant.

CONCLUSION

Renal involvement of HUV can be responsible for severe AKI, CKD and ESRD. It is not always associated with circulating anti-C1q antibodies. Kidney biopsy shows mostly MPGN or crescentic GN, with frequent C1q deposits in the glomeruli, tubules or arterioles.

Clinical associations of renal involvement in ANCA-associated vasculitis

OBJECTIVE

Renal involvement in anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis is associated with significant morbidity and higher mortality rates. This study examined clinical manifestations associated with renal involvement in ANCA-associated vasculitis within a large, international cross-sectional cohort.

METHODS

Univariate and multivariate analyses were performed to identify clinical factors associated with renal disease, which was defined as i) a serum-creatinine >30% above normal and a fall in creatinine-clearance >25%; or ii) haematuria attributable to active vasculitis.

RESULTS

The study cohort include 1230 patients from 31 countries; 723 (58.8%) presented with renal involvement: microscopic polyangiitis (82.2%), granulomatosis with polyangiitis (58.6%), and eosinophilic granulomatosis with polyangiitis (26.4%). The following clinical and laboratory factors were more common among patients with renal disease: age (OR 1.01, 95% CI 1.01-1.02), fever (OR 1.97, 95% CI 1.35-2.88), fatigue (OR 1.55, 95% CI 1.14-2.10), weight loss (OR 1.62, 95% CI 1.23-2.12), polyarthritis (OR 1.39, 95% CI 1.02-1.89), petechiae/purpura (OR 1.47, 95% CI 1.06-2.05), pulmonary haemorrhage (OR 5.23, 95% CI 1.39-19.63), gastrointestinal symptoms (OR 2.19, 95% CI 1.34-3.58), seizures (OR 3.42, 95% CI 1.26-9.30), lower serum albumin (OR 2.42, 95% CI 1.64-3.57), higher CRP (OR 2.06, 95% CI 1.04-4.06), low serum C3 at baseline (OR 3.86, 95% CI 1.30-11.53), myeloperoxidase- (OR 7.97, 95% CI 2.74-23.20) and proteinase 3-ANCA (OR 3.40, 95% CI 1.22-9.50). The following clinical factors were less common among patients with renal disease: mononeuritis multiplex (OR 0.63, 95% CI 0.41-0.98), proptosis/exophthalmos (OR 0.19, 95% CI 0.06-0.59), nasal polyps (OR 0.32, 95% CI 0.19-0.55), septal defect/perforation (OR 0.29, 95% CI 0.14-0.60), respiratory distress/pulmonary fibrosis/asthma (OR 0.08, 95% CI 0.04-0.19), and wheeze/obstructive airway disease (OR 0.29, 95% CI 0.16-0.52).

CONCLUSION

In this large international study, several clinical and laboratory factors were identified as associated with renal involvement in ANCA-associated vasculitis.

Unusual case of chronic recurrent multifocal osteomyelitis

BACKGROUND

Chronic recurrent multifocal osteomyelitis (CRMO) is a rare auto-inflammatory bone disorder that primarily affects young girls, with a mean age of 10 years at onset. Generally, it is a self-limited disease. However, recent data indicate that more than 50% of patients have a chronic persistent disease and about 20% a recurring course of this condition. Also, there are more cases reported with associated auto-inflammatory and autoimmune diseases. In this case report, we present a rare case of sporadic CRMO in which the patient eventually developed C-ANCA (cytoplasmic anti-neutrophil cytoplasmic antibodies)-associated renal vasculitis and hyperparathyroidism.

CASE PRESENTATION

A 14 year old female patient was brought to the emergency department with a sudden onset of left leg pain and oedema. After physical evaluation and initial investigation, she was diagnosed with femoral and pelvic deep vein thrombosis. While searching for possible thrombosis causes, osteomyelitis of the left leg was identified. Additional CT and MRI scans hinted at the CRMO diagnosis. Due to the multifocal lesions of CRMO, endocrinological evaluation of calcium metabolism was done. The results showed signs of hyperparathyroidism with severe hypocalcaemia. Moreover, when kidney damage occurred and progressed, a kidney biopsy was performed, revealing a C-ANCA associated renal vasculitis. Treatment was started with cyclophosphamide and prednisolone according to the renal vasculitis management protocol. Severe metabolic disturbances and hyperparathyroidism were treated with alfacalcidol, calcium and magnesium supplements. Secondary glomerulonephritis (GN) associated hypertension was treated with ACE (angiotenzine converting enzyme) inhibitors. Anticoagulants were prescribed for deep vein thrombosis. After 1.5 years of treatment, the patient is free of complaints. All microelement and parathormone levels are within normal range. Kidney function is now normal. To date, there are no clinical or diagnostic signs of deep vein thrombosis.

CONCLUSIONS

This case report presents a complex immunodysregulatory disorder with both auto-inflammatory and autoimmune processes. We hypothesize that the long lasting active inflammation of CRMO may induce an autoimmune response and result in concomitant diseases like C-ANCA-associated vasculitis in our patient. Any potential specific pathogenic relationships between these two rare pathologies may need to be further studied. Furthermore, there is a lack of specific biomarkers for CRMO and more studies are necessary to identify CRMO's characteristic patterns and how to best monitor disease progression.

Hydralazine-associated vasculitis: Overlapping features of drug-induced lupus and vasculitis

INTRODUCTION

Hydralazine is an antihypertensive medication that has been associated with drug-induced lupus erythematosus (DIL) as well as ANCA-associated vasculitis (AAV). Although rare, early diagnosis is critical since drug cessation is the mainstay of therapy. This retrospective study aims to characterize the clinical, laboratory, and histopathologic features of this disease.

METHODS

Once approval was obtained from the Institutional Review Board at the University of Iowa, all patients carrying a diagnosis of vasculitis (ICD9 code: 447.6 or ICD10 code: I77.6, I80, L95, M30, or M31) and positive ANCA lab results over the past 15 years were identified. Age, gender, comorbid conditions, medications taken over the prior 6 months, laboratory data, including electrolytes, urine studies and serologies, chest x-rays, CT scans, and pathologic biopsy records were abstracted from the electronic medical record.

RESULTS

323 cases of AAV were identified, of which 12 were exposed to hydralazine, all at the time of diagnosis. The average duration of hydralazine therapy was 22 months and mean cumulative dose was 146g. Patients were typically older (70.3 years old) with slight female preponderance (7 females). Eleven patients presented with dyspnea, fatigue, and unintentional weight loss. Five had polyarthralgias and 8 had lower extremity petechiae. All 12 patients were both ANA and ANCA positive. ANA titers ranged from 1:160 and 1:2560. Ten were of diffuse pattern while 2 were nucleolar. ANCA titers ranged from 1:320 to 1:2560. Eleven had a pANCA pattern while one had cANCA. All 12 patients were positive for histone and 11 were positive for myeloperoxidase antibodies. Eleven also had dsDNA antibodies, and 4 had anti-cardiolipin IgG or IgM antibodies. Nine patients were also hypocomplementemic (mean C3 level: 88.4mg/dL; mean C4 level: 16.5mg/dL). All patients had variable levels of proteinuria (1+ to 3+) and eleven had active urine sediment. Urine protein:creatinine ratios ranged from 0.2 to 1.7. Of the 6 patients who underwent kidney biopsy, all 6 showed pauci-immune crescentic glomerulonephritis. Seven patients had bilateral pulmonary interstitial infiltrates and four had pleural effusions on CT scan. Four had pericardial effusions as demonstrated by echocardiography.

CONCLUSIONS

Hydralazine-associated vasculitis is a drug-associated autoimmune syndrome that presents with interstitial lung disease, hypocomplementemia, and pauci-immune glomerulonephritis. Patients have elements of both DIL and DIV, as manifested by high ANA and ANCA titers as well as the presence of histone and MPO antibodies. Further research is needed to understand the etiopathogenesis of this condition.

Anti-neutrophil cytoplasmic antibody-associated vasculitis with renal involvement: Analysis of 89 cases

INTRODUCTION

The anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis with renal involvement are associated with high morbi-mortality. In this study we analyse if the prognosis of these diseases have improved in recent years, and which factors influence the outcomes.

MATERIAL AND METHODS

Retrospective single-centre observational study, which included all patients diagnosed with microscopic polyangiitis and granulomatosis with polyangiitis with renal involvement in the last 25 years. Demographic, clinical and biochemical parameters of prognostic interest were recorded. The differences between four chronological periods were analysed, along with the determinants of a poor outcome (death or end-stage renal disease).

RESULTS

Eighty-nine patients were included (mean age 64±15 years). Sixty-four patients (72%) had microscopic polyangiitis and 25 (28%) granulomatosis with polyangiitis. During the study period, 37 (42%) patients died. Through Cox regression analysis, the best determinants of mortality were the initial glomerular filtration rate (HR 0.911; P=.003), Charlson comorbidity index (HR 1.513; P<.0001) and tobacco smoking (HR 1.816; P=.003). 35% developed end-stage renal disease, and the best determinants (by competing-risk regression) were: initial glomerular filtration rate (sub-hazard ratio [SHR]: 0.791; P<.0001), proteinuria (SHR: 1.313; P<.0001), and smoking status (SHR: 1.848; P=.023). No differences were found in patients' mortality or renal survival between the different study periods.

CONCLUSIONS

Prognosis of anti-neutrophil cytoplasm antibodies vasculitis with renal involvement treated with conventional immunosuppressive therapy remains unsatisfactory, and continues to have increased long-term complications and mortality.