Animal models for anti-neutrophil cytoplasmic antibody-associated vasculitis:Are current models good enough?

Antineutrophil cytoplasmic autoantibody(ANCA)-associated vasculitis(AAV)is a rare and severe systemic autoimmune disease characterized by pauci-immune necrotizing inflammation of small blood vessels.AAV involves multiple organ systems throughout the body.Our knowledge of the pathogenesis of AAV has increased considerably in recent years,involving cellular,molecular and genetic factors.Because of the controlled environment with no other confounding factors,animal models are beneficial for studying the mechanistic details of disease development and for providing novel therapeutic targets with fewer toxic side effects.However,the complexity and heterogeneity of AAV make it very difficult to establish a single animal model that can fully represent the entire clinical spectrum found in patients.The aim of this review is to overview the current status of animal models for AAV,outline the pros and cons of methods,and propose potential directions for future research.

Myeloperoxidase-antineutrophil cytoplasmic antibody-associated vasculitis with headache and kidney involvement at presentation and with arthralgia at relapse:A case report

BACKGROUND Patients with proteinase 3-antineutrophil cytoplasmic antibody associated vasculitis(AAV)experience different manifestations at the initial onset and relapse.However,such cases of different initial and relapse manifestations have not been reported in myeloperoxidase(MPO)-AAV patients.CASE SUMMARY A 52-year-old woman was admitted to our hospital because of headache.Laboratory findings indicated nephrotic range proteinuria and microscopic hematuria,serum creatinine of 243μmol/L,anti-MPO antibody titer of>400 RU/mL,and positive perinuclearantineutrophil cytoplasmic antibody.Renal biopsy showed pauci-immune crescentic glomerulonephritis.The cerebrospinal fluid examination and brain magnetic resonance imaging did not show any abnormality.Therefore,MPO-AAV was diagnosed.Corticosteroids,plasmapheresis,and cyclophosphamide as induction therapy and mycophenolate mofetil(MMF)as maintenance therapy were administered.The patient’s headache disappeared;serum creatinine returned to normal;complete remission of microscopic hematuria and proteinuria was observed.Anti-MPO antibody titer reached normal limits after immunosuppressive treatment.Twenty-five months after stopping the immunosuppressive treatment,the patient relapsed with arthralgia,without neurological or renal involvement.The patient’s arthralgia improved after treatment with prednisone and MMF.CONCLUSION We have reported a rare case of MPO-AAV who initially presented with headache and kidney involvement.However,relapse presented with only arthralgia,which was completely different from the initial manifestations.This case suggests that AAV relapse should be highly suspected in MPO-AAV patients after remission,when clinical manifestations at relapse are different from those at onset.Prednisone and MMF may provide a good choice for refractory arthralgia during relapse in MPO-AAV patients.

Significance of antineutrophil cytoplasmic antibody in adult patients with Henoch-Schnlein purpura presenting mainly with gastrointestinal symptoms

AIM： To test the clinical significance of antineutrophil cytoplasmic antibody （ANCA） in evaluation of adult Henoch-Schonlein purpura （HSP） patients presenting mainly with abdominal symptoms. METHODS： Twenty-eight consecutive HSP patients who presented predominantly with abdominal symptoms were enrolled in this study. Control subjects included 27 ageand sex-matched patients with peptic ulcer disease, colon cancer, acute gastroenteritis, irritable bowel syndrome and colonic polyps. ANCA was measured by indirect immunofluorescence （IIF） in all patients, and follow-up ELISA was performed in patients with positive IIF tests. RESULTS： ANCA was detected in 9 HSP patients by IIF （2 were positive for c-ANCA and 7 were positive for p-ANCA）. No ANCA was found in the control group. The sensitivity and specificity of a positive ANCA test （either c- or p-ANCA） were 32.1% and 100% respectively. Only one out of the 9 patients with positive ANCA by IIF had positive ANCA by ELISA and the antigen was myeloperoxidase （MPO）. The patients positive for ANCA had higher HSP clinical scores, and were more likely to have renal function impairment. Patients with late purpura development were also associated with more severe clinical manifestations. CONCLUSION： A positive ANCA test is associated with more severe symptoms in HSP. After inflammatory bowel disease is excluded, a positive ANCA test provides a clue to the diagnosis of HSP presenting predominantly with abdominal symptoms.

A subset of ulcerative colitis with positive proteinase-3 antineutrophil cytoplasmic antibody

A small subset of patients with active ulcerative colitis is non-responsive to major known non-biological therapies. We reported 5 patients with positive serum proteinase-3 antineutrophil cytoplasmic antibody (PR3-ANCA) and tried to (1) identify the common clinical features of these patients; (2) investigate the efficacy of a novel therapy using a Chinese medicine compound; and (3) attract more gastroenterologists to be engaged in further study of this subset of patients. The common manifestations of disease in these 5 patients included recurrent bloody diarrhea and inflammatory lesions involving the entire colorectal mucosa. Initial treatment with intravenous methylprednisolone successfully induced remission. Four of these 5 patients were steroid-dependence, and immunosuppressants, such as azathioprine and cyclophosphamide, were in effective. In 3 patients, only the particular Chinese medicine compound could induce and maintain remission. One patient underwent colectomy. No vascular inflammatory lesions were found by histopathological examination. Although more cases are needed for confirmation, our study indicates thatulcerative colitis with positive PR3-ANCA may belong to a subtype of refractory ulcerative colitis. The particular Chinese medicine compound used in our study is by far the most effective in the management of these patients, with additional advantages of having no noticeable side-effects and less financial burden.

Risk factors for renal outcomes in children with antineutrophil cytoplasmic antibody-associated vasculitis:a nationwide retrospective study in China

Background Pediatric antineutrophil cytoplasmic antibody-associated vasculitis(AAV)is a life-threatening systemic vasculitis featured by liability to renal involvement.However,there are few studies on the risk factors and predictive models for renal outcomes of AAV in children.Methods Data from 179 AAV children in multiple centers between January 2012 and March 2020 were collected retrospectively.The risk factors and predictive model of end-stage renal disease(ESRD)in AAV were explored.Results Renal involvement was the most typical manifestation(95.5%),and the crescent was the predominant pathological lesion(84.9%).The estimated glomerular filtration rate(eGFR)was evaluated in 114 patients,of whom 59.6%developed ESRD,and the median time to ESRD was 3.20 months.The eGFR[P=0.006,odds ratio(OR)=0.955,95%confidence interval(CI)=0.924–0.987]and the percentages of global glomerulosclerosis(pGGS;P=0.018,OR=1.060,95%CI=1.010–1.112)were independent risk factors for ESRD of renal biopsy.Based on the pGGS and eGFR at renal biopsy,we developed three risk grades of ESRD and one predictive model.The Kaplan‒Meier curve indicated that renal outcomes were significantly different in different risk grades(P<0.001).Compared with serum creatinine at baseline,the predictive model had higher accuracy(0.86 versus 0.58,P<0.001)and a lower coefficient of variation(0.07 versus 0.92)in external validation.Conclusions Renal involvement is the most common manifestation of pediatric AAV in China,of which more than half deteriorates into ESRD.The predictive model based on eGFR at renal biopsy and the pGGS may be stable and accurate in speculating the risk of ESRD in AAV children.

Antineutrophil cytoplasmic antibodies crescentic allograft glomerulonephritis after sofosbuvir therapy

Antineutrophil cytoplasmic antibodies(ANCA) are well known to be associated with several types of vasculitis, including pauci-immune crescentic glomerulonephritis, a form of rapid progressive glomerular nephritis(RPGN). ANCA vasculitis has also been reported after administration of propylthiouracil, hydralazine, cocaine(adulterated with levimasole), allopurinol, penicillamine and few other drugs. All previously reported cases of drug-associated ANCA glomerulonephritis were in native kidneys. Sofosbuvir is a new and effective drug for hepatitis C virus infection. Here, we report a case of ANCA vasculitis and RPGN following sofosbuvir administration in a kidney transplant recipient. It also represents the first case of drug-associated ANCA vasculitis in a transplanted kidney. Further drug monitoring is necessary to elucidate the degree of association and possible causal effect of sofosbuvir and perinuclear ANCA vasculitis.

Successful treatment of granulomatosis with polyangiitis using tocilizumab combined with glucocorticoids:A case report

BACKGROUND Tocilizumab is a humanized monoclonal antibody against the interleukin-6(IL-6)receptor that is commonly used to treat large vessel vasculitis and antineutrophil cytoplasmic antibody-related small vessel vasculitis.However,tocilizumab in combination with glucocorticoids for successfully treating granulomatosis with polyangiitis(GPA)has rarely been reported.CASE SUMMARY Here,we report a 40-year-old male patient who suffered GPA for 4 years.He was treated with multiple rounds of drugs,including cyclophosphamide,Tripterygium wilfordii,mycophenolate mofetil,and belimumab,with no improvement.In addition,he exhibited persistently high IL-6 levels.After tocilizumab treatment,his symptoms improved,and his inflammatory marker levels returned to normal.CONCLUSION Tocilizumab may be effective for treating GPA.

Utility of serological markers in inflammatory bowel diseases: Gadget or magic?

The panel of serologic markers for inflammatory bowel diseases （IBD） is rapidly expanding. Although antiSaccharornyces cerev/siae antibodies （ASCA） and atypical perinuclear antineutrophil cytoplasmic antibodies （P-ANCA） remain the most widely investigated, an increasing amount of experimental data is available on newly discovered antibodies directed against various microbial antigens. The role of the assessment of various antibodies in the current IBD diagnostic algorithm is often questionable due to their limited sensitivity. In contrast, the association of serologic markers with disease behavior and phenotype is becoming increasingly well-established. An increasing number of observations confirms that patients with Crohn＇s disease expressing multiple serologic markers at high titers are more likely to have complicated small bowel disease （e.g. stricture and/or perforation） and are at higher risk for surgery than those without, or with low titers of antibodies. Creating homogenous disease sub-groups based on serologic response may help develop more standardized therapeutic approaches and may help in a better understanding of the pathomechanism of IBD. Further prospective clinical studies are needed to establish the clinical role of serologic tests in IBD.

Seroreactivity against Saccharomyces cerevisiae in patients with Crohn's disease and celiac disease

AIM:To explore whether there was anti-Saccharomyces cerevisiae antibodies (ASCA) positivity in our patients with biopsy-confirmed celiac disease. METHODS:A cohort of patients with inflammatory bowel diseases (42 patients with Crohn's disease and 10 patients with ulcerative colitis) and gluten sensitive enteropathy (16 patients) from Debrecen,Hungary were enrolled in the study. The diagnosis was made using the formally accepted criteria. Perinuclear antineutrophil cytoplasmic antibodies (pANCA) and anti-Saccharomyces cerevisiae antibodies (ASCA), antiendomysium antibodies (EMA),antigliadin antibodies (AGA) and anti human tissue transglutaminase antibodies (tTGA) were investigated. RESULTS:The results showed that ASCA positivity occurred not only in Crohn's disease but also in Celiac disease and in these cases both the IgG and IgA type antibodies were proved. CONCLUSION:It is conceivable that ASCA positivity correlates with the (auto-) immune inflammation of small intestines and it is a specific marker of Crohn's disease.

Cyclophosphamide-associated enteritis presenting with severe protein-losing enteropathy in granulomatosis with polyangiitis:A case report

BACKGROUND Although cyclophosphamide(CPA)is the key drug for the treatment of autoimmune diseases including vasculitides,it has some well-known adverse effects,such as myelosuppression,hemorrhagic cystitis,infertility,and infection.However,CPA-associated severe enteritis is a rare adverse effect,and only one case with a lethal clinical course has been reported.Therefore,the appropriate management of patients with CPA-associated severe enteritis is unclear.CASE SUMMARY We present the case of a 61-year-old woman diagnosed with granulomatosis with polyangiitis based on the presence of symptoms in ear,lung,and,kidney with positive myeloperoxidase-antineutrophil cytoplasmic antibody.She received pulsed methylprednisolone followed by prednisolone 55 mg/d and intravenous CPA at a dose of 500 mg/mo.Ten days after the second course of intravenous CPA,she developed nausea,vomiting,and diarrhea,and was admitted to the hospital.Laboratory testing revealed hypoalbuminemia,suggesting proteinlosing enteropathy.Computed tomography revealed wall thickening of the stomach,small intestine,and colon with contrast enhancement on the lumen side.Antibiotics and immunosuppressive therapy were not effective,and the patient’s enteritis did not improve for>4 mo.Because her condition became seriously exhausted,corticosteroids were tapered and supportive therapies including intravenous hyperalimentation,replenishment of albumin and gamma globulin,plasma exchange,and infection control were continued.These supportive therapies improved her condition,and her enteritis gradually regressed.She was finally discharged 7 mo later.CONCLUSION Immediate discontinuation of CPA and intensive supportive therapy are crucial for the survival of patients with CPA-associated severe enteritis.

Prognosis of microscopic polyangiitis with renal involvement:report of 60 Chinese patients

With the widespread clinical application of renal biopsy and serum antineutrophil cytoplasmicantibody （ANCA） testing, the percentage of renal injuries caused by systemic small vessel vasculitis （ SVV ） including microscopic polyangiitis （ MPA ） and Wegener＇ s granulomatosis （WG） is on the rise in China. According to our previous report, SVV constituted 1.09% of diagnoses from all renal biopsies （5. 8% in secondary nephritis） and 14.4% of that from renal biopsies from patients with chronic renal failure,