Validation of the Draft Classification Criteria of Granulomatosis with Polyangiitis (GPA) Amongst Indian Patients with ANCA Associated Vasculitis

Aman Sharma¹, Adarsh MB², GSRSNK Naidu³, Manish Rathi⁴, Kusum Sharma⁵, Varun Dhir⁶, Ritambhra Nada⁷, Ranjana Minz⁸ and Sanjay Jain⁹, ¹Clinical Immunology and Rheumatology Services, Department of Internal Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India, Chandigarh, India, ²Internal Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India, Chandigarh, India, ³PGIMER, cHANDIGARH, India, ⁴Department of Nephrology,, Postgraduate Institute of Medical Education and Research, Chandigarh, India, ⁵Department of Medical Microbiology,, PGIMER,, Chandigarh, India, ⁶Internal Medicine (Rheumatology Unit), Postgraduate Institute of Medical Education and Research, Chandigarh, India, Chandigarh, India, ⁷Postgraduate Institute of Medical Education and Research, Chandigarh, India, ⁸Department of Immunopathology,, PGIMER,, Chandigarh, India, ⁹Postgraduate Institute of Medical Education and Research, Chandigarh, India, CHANDIGARH, India

Meeting: 2018 ACR/ARHP Annual Meeting

Keywords: classification criteria and vasculitis, Wegener's granulomatosis

Session Information

Date: Tuesday, October 23, 2018

Title: Vasculitis – ANCA-Associated Poster II

Session Type: ACR Poster Session C

Session Time: 9:00AM-11:00AM

Background/Purpose: A draft classification criteria of GPA was proposed at ACR meeting in San Diego in 2017. The present criteria is a modification of ACR/EULAR provisional 2017 classification criteria for GPA presented at ACR Washington meeting in 2016. This has been a result of data driven DCVAS study.The purpose of the present study was to validate the recently proposed draft classification criteria of GPA in a real life cohort of ANCA associated vasculitis (AAV).

Methods:

The draft GPA criteria was applied to patients diagnosed to have AAV according to European Medicines Agency (EMA) algorithm. The level of agreement between the draft GPA criteria and EMA algorithm was assessed using Cohen’s kappa. The level of agreement between the ACR/EULAR provisional 2017 classification criteria for GPA and EMA algorithm was also assessed using Cohen’s kappa. Sensitivity and specificity of the draft GPA criteria and the ACR/EULAR provisional 2017 classification criteria for GPA was calculated taking EMA algorithm as gold standard.

Results: 224 patients with mean age of 41.7±15.0 years were included. Female: male ratio was 1.3:1. ANCA by IIF was done in all patients and was positive in 171(cANCA -125, pANCA -46). PR3/MPO ELISA was available in 125 patients (PR3-93, MPO- 32).Using EMA algorithm EGPA was diagnosed in 6, GPA in 187 and MPA in 31. With ACR 1990 criteria, GPA was diagnosed in 137 patients while with draft GPA criteria 136 were classified as GPA. Draft GPA criteria had fair agreement with EMA (kappa-0.23, sensitivity-66%% and specificity-70%) than ACR criteria(kappa 0.1, sensitivity -64% and specificity-45%).ACR/EULAR provisional 2017 classification criteria for GPA also had a fair agreement with EMA(kappa 0.26,sensitivity -69.5% and specificity-70.2%).Eleven of thirty one MPA patients were reclassified as GPA by draft GPA criteria. 5 patients who were classified as GPA by EMA and ACR/EULAR provisional 2017 classification criteria for GPA were excluded by the new criteria. All of them were MPO positive and had pulmonary nodules and paranasal sinus involvement.

Conclusion: Within the limits of a retrospective design, the study showed fair agreement of draft GPA criteria with EMA algorithm. The specificity of the new criteria compared to EMA algorithm is low, likely due to the stress given to PR3/cANCA positivity.

Table 1. Reclassification of various AAV patients (EMA and ACR 1990) by draft GPA criteria

ANCA associated vasculitis	No. of patients (n=224, %,)	Reclassified as GPA by ACR/EULAR 2018 criteria
ACR 1990 GPA	137(61.1)	89
EMA GPA	187(83.4)	125
EMA MPA	31(13.8)	11
EMA EGPA	6(2.6)	0

Disclosure: A. Sharma, None; A. MB, None; G. Naidu, None; M. Rathi, None; K. Sharma, None; V. Dhir, None; R. Nada, None; R. Minz, None; S. Jain, None.

To cite this abstract in AMA style:

Sharma A, MB A, Naidu G, Rathi M, Sharma K, Dhir V, Nada R, Minz R, Jain S. Validation of the Draft Classification Criteria of Granulomatosis with Polyangiitis (GPA) Amongst Indian Patients with ANCA Associated Vasculitis [abstract]. Arthritis Rheumatol. 2018; 70 (suppl 9). https://acrabstracts.org/abstract/validation-of-the-draft-classification-criteria-of-granulomatosis-with-polyangiitis-gpa-amongst-indian-patients-with-anca-associated-vasculitis/. Accessed .

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