PREVALENCE OF ANCA IN PATIENTS WITH MULTI SYSTEM DYSFUNCTION AND LUNG PARENCHYMAL DISORDERS IN INTENSIVE CARE SETTINGS

Col. Dr. Vishal Marwaha; Dr.Pranav Raman Chickermane; Dr. Neeraj Sidharthan; Dr. Mithun C.B.; Dr. Bharat Pillai; Dr. Arun Tiwari; Dr. Vaishnavi Sujathen; Dr. Belinda Philip; Movva Hamsini

Volume : IX, Issue : XII, December - 2019

PREVALENCE OF ANCA IN PATIENTS WITH MULTI SYSTEM DYSFUNCTION AND LUNG PARENCHYMAL DISORDERS IN INTENSIVE CARE SETTINGS

Col. Dr. Vishal Marwaha, Dr. Pranav Raman Chickermane, Dr. Neeraj Sidharthan, Dr. Mithun C. B. , Dr. Bharat Pillai, Dr. Arun Tiwari, Dr. Vaishnavi Sujathen, Dr. Belinda Philip, Movva Hamsini

Abstract :

BACKGROUND– ANCA (Anti–neutrophil cytoplasmic antibody (ANCA)– associated vasculitides (AAV) present a diagnostic challenge to clinicians. They can be misdiagnosed if over reliance is placed on ANCA testing. This study has been done to assess the ANCA positivity in patients with multisystem dysfunction and lung parenchymal disorders, which often mimic AAV. METHODS– This prospective study was conducted from June 2007 to June 2010. A total of 100 patients– 50 each with multisystem dysfunction (MSD) and parenchymal lung diseases were included in the study. ANCA testing was done in all cases by indirect immunofluorescence (IIF) and enzyme–linked immune sorbent assay (ELISA), i.e., anti–proteinase 3 (anti–PR3) and anti–myeloperoxidase (anti– MPO). RESULTS– Of the 100 patients studied, two were diagnosed to have granulomatosis with polyangiitis (GPA). ANCA by IIF and anti–PR3 by ELISA were positive in one out of the 2 cases with GPA. Among the non– GPA cases (n= 98), 8 were false positive by IIF with all of them showing an atypical pattern. None of the 98 non–GPA cases was positive for anti–PR3 by ELISA while 4/98 of these cases were falsely positive for anti– MPO by ELISA. CONCLUSION– We found that cytoplasmic and perinuclear pattern on ANCA by IIF showed high specificity for AAV. False positive cases on ANCA by IIF showed an atypical pattern. ANCA (anti–PR3) by ELISA is very specific for vasculitis. ANCA (anti–MPO) by ELISA was found to be less specific for vasculitis. In the patient of GPA with positive anti–PR3, the anti–PR3 levels corroborated with disease activity. Tissue diagnosis still remains the gold standard.