POS-139 AN ATYPICAL PRESENTATION OF DUAL-POSITIVE ANTI-MYELOPEROXIDASE AND ANTI-GLOMERULAR BASEMENT MEMBRANE ANTIBODIES VASCULITIS WITH PULMONARY-RENAL SYNDROME : A CASE REPORT

ABSTRACT

Introduction: Double-positive vasculitis with anti-polynuclear cytoplasm (ANCA) and anti-glomerular basement membrane (GBM) antibodies is a rare entity of systemic vasculitis defined by the presence of ANCA and anti-GBM antibodies. Methods: We report a rare case of pulmonary-renal syndrome with atypical clinical presentation. Results: A 52 year-old smoking man with a history of exposure to hydrocarbons and uretheral lithiasis, presented in April 2021 epigastralgia and vomiting. the investigations concluded to H.pylori gastritis and ulcer and he received a quadruple therapy. The kidney function was correct in April 2021. The evolution was marked by the persistence of symptoms and urine output had decreased for a few days. He was found to have renal dysfunction (serum creatinine 2000 µmol/L). Abdominal CT scan without iodinated contrast injection showed severe hydronephrosis of the right pelvicalyceal system with cortical thinning and dilatation of the right ureter. The two kidneys had regular outlines seat multiple bilateral renal cysts with exophytic development. He had a nephrosomy with secondarily a right double-J stent with slight improvement of renal function. The patient presented then with acute respiratory distress.Testing for COVID-19 PCR and serology were negatives. Chest CT scan showed alveolar syndromeevoking pulmonary overload. No pneumopathy covid was shown. The evolution was marked by the non improvement by depletion and he developed hemoptic sputum and low-abundance epistaxis. The attitude was non-invasive ventilation and broad-spectrum antibiotics therapy. Control chest CT showed emphysematous lung with signs of fibrosis with bilateral subpleural nodules. A rereading of the scanner showed intraalveolar hemorrhage which has regressed on the imaging of the control. Based on these data, pneumo renal syndrome was suspected and a bronchoscopy was performed showing alveolar hemorrhage with 70% siderophageswith Gold score superior to 100. Anti-GBM and p-ANCA and antibodies were positive at a high titer. Electroneuromyogram was without anomaly. Kidney biopsy was not done because of the presence of multiple cysts. The patient received pulse methylprednisone for three days followed by oral prednisone and underwent eleven sessions of plasmapheresis. Intraveinous Cyclophosphamide has been started. He showed remarkable recovery as his lung fields cleared with negativity of GBM antibodies. Kidney function didn't improved and he remained dependent on dialysis. Conclusions: Our observation is exceptional since the clinical and radiological presentation of the patient was not that of a pulmonary-renal syndrome. The elements of this syndrome have in fact been masked by the obstacle on the urinary tract on one hand and the hypothesis of a covid19 pneumonia on the other hand in the face of the epidemiological context. Atypical feature of pulmonary renal syndrome should be kept in mind to avoid diagnostic and treatment delays. No conflict of interest