Collapsing glomerulopathy (CG) is a pathological entity seen as a collapse and wrinkling of glomerular tuft, podocyte dedifferentiation and hyperplasia. nephropathy, and lupus nephritis. Irrespective of the primary pathology, the presence of glomerular collapse portends a poor prognosis.[1] Till day, no case of CG in association with the anti-neutrophil cytoplasmic antibody (ANCA) connected vasculitis (AAV) has been explained. We hereby statement a case of CG that developed during the follow-up of a patient with AAV and biopsy verified pauci-immune glomerulonephritis. Case Statement A 41-year-old male presented with 3 months history of intermittent low grade fever, dry cough, pain, and swelling in small bones of hands, ft, and bilateral knees with no early morning stiffness. There was no history of top respiratory tract symptoms, hemoptysis, chest pain, shortness of breath, pedal edema, lower urinary tract symptoms, hematuria, abdominal pain, vomiting, loose stools, and headache or visual symptoms. In the 3rd month of illness, the patient developed nausea and vomiting and was admitted in local hospital. The evaluation exposed hemoglobin of 6.6 g/dl and serum creatinine of 4 mg/dl. His urine routine and microscopic exam showed 2 + proteinuria, 2C4 pus cells, and 10C12 erythrocytes. Further evaluation exposed positive antinuclear antibody and cytoplasmic ANCA (cANCA) by indirect immunofluorescence (IIF) and positive anti-proteinase 3 (anti-PR3) ANCA by enzyme-linked immune sorbent assay (ELISA). During the course of hospitalization, his serum creatinine risen to 9 mg/dl quickly, and he was initiated on hemodialysis. He was also provided two systems of packed crimson cell transfusion and three intravenous (i.v.) pulses of shot methylprednisolone (1 g each) before discussing our center for even more management. At presentation, he had a pulse rate of 92/min and his blood pressure was 150/90. He also had mild pallor, while other general and systemic examination was normal. He had a drop in SL 0101-1 hemoglobin from 9 g/dl to 7 g/dl over a period of 3 days; however, there was no associated hemoptysis. A high-resolution contrast tomography of the chest was done which showed patchy areas of dense, ground glass opacities in both lungs with septal thickening suggestive of alveolar hemorrhage. His repeat immunological work-up performed revealed 3+ cANCA positivity by IIF and anti-PR3 ANCA positivity by ELISA while the anti-glomerular basement membrane antibodies were negative. He continued to be oliguric with a serum creatinine of 7 mg/dl and was prescribed regular hemodialysis. Kidney biopsy revealed 12 glomeruli, of which three had cellular crescents and nine fibrocellular crescents along with glomerulitis. The underlying tuft was normal in three glomeruli while it was SL 0101-1 sclerosed in the rest. SL 0101-1 Tubules showed patchy acute injury and focal erythrocyte casts. The interstitium SL 0101-1 showed mild diffuse fibrosis and chronic inflammatory cell infiltration. Blood vessels did not show any FZD10 diagnostic abnormality. On immunofluorescence, the biopsy was negative for immunoglobulins and complement [Figure 1]. Figure 1 Photomicrograph showing fibrocellular crescents in the glomeruli with underlying normal tuft (H and E, 10) A diagnosis of AAV with pauci-immune crescentric glomerulonephritis and diffuse alveolar hemorrhage was made, and he was prescribed seven sessions of alternate day therapeutic plasma exchange (60 ml/kg), which was replaced with fresh frozen plasma and albumin. He was also given i.v. cyclophosphamide along with oral steroids 1 mg/kg/day. The dose of i.v. cyclophosphamide was according to his estimated glomerular filtration rate (eGFR). He received three doses of i.v. cyclophosphamide at 2 weekly intervals followed by next four doses at 3 weekly intervals. Oral steroids were continued at a dose of 1 1 mg/kg/day for 8 weeks, followed by gradual tapering to a dose of 5 mg/day at the end of 16 weeks. The patient responded to the treatment with a decline in serum creatinine to 1 1.8 mg/dl within 1-month of the treatment, which he continuing to keep up for next 4 months. Fourteen days following the last dosage of cyclophosphamide, he began developing worsening of.