This case report involves a 77-year-old Chinese man admitted to our hospital for recurrent shortness of breath for more than 9 mo. The man was admitted to a local hospital for shortness of breath since February 2017. No clear diagnosis was made, and he was treated (the medication is unknown), but the symptom was recurrent. He felt worse and went to our hospital 2 mo later and was successively admitted to the Department of Cardiology and Respiratory. Laboratory examination showed mild renal insufficiency with serum creatinine (Scr) at 113 µmol/L. Anaemia with haemoglobin at 83 g/L, was present. Urinalysis revealed microscopic haematuria, but the urine protein was negative. Computed tomography (CT) of the chest showed right pleural effusion. For a correct diagnosis, the patient subsequently underwent thoracentesis and pleural biopsy. The hydrothorax was exudative, and the histological examination showed chronic inflammation. On the 14th day after admission, immunological tests revealed antinuclear antibodies (ANA) and anti-dsDNA antibody positivity, and myeloperoxidase (MPO)-antineutrophil cytoplasmic antibody (ANCA) was detected at 133 AU/mL using chemiluminescence. For further treatment, the patient went to a chest hospital and received nonspecific therapies. As his symptoms were not completely relieved in November 2017, he came to our hospital again. He had no history of coronary heart disease, metabolic disease, rheumatic disease, or liver disease, but had over 50 years of water pipes smoking history. He has no special personal and family history. His blood pressure, heart rate, and temperature were normal. A moderate anaemic appearance and decreased breathing sounds in the right lower lung were noted. Heart auscultation and abdominal examination were normal. No pitting oedema in the extremities was detected. He had no skin involvement, lymphadenopathy, or synovitis. On admission, serum laboratory results revealed the following values: Haemoglobin (Hb), 57 g/L; white blood cells, 5.9 × 109/L, platelets, 156 × 109/L; Scr, 310 µmol/L; serum albumin, 39 g/L; complement C3, 0.72 g/L; C4, 0.17 g/L; C-reactive protein, 32.1 mg/L. Liver function was normal. The patient was positive for ANA and anti-dsDNA antibodies. MPO-ANCA was detected at 180.62 AU/mL using chemiluminescence, and cANCA was positive by indirect immunofluorescence. Proteinase (PR3)-ANCA and pANCA were normal. We detected no anti-glomerular basement membrane or anti-phospholipase A2 receptor antibodies. Urinalysis revealed glomerular proteinuria (24-h urine protein, 0.887 g/d) and microscopic haematuria. CT of the chest showed right pleural effusion, and Doppler echocardiography indicated decreased left ventricular diastolic dysfunction and moderate pulmonary hypertension. Kidney ultrasound examination revealed normal-sized kidneys, renal cysts, and right kidney stones, with obstruction excluded. Lymph nodes or AVV was considered, leading us to perform a renal biopsy. Histological examination of the renal biopsy demonstrated 36 glomeruli, of which 13 were globally sclerotic and 14 were crescent, including 3 cellular, 1 fibro-cellular, 8 fibrous, 1 small cellular, and 1 small fibro-cellular, with some lesions of capillary fibrinoid necrosis. No marked mesangial cell proliferation, matrix proliferation, or fuchsinophilic protein deposits were found in the remaining glomeruli. Part of the interstitial region was infiltrated with inflammatory cells. Immunohistology showed negativity for immunoglobulin (Ig) M (+), IgA, IgG, C3, and C1q. Vacuolar degeneration in endothelial cells was observed by electron microscopy, and part of the glomerular capillary loops were compressed.