A 13-year-old girl presented with a 2-month history of pallor, lethargy, cough with bloody sputum and shortness of breath. On specific questioning, she had an intermittent fever. There was no joint pain, alopecia, mouth ulcers, rashes or Raynaud's. At the time of admission, she was on no regular medications. There was no family history of rheumatological disease.The patient immigrated from Korea 1 year ago. Systematic enquiry revealed an episode of anaemia at the age of 3-4 years for which no cause was found. She was treated with iron for 2 years. She suffered several episodes of cough and haemoptysis in the previous 4 years, and on each occasion was diagnosed as pneumonia. On one occasion, the patient had required ventilation for 3 weeks. During this admission, she was treated with antibiotics. She went on to make a full recovery.Initial investigations revealed haemoglobin 65 g/L, platelets 244 ¥ 10 9 /L and white cell count 5 ¥ 10 9 /L. Erythrocyte sedimentation rate (ESR) 65 mm/h and C-reactive protein <3. Renal and liver function tests were normal apart from a raised bilirubin 59 mmol/L (<21). Haemaglobinopathy screen, a-globin gene deletion studies and glucose-6-phosphate dehydrogenase screen were all negative. The direct Coombs test antiimmunoglobin G was weakly positive and haptoglobins were low (<0.07). Anti-nuclear antibody (ANA) was positive (>1:1280) with positive Ro antibodies. Double-stranded DNA, anti-neutrophil cytoplasmic antibodies and anti-glomerular basement membrane antibodies were negative. Rheumatoid factor was positive at 113 IU/mL (<30). C3 and C4 were low; C3 0.75 g/L (normal 0.9-1.8), C4 < 0.05 g/L (normal 0.1-0.4). Immunoglobin M anti-cardiolipin antibodies were weakly positive at 31 (<20) and lupus anticoagulant was negative. There was a polyclonal increase in immunoglobin G. Mycoplasma, hepatitis B, C and HIV serology were all negative. Urine sediment was normal.Chest X-ray (CXR) demonstrated diffuse airspace opacity and high-resolution computed tomography of the chest showed moderately extensive bilateral ground glass opacification throughout all zones of both lungs with relative sparing of the extreme lung bases consistent with diffuse alveolar haemorrhage (Fig. 1). Lung function tests were restrictive with the forced expiratory volume in the first second/forced vital capacity ratio of 84% and a forced vital capacity of 2.52 L (74% predicted). This was confirmed with measurement of her total lung capacity 3.47 L (78%) and her diffusing capacity of the lung for carbon monoxide (DLCO) corrected for haemoglobin of 14.5 (61% predicted). Blood gas on room air revealed a pH 7.38, PaO 2 59 mmHg, PaCO2 38 mmHg, bicarbonate 28 mmol/L. An open lung biopsy was performed; specimens were negative for mycobacterium tuberculosis, legionella and fungi. Histology revealed diffuse alveolar haemorrhage with haemosiderin-laden macrophages. There was no evidence of vasculitis, capillaritis or granulomatous inflammation (Fig. 1). A diagnosis of systemic lupus erythematosus (SLE) was made. She was transfu...