Part 1

A 79-year-old retired Indian shopkeeper presented with a 7-month history of weight loss, anorexia, early satiety and lumbosacral back pain. He had type 2 diabetes mellitus complicated by nephropathy (baseline creatinine 92 μmol/l), bilateral cataracts, osteoporosis, vitamin B12 deficiency and a past history of pulmonary tuberculosis. Family history was unremarkable. He was an ex-smoker of 100 pack years, and did not drink alcohol. Regular medications included metformin, simvastatin, aspirin, alendronate and vitamin B12 injections. Physical examination revealed generalised muscle wasting, but no other stigmata of chronic disease.

Laboratory investigations showed a creatinine of 178 μmol/l (normal range 66–112) and a raised C-reactive protein of 61 mg/l (normal range 0–5). Complement 3 and 4 levels were normal; antineutrophil cytoplasmic antibody …