Scleroderma renal crisis in a newly diagnosed mixed connective tissue disease resulting in dialysis-dependent chronic kidney disease despite angiotensin-converting enzyme inhibition.

Mixed connective tissue disease (MCTD) is a rheumatic disease with a combination of multiple connective tissue disorders, which includes dermatomyositis or polymyositis, systemic sclerosis, systemic lupus erythematosus, rheumatoid arthritis and Sjögren's syndrome. It affects various organs of the body, which includes the lungs, heart, kidneys, joints, muscles and the haematological system. Here, we report a case of MCTD consisting of scleroderma, Sjögren's syndrome and polymyositis complicated by scleroderma renal crisis (SRC) but with negative anti-nuclear antibody (ANA), anti-Scl 70 and anti-centromere antibodies. The patient was started on captopril for the treatment of SRC but developed chronic kidney disease despite adequate blood pressure control with angiotensin-converting enzyme inhibitor (ACEi).