A 16-year-old girl developed pulmonary haemorrhage and acute renal failure requiring dialysis.
Investigations revealed:
Renal biopsy - Crescentic glomerulonephritis
Which one of the following antibodies is most likely to be found in the blood?
(Please select 1 option)
0. Anticardiolipin
0. Anticentromere
0. Antimitochondrial
0. Antimyeloperoxidase
0. Antinuclear
Answer : Antimyeloperoxidase
This patient manifests a pulmonary renal syndrome which is most commonly due to an anti-neutrophil cytoplasmic antibody test (ANCA) positive vasculitis and less commonly due to Goodpasture's syndrome (anti-glomerular basement membrane [GBM] antibodies).
ANCA antibodies are of two types:
C-ANCA which correlates with anti-proteinase 3 antibodies (PR3)
P-ANCA which correlates with anti-myeloperoxidase antibodies. P-ANCA/MPO antibodies are highly sensitive and specific for rapidly progressive glomerulonephritis and haemorrhagic alveolar capillaritis.
Anti-mitochondrial antibodies are found in primary biliary cirrhosis.
Anti-centromere antibodies are found in CREST/scleroderma syndrome.
ANA and anti-cardiolipin antibodies are found in systemic lupus erythematosus (SLE) which is not a cause of pulmonary renal syndrome.