The following are the most important diseases or complications that may be contributed to by microscopic polyangiitis (MPA):
Respiratory system (J00-J99)
- Pulmonary syndrome – combination of renal and pulmonary vasculitis (inflammation of the (mostly) arterial blood vessels in the kidneys and lungs) including necrotizing extracapillary proliferative glomerulonephritis (inflammation of the glomeruli (renal corpuscles) of the kidneys).
Musculoskeletal system and connective tissue (M00-M99).
- Capillaritis of the lung with alveolar hemorrhage syndrome (hemorrhage).
Genitourinary system (kidneys, urinary tract – reproductive organs) (N00-N99).