Pauci-immune (pauci- Latin: few, little) vasculitis is a form of vasculitis that is associated with minimal evidence of hypersensitivity upon immunofluorescent staining for IgG.^[1] Often, this is discovered in the setting of the kidney.

When the glomeruli of the kidney from a patient with symptoms of proliferative nephritis are examined under the microscope, crescents will be normally observed. When these are subjected to immunofluorescence, three patterns can be observed: linear, granular and negative (pauci-immune).^[1] The linear and granular patterns are examples of positive immunofluorescence that are associated as follows: Goodpasture syndrome (linear pattern), post-streptococcal glomerulonephritis (granular), and diffuse proliferative nephritis (granular).^[1] The negative immunofluorescence pattern, however, is called "pauci-immune" and is often associated with systemic vasculitides (plural of vasculitis) including: microscopic polyangiitis, eosinophilic granulomatosis with polyangiitis (EGPA), and granulomatosis with polyangiitis (GPA).^[1][2]

In the setting of systemic vasculitis as described above, proliferative nephritis is associated with antineutrophil cytoplasmic antibodies (ANCA).^[3] Because of this, an ANCA test should always follow a negative immunofluorescence result to have the highest accuracy for confirming pauci-immune vasculitis-driven proliferative nephritis.^[1]

Some cases of pauci-immune proliferative nephritis have no explanation and are thus deemed "idiopathic."

Peak incidences in 50- to 60-year-olds symptoms include intermittent fever / weight loss / shortness of breath / joint pain.

• Systemic vasculitis#Pauci-immune
• Goodpasture Syndrome and Poststrep Glomerulonephritis
• Microscopic polyangiitis, Eosinophilic granulomatosis with polyangiitis or Granulomatosis with polyangiitis

• wikt:paucity