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Chapter 6: Disorders of the kidney 247

Age positive ANCA as well as anti-GBM antibodies, which
Young > old can cause a systemic vasculitis.
Chest X-ray may demonstrate pulmonary infiltrates

Sex due to haemorrhage.
M > F Pulmonary function tests may be performed to look
for increased transfer factor (evidence of alveolar
Aetiology/pathophysiology haemorrhage).
The pathogenic antibodies have been characterised as
IgGautoantibodies to the α3chain of type IV collagen.
Management
The response to the immune deposits is complement
Plasmapheresis is used to remove circulating anti-
activation, polymorph infiltration and a proliferative
GBM, and high dose steroids and cyclophosphamide
glomerulonephritis. Crescents form as a result of ep-
are used to switch off the production of antibody.
ithelial cell proliferation and monocyte infiltration into
Smoking, lung infection and pulmonary oedema all
Bowman’s space, causing rapidly progressive glomeru-
increase the risk of pulmonary haemorrhage.
lonephritis (RPGN).
If patients are dialysis dependent at presentation, and
have 100% crescents on renal biopsy, the chances of
Clinical features
renal recovery are poor. The decision to treat these
The usual presentation is of acute renal failure with

patients if they have no evidence of pulmonary haem-
oliguria, an active urine sediment with dysmorphic
orrhage or other vasculitis with aggressive therapy is
redblood cells, red cell casts and proteinuria.
difficult, as the risks of the above treatment are con-
Goodpasture’ssyndromeisdefinedasRPGNwithpul-

siderable.
monary haemorrhage. Symptoms include haemopty-
Anti-GBM disease only rarely relapses, so the cy-
sis, shortness of breath and symptoms of anaemia. Al-
clophosphamide can be stopped after 3 months, and
though this may occur in anti-GBM disease it is more
the steroids are tailed off.
commonly due to other causes (see Table 6.8).
Pulmonary haemorrhage is more common in patients

with underlying lung disease, lung infections, pul- Prognosis
monary oedema and in smokers. Patient survival and long-term renal function correlate
well with the degree of renal impairment at presenta-
Macroscopy/microscopy tion. Relapses occur particularly in those with ANCA
On renal biopsy there are diffuse global prolifera- and anti-GBM antibody, and it may occasionally recur
tive changes on light microscopy, often crescentic. after transplantation. Early diagnosis and treatment is
the key to reducing morbidity and mortality.
Immunofluorescence demonstrates linear IgG and C 3
deposits at the GBM.
Mesangiocapillary glomerulonephritis
Investigations
Initial investigation is as for acute renal failure and (membranoproliferative GN)
nephritic syndrome. Definition
Serum anti-GBM antibody can be detected by ra- MCGN (or MPGN) is a descriptive term for a pattern

dioimmunoassay (ELISA). Up to 40% of cases have a of glomerular disease with mesangial proliferation and
GBM thickening. It may be a primary disease (two types)
Table 6.8 Causes of Goodpasture’s syndrome but many cases are secondary (see Table 6.9).
ANCA-associated vasculitis including Wegener’s
granulomatosis Aetiology/pathophysiology
Anti-GBM disease (Goodpasture’s disease) Type I MCGN is almost certainly an immune complex
Concurrent ANCA and anti-GBM antibodies mediated disease, perhaps caused by an unknown in-
Systemic lupus erythematosus
fectious agent.