Clinical features and outcomes of anti-glomerular basement membrane disease in older patients.

BACKGROUND

Anti-glomerular basement membrane (GBM) disease is being recognized increasingly in older patients. Disease presentation and outcomes of these patients are unclear.

STUDY DESIGN

Case series.

SETTING & PARTICIPANTS: 221 consecutive Chinese patients with anti-GBM disease diagnosed in 1998-2008 in our tertiary referral center. Anti-GBM disease was defined as positive anti-GBM antibodies in circulation and/or linear immunoglobulin G deposition along the GBM on kidney biopsy.

PREDICTOR

Older age, defined as 65 years or older, and antineutrophil cytoplasmic antibody, detected using immunofluorescence and enzyme-linked immunosorbent assay, at presentation.

OUTCOMES

Clinical features, kidney pathologic characteristics, end-stage renal disease (ESRD), and mortality. Multivariate Cox proportional hazard models were used to assess the contribution of age, sex, clinical measures, and treatments to ESRD and mortality.

RESULTS

50 of 221 (22.6%) patients were 65 years or older. Older patients had a male predominance (male/female ratio, 1.9:1). They had a higher proportion of positive antineutrophil cytoplasmic antibody results (46.0% vs 14.6%; P < 0.001), lower prevalence of hemoptysis (26.0% vs 46.2%; P = 0.01), lower urine protein excretion (1.4 ± 1.0 vs 3.9 ± 3.3 g/d; P = 0.001), and higher estimated glomerular filtration rate (eGFR) at presentation (8.4 vs 5.1 mL/min/1.73 m(2); P = 0.007) compared with younger patients. During follow-up, 30 of 37 (81.1%) and 21 of 37 (56.8%) patients developed ESRD and died in the older group compared with 115 of 139 (82.7%) and 35 of 139 (25.2%) in the younger group (P = 0.1 and P = 0.001, respectively). For older patients, multivariate Cox regression analysis showed that higher initial eGFR was an independent predictor for both ESRD (HR, 0.86; 95% CI, 0.78-0.96; P = 0.005) and death (HR, 0.79; 95% CI, 0.66-0.94; P = 0.008).

LIMITATIONS

Not all patients underwent kidney biopsy, especially those with very old age or ESRD at presentation.

CONCLUSIONS

Older patients with anti-GBM disease had milder kidney damage and less pulmonary involvement. Outcomes were predicted by initial eGFR. Thus, early diagnosis was crucial to improve outcomes.