Outcome in glomerulonephritis due to systemic small vessel vasculitis: effect of functional status and non-vasculitic co-morbidity.
BACKGROUND
Previous studies in systemic vasculitis have defined a number of disease-specific factors including histological parameters and clinical vasculitis activity scores as outcome predictors. This study evaluates the previously neglected role of non-vasculitic factors in determining prognosis in this condition.


METHODS
We performed a retrospective study of all patients with a diagnosis of small vessel vasculitis (SVV) presenting with renal impairment to our service over a 12-year period.


RESULTS
Eighty-six patients were studied (median age 63.5 years, 64% male). Mean plasma creatinine at presentation was 533 micro M (6.3 mg/dl). Forty-seven patients (55%) required immediate dialysis, 21 (45%) recovered renal function on treatment. The presence of crescent fibrosis (P < 0.05) and interstitial fibrosis (P < 0.01) were significantly associated with a failure to recover renal function. There was a trend towards an increased relapse rate in those with a persistently positive ANCA result or a rising titre. Twelve month patient survival was 85.5% and 5-year survival was 63%. Factors independently associated with mortality were Karnofsky performance score at diagnosis (P < 0.00001), intensity of immunosuppressive treatment (P = 0.0007) and vasculitis classification (P = 0.009). Non-vasculitic co-morbidity was not independently associated with mortality. Patients who were, or became after treatment, dialysis-independent had a significant survival advantage (5-year survival 83 vs 42%, P = 0.001).


CONCLUSIONS
Non-vasculitic factors, particularly functional status as indicated by the Karnofsky performance score, play a major role in determining prognosis in SVV with renal involvement and should be an integral component of the decision making process when planning therapy, and in comparing outcomes between centres.
Little
Mark A
MA
Department of Nephrology, Lister Hospital, Stevenage, Herts, UK.
Nazar
Latiff
L
Farrington
Ken
K
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000032:analysis / Q000276:immunology*; D001327:Autoimmune Diseases / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D005921:Glomerulonephritis / Q000188:drug therapy / Q000453:epidemiology* / Q000276:immunology / Q000473:pathology*; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D017567:Karnofsky Performance Status; D008297:Male; D008875:Middle Aged; D011336:Probability; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D017678:Sex Distribution; D018709:Statistics, Nonparametric; D016019:Survival Analysis; D013997:Time Factors; D014657:Vasculitis / Q000188:drug therapy / Q000453:epidemiology* / Q000276:immunology / Q000473:pathology*
D019268:Antibodies, Antineutrophil Cytoplasmic; D007166:Immunosuppressive Agents