Serologic profile and mortality rates of scleroderma renal crisis in Italy.
OBJECTIVE
To analyze clinical and serological characteristics of subjects with scleroderma renal crisis (SRC) in Italian patients with systemic sclerosis (SSc).


METHODS
A retrospective analysis of medical records from 9 Italian rheumatologic referral centers was carried out. All patients with SRC and an available serum sample at the time of crisis were included. Antinuclear antibodies (ANA) by indirect immunofluorescence, anti-topoisomerase (topo) I by enzyme-linked assay (ELISA), anti-RNA polymerases (RNAP) by ELISA for the subunit III, and immunoprecipitation (IP) were performed.


RESULTS
Forty-six cases (38 female; 40 diffuse cutaneous SSc) were identified. Mean age at SSc and SRC onset was 52.8 years +/- 13.2 and 55.4 years +/- 11.8, respectively. ANA were present in 44 patients (96%). Anti-topo I antibodies were detected in 30 (65%), anti-RNAP I-III in 7 (15%). No differences emerged between these 2 groups for their main clinical characteristics. The proportion of patients in the anti-RNAP I-III group developing SRC early (< 18 mo) in the course of SSc was significantly higher (p = 0.03). Cumulative survival rates were 64%, 53%, and 35% at 1, 2, and 10 years of followup, respectively. Survival rates of SSc patients significantly differed according to their autoantibody profile, being lower in the anti-topo I than in the anti-RNAP I-III group (p = 0.034).


CONCLUSION
SRC is a rare manifestation of SSc in Italy but it is still associated with severe prognosis. Anti-topo I reactivity was more frequent than anti-RNAP I-III in our patients with SRC and was associated with delayed onset and high mortality rates.