Systemic lupus erythematosus: clinical and laboratory aspects related to age at disease onset

To analyse the clinical and laboratory parameters in patients with SLE according to their age at disease onset a retrospective study was undertaken of 272 Brazilian patients fulfilling the 1982 ARA criteria for SLE who were referred to the University Hospital of Campinas between 1973-1992.

The patients were divided into three groups according to their age at disease onset: Group A: under the age of 16 (39 patients); Group B age 17 to 49 (223 patients); Group C over the age of 50 (10 patients). Various clinical and laboratorial parameters were analysed and compared among these groups.

There were no significant differences in terms of race, time of disease onset or time of follow-up. Group A had more male patients than Groups B (p < 0.05) or C. Alopecia as an early manifestation, seizures and gastrointestinal involvement were more frequent in Group A (p < 0.05). Raynaud's phenomenon was lower in Group A than in Groups B and C (p < 0.05). Pericarditis was higher in Group C than in Groups A or B (p < 0.05). Nephrotic syndrome was lower in Group C than in Group A (p < 0.05). Positive LE cells were higher in Groups A and C than in Group B (p < 0.05). Anti-DNA antibodies were more prevalent in Group A than in B (p < 0.05). Anti-cardiolipin antibodies were more frequent in adult patients (p < 0.05) (Group B). The mortality rate was higher in Group A than in B or C (p < 0.05).

The clinical presentation and course of SLE may be influenced by the age at disease onset. Younger patients showed a poorer prognosis with more seizures, gastrointestinal involvement, nephrotic syndrome, and a higher rate of mortality than the other groups. Group A included more male patients and also exhibited more positive LE cells and anti-DNA antibodies. Raynaud's phenomenon was lower in these young patients. Elderly patients (C) presented more pericarditis and showed mild disease.