Clinical, serologic, and immunogenetic characterization (HLA-DRB1) of late-onset lupus erythematosus in a Colombian population.

BACKGROUND

Late-onset systemic lupus erythematosus (SLE) represents a specific subgroup that is defined as onset after 50 years of age. Late-onset lupus may have a different clinical course and serological findings, which may delay diagnosis and timely treatment.

OBJECTIVE

The objective of this paper is to determine the clinical, serologic, and immunogenetic differences among Colombian patients with late-onset SLE versus conventional SLE patients.

METHODS

This was a cross-sectional study in a Colombian population. Patients and their medical records were analyzed from the services of Rheumatology in Bogotá and met the criteria for SLE, according to the American College of Rheumatology (ACR) revised criteria for the classification of SLE.In a reference group of late-onset SLE patients (98 participants, with an onset after 50 years of age) and a group of conventional SLE patients (72 participants, with an onset of age of 49 years or less), multiple clinical variables (age, clinical criteria for lupus, alopecia, weight loss, fever, Raynaud's phenomenon) and multiple serological variables (blood count, blood chemistry profile, autoantibodies) were analyzed. Additionally, the HLA class II (DRB1) of all the patients was genotyped, including an additional group of patients without the autoimmune disease. Statistical analysis was performed using the STATA 10.0 package.

RESULTS

In the group of late-onset lupus, there was a higher frequency of pleurisy (p = 0.002), pericarditis (p = 0.026), dry symptoms (p = 0.029), lymphopenia (p = 0.007), and higher titers of rheumatoid factor (p = 0.001) compared with the group of conventional SLE. Late-onset SLE patients had a lower seizure frequency (p = 0.019), weight loss (p = 0.009), alopecia (p < 0.001), and Raynaud's phenomenon (p = 0.013) compared to the conventional SLE group. In late-onset SLE, HLA DR17 (DR3) was found more frequently compared with individuals without autoimmune disease (OR 3.81, 95% CI 1.47 to 10.59) (p = 0.0016).

CONCLUSIONS

In the Colombian SLE population analyzed, there may be a probable association of several clinical and serologic variants, which would allow the differentiation of variables in the presentation of the disease among patients with late-onset SLE vs. conventional SLE.