La fibromialgia con factor reumatoide elevado se asocia a mala respuesta terapéutica pero no con progresión a artritis reumatoide. Estudio de cohortes prospectivo

Abstract

Objective

Evaluate response to treatment and progression to rheumatoid arthritis (RA) in patients with fibromyalgia (FM) associated with elevated rheumatoid factor (RF).

Material and methods

Prospective cohort study. The sample consisted of 124 patients with FM: 62 with high RF (> 20 U/ml) and 62 with negative RF (0-20 U/ml). All patients were evaluated using FM treatment improvement score (FIQR) and progression to RA according to EULAR/ACR 2010 criteria at 6 and 12 months. Pearson's χ² test for homogeneity was used to relate variables of improvement to FM treatment and progression to RA.

Results

The response to treatment was lower in the high RF group (24 and 20 patients improved at 6 and 12 months, respectively, compared to 45 and 38 patients in the negative RF group), with a significant difference. Progression to rheumatoid arthritis was similar in both groups (5 in the high RF group and 4 in the negative RF group), with a non-significant relationship.

Conclusions

FM with elevated RF is associated with a poor therapeutic response but not with progression to RA.