Persistent eosinophilia in rheumatoid arthritis: a prospective observational study

Area of Science:

• Rheumatology
• Immunology
• Infectious Diseases

Background:

• Eosinophilia is an infrequent finding in Rheumatoid arthritis (RA).
• Limited data exists on the association between eosinophilia and RA disease characteristics.
• Understanding the causes and implications of eosinophilia in RA is crucial.

Purpose of the Study:

• To prospectively investigate the clinical and disease-specific factors associated with eosinophilia in Rheumatoid arthritis patients.
• To identify the causes of eosinophilia in RA patients and assess the impact of treatment.

Main Methods:

• Prospective evaluation of RA patients with absolute eosinophil count ≥ 500/mm³.
• Investigation for parasitic infestation, with targeted therapy or empirical albendazole treatment.
• Comparison of disease-specific characteristics between RA patients with persistent eosinophilia and those without.

Main Results:

• Intestinal helminthiasis was identified as the most common cause (21%) of eosinophilia in this RA cohort.
• Eosinophilia resolved in approximately two-thirds of patients after empirical albendazole therapy.
• No significant difference in disease-related characteristics was observed between RA patients with persistent eosinophilia and those without.

Conclusions:

• Secondary causes, predominantly intestinal helminthic infections, account for most cases of eosinophilia in Rheumatoid arthritis patients.
• Empirical albendazole therapy can be effective in resolving eosinophilia of unknown origin in RA.
• Persistent eosinophilia in RA does not appear to indicate a more severe disease phenotype.