Patients with systemic lupus erythematosus are at significantly greater risk of pneumonia compared with the general population, particularly those with more severe disease and those with the FCGR2A HH genotype, a case-control study has shown.
Data from 232 patients with systemic lupus erythematosus (SLE) showed 15% had experienced one or more episodes of pneumonia – representing a standardized incidence ratio of 5.1 – while there were nearly four times as many patients with a Katz Severity Index equal to or greater than three among the cases compared with 196 controls.
Immunogenetic analysis revealed that the FCGR2A HH genotype was three times more common in SLE patients who experienced pneumonia compared with those who did not, according to a paper published online Aug. 1 in The Journal of Rheumatology (doi: 10.3899/jrheum.131470).
"Remarkably, only 6 patients (13%, 22% considering only pneumonia events after SLE diagnosis) were receiving immunosuppressive therapy at the time of pneumonia," wrote Dr. Iñigo Rúa-Figueroa and colleagues at Hospital Universitario de Gran Canaria Doctor Negrín, Las Palmas de Gran Canaria, Spain.
The study was supported by grants from the Ministerio de Economía y Competitividad, the European Regional Development Fund-European Social Fund, and the Sociedad Española de Neumología y Cirugía Torácica. Two of the investigators received grants from Universidad de Las Palmas de Gran Canaria, and one from the Ministerio de Economía y Competitividad. Hoffmann-La Roche provided funding for translation of the paper. The remaining authors had no relevant financial disclosures.