Seasonal variation in the activity of systemic lupus erythematosus.
OBJECTIVE
To determine whether there is any seasonal variation in the activity of systemic lupus erythematosus (SLE) overall and by individual organs.


METHODS
The study group comprised 2102 patients with SLE who were followed in a prospective longitudinal cohort study. In this cohort, 92.3% of the patients were women. The mean ± SD age of the patients was 47.9 ± 13.9 years, 56.3% were white, 37.1% were African American, and 3.1% were Asian. Global disease activity was recorded by the Safety of Estrogens in Lupus Erythematosus National Assessment - Systemic Lupus Erythematosus Disease Activity Index (SELENA-SLEDAI) and the physician's global assessment. Activity of each organ was also recorded using SLEDAI terms and a visual analog scale (VAS; 0 to 3).


RESULTS
There was significant seasonal variation in photosensitive rash (p < 0.0001), which was more frequent in the spring and summer months (p < 0.0001). There was significantly more arthritis activity in spring and summer, as measured by both SELENA-SLEDAI (p = 0.0057) and the joint VAS (p = 0.0047). A decrease in renal activity was found in the summer months compared to the rest of the year (p = 0.0397). Serositis recorded by VAS had higher activity from August to October (p = 0.0392). Anti-dsDNA levels were significantly higher during October and November (p < 0.0001). There was significant seasonal variation in antiphospholipid antibody levels (p < 0.0001) and lupus anticoagulant (p = 0.0003). We found a significant variation in activity through the year in global disease activity as measured by SELENA-SLEDAI (p = 0.048).


CONCLUSIONS
In the Hopkins Lupus Cohort, skin and joint activity is increased during the spring and summer, but other organs have different patterns. These seasonal variations likely reflect environmental factors that influence disease activity, including ultraviolet light and infections.
Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
Alí
A
Duarte-García
Hong
H
Fang
Chi Hung
CH
To
Laurence S
LS
Magder
Michelle
M
Petri
D000328:Adult; D000974:Antibodies, Antinuclear / Q000097:blood / Q000276:immunology; D017152:Antibodies, Antiphospholipid / Q000097:blood / Q000276:immunology; D018771:Arthralgia / Q000097:blood / Q000276:immunology / Q000503:physiopathology; D001168:Arthritis / Q000097:blood / Q000276:immunology / Q000503:physiopathology; D005076:Exanthema / Q000097:blood / Q000276:immunology / Q000503:physiopathology; D005260:Female; D006801:Humans; D007668:Kidney / Q000276:immunology / Q000502:physiology / Q000503:physiopathology; D016682:Lupus Coagulation Inhibitor / Q000097:blood / Q000276:immunology; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000276:immunology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010787:Photosensitivity Disorders / Q000097:blood / Q000276:immunology / Q000503:physiopathology; D011446:Prospective Studies; D012621:Seasons; D012700:Serositis / Q000097:blood / Q000276:immunology / Q000503:physiopathology; D012720:Severity of Illness Index
D000974:Antibodies, Antinuclear; D017152:Antibodies, Antiphospholipid; D016682:Lupus Coagulation Inhibitor