Seasonal variations in activity of systemic lupus erythematosus in a subarctic region

Abstract

Photosensitivity is one of the major clinical features of Systemic Lupus Erythematosus (SLE), and is considered to be implicated in the disease pathogenesis. We studied seasonal variations of SLE disease activity at latitude 70 degrees North where there is no sunlight in the winter time, in contrast to 24 h daily sunlight in the summer (midnight sun). The associations between the level of plasma melatonin in June and December with disease manifestations were also studied. Twenty-one SLE patients were examined each month for 1 y, and disease activity was assessed by laboratory parameters as well as clinical disease activity parameters SLEDAI and doctor's global assessment. Melatonin levels were quantified by a RIA-assay. There was no significant change of clinical measures or laboratory parameters of disease activity from one month to the next during the one year, except photosensitive rashes. January was the only month without SLE-flares or arthritis, in contrast to rest of the year. The levels of plasma melatonin were highest in December for seven patients and highest in June for one patient (P < 0.005). Plasma melatonin levels did not correlate with measures of clinical disease activity. At a latitude of 70 degrees North there were no major seasonal variations in SLE disease activity during the one year. There was an accumulation of photosensitivity in the summer months, but no indications of worsening of the disease in the winter months. In contrast to the rest of the year, there was no flare in January which had only 5.6 h of sunshine. The level of p-melatonin did not correlate with measures of disease activity.

Decreased Daily Melatonin Levels in Women with Systemic Lupus Erythematosus - A Short Report

“…A study in pineal melatonin deficient mice indicated that different immune cells and tissues were able to synthesise melatonin; thus, they could contribute to the detectable melatonin levels in these animals (28). In the present study, only daily melatonin concentrations were determined, as in other studies (24,29). Therefore, no information about the possible disturbances in the circadian melatonin rhythm was obtained, which was considered the main limitation of the study.…”

“…They did not correlate significantly with SLEDAI, arthritis, flare, C-reactive protein, anti-DNA or anti-nuclear antibodies in June and December, but correlated inversely with erythrocyte sedimentation rate (ESR) in December. The authors concluded that melatonin levels were not related to the clinical disease activity or manifestation, although the correlation with ESR may indicate some connection to SLE disease activity (24). Our study supported the latter assumption, although the two studies were difficult to compare: the Norwegian patients were recruited in the subarctic region with minimal winter sunlight, while our study was conducted in a region with a moderate climate and 80-100 average monthly hours of sunshine during the winter (25).…”

“…The first and only study of melatonin in humans with lupus was conducted by Haga et al (24). The authors examined seasonal variations in SLE activity as well as daily melatonin levels in lupus patients living in a subarctic region.…”

An evaluation of vitamin D status in individuals with systemic lupus erythematosus

“…A number of studies have investigated whether season contributes to flares of disease activity for individuals with SLE. One reported a significant increase in the European Consensus Lupus Activity Measure (ECLAM) during the spring with no worsening of disease activity during the summer (51) . Another identified a significant increase in disease activity scored by a clinical disease activity score during the winter compared to all other seasons (52) .…”

“…Some studies have shown an accumulation of photosensitivity (50,51) or a greater incidence of rash (52) during the summer months. However, lack of statistical analysis weakens these findings and the results should be interpreted with this in mind.…”