Choroidal Thickness Changes in Rheumatoid Arthritis and the Effects of Short-term Hydroxychloroquine Treatment

Purpose: The objective of this study is to evaluate choroidal thickness (CT) in patients with rheumatoid artritis (RA) and the effects of short-term hydroxychloroquine (HCQ) treatment.

Methods: Thirty RA patients (group 1) and 30 normal subjects (group 2) were enrolled in the study. Group 1 was further divided into two subgroups as follows: group 1A (Before HCQ treatment) and group 1B (1 year after HCQ treatment). The CTs were measured using optical coherence tomography (EDI-OCT).

Results: The mean subfoveal choroidal thickness (SFCT) (µm) was 335.70 ± 64.58 in group 1A, 341.85 ± 63.95 in group 1B, and 358.51 ± 63.83 in group 2. SFCT was significantly lower in groups 1A and 1B than in group 2 (p = 0.020 and p = 0.028, respectively). Group 1B presented statistically significant thicker SFCT than group 1A (p = 0.033).

Conclusions: CT was significantly lower in RA patients than in normal subjects. HCQ treatment may, however, cause a statistically significant increase in SFCT. This increase is clinically negligible.     

Evolutionary evidence of the effect of rare variants on disease etiology

Gorlov IP, Gorlova OY, Frazier ML, Spitz MR, Amos CI. Evolutionary evidence of the effect of rare variants on disease etiology. The common disease/common variant hypothesis has been popular for describing the genetic architecture of common human diseases for several years. According to the originally stated hypothesis, one or a few common genetic variants with a large effect size control the risk of common diseases. A growing body of evidence, however, suggests that rare single‐nucleotide polymorphisms (SNPs), i.e. those with a minor allele frequency of less than 5%, are also an important component of the genetic architecture of common human diseases. In this study, we analyzed the relevance of rare SNPs to the risk of common diseases from an evolutionary perspective and found that rare SNPs are more likely than common SNPs to be functional and tend to have a stronger effect size than do common SNPs. This observation, and the fact that most of the SNPs in the human genome are rare, suggests that rare SNPs are a crucial element of the genetic architecture of common human diseases. We propose that the next generation of genomic studies should focus on analyzing rare SNPs. Further, targeting patients with a family history of the disease, an extreme phenotype, or early disease onset may facilitate the detection of risk‐associated rare SNPs.