Transcriptomic-based functional characterization of adverse events following lymphatic filariasis treatment

Intro: Lymphatic filariasis (LF) is a neglected tropical disease caused by the nematode parasite Wuchereria bancrofti. The primary tool used by the Global Program to Eliminate LF is mass drug administration (MDA), and some 500 million people take the medications each year. Mild to moderate adverse events (AEs) are common after LF treatment, and these pose a challenge for the LF elimination program. To better understand the pathogenesis of AEs, we studied patients from a LF treatment trial in Côte d'Ivoire. Method: Total RNA was extracted from peripheral blood leukocytes collected before and 24h after treatment (when AEs peak). Global RNA sequencing was performed for 9 individuals with systemic moderate AEs and for 9 matched controls without AEs. Differential gene expression analysis (DESeq) identified transcriptional signatures (TS) associated with post-treatment AEs. Results: Out of the 36 sequenced samples, the 9 post-treatment samples from subjects with AEs had a distinct TS (P=0.006 by clustering analysis); 744 genes were significantly upregulated in this group (post vs pre-treatment, paired). These genes were enriched for many biological pathways that included pro-inflammatory pathways such as TLR and NF-kappa B signaling. Genes upregulated in AEs were also significantly enriched for having STAT1/2/3 transcription factor binding sites indicating the importance for interferons in the AEs pathogenesis. Overall design: A total of 38 samples were sequenced (pre and post-treatment samples from 19 individuals. Ten of the individuals had adverse events (Aes) (9 with moderate Aes and 1 with mild Aes), and 9 individuals had no Aes. 16 samples were sequenced on HiSeq2000, and 22 samples were sequenced on HiSeq4000 (Illumina TruSeq Stranded Total RNA)