Transcriptome analysis in acute gastrointestinal graft-versus host disease reveals a unique signature in children and shared biology with pediatric inflammatory bowel disease.

We performed transcriptomic analyses on freshly frozen (n=21) and paraffin-embedded (n=35) gastrointestinal (GI) biopsies from children with and without acute acute GI graft-versus-host disease (GvHD) to study differential gene expressions. We identified 164 significant genes, 141 upregulated and 23 downregulated, in acute GvHD from freshy frozen biopsies. CHI3L1 was the top differentially expressed gene in acute GvHD, involved in macrophage recruitment and bacterial adhesion. Mitochondrial genes were among the top downregulated genes. Immune deconvolution identified a macrophage cellular signature. Weighted gene co-expression network analysis showed enrichment of genes in the ERK1/2 cascade. Transcriptome data from 206 ulcerative colitis (UC) patients were included to uncover genes and pathways shared between GvHD and UC. Comparison with the UC transcriptome showed both shared and distinct pathways. Both UC and GvHD transcriptomes shared an innate antimicrobial signature and FCγ1RA/CD64 was upregulated in both acute GvHD (log-fold increase 1.7, P=0.001) and UC. Upregulation of the ERK1/2 cascade pathway was specific to GvHD. We performed additional experiments to confirm transcriptomics. Firstly, we examined phosphorylation of ERK (pERK) by immunohistochemistry on GI biopsies (acute GvHD n=10, no GvHD n=10). pERK staining was increased in acute GvHD biopsies compared to biopsies without acute GvHD (P=0.001). Secondly, plasma CD64, measured by enzyme-linked immunsorbant assay (n=85) was elevated in acute GI GvHD (P<0.001) compared with those without and was elevated in GVHD compared with inflammatory bowel disease (n=47) (P<0.001), confirming the upregulated expression seen in the transcriptome.

Phenotypes of adults with Fanconi anaemia.

The long-term outcomes of adults with Fanconi anaemia (FA) have improved with advances in haematopoietic stem cell transplantation (HSCT) and more detailed follow-up and screening guidelines. The phenotype of those who survive to adulthood may differ from the typical presentation of FA. We collected retrospective clinical data on adults with FA who received their care at the Cincinnati Children's Hospital Medical Center. In our final cohort of 52 patients, there were 29 females and 23 males, with median (range) age of 21 (18-37) years. Overall, 42 patients (81%) were alive at last follow-up. In all, 36 adults (69%) had undergone HSCT, including eight who had developed myelodysplasia or acute myeloid leukaemia. Eight (15%) developed squamous cell carcinoma. Endocrine complications were common, including hypothyroidism (42%), diabetes (10%), low body mass index (31%) and low bone mineral density (51%). The majority of adults with FA were employed (52%) or full-time students (13%). A significant subset of patients with FA are surviving into adulthood without requiring HSCT. Endocrine abnormalities and the development of solid tumours complicate adulthood. With improved survival outcomes following HSCT and more aggressive malignancy screening protocols, ongoing longitudinal analysis will be important to further characterise this cohort and the phenotype of untransplanted adults with FA.