Elevated IgA and IL-10 levels in very-early-onset inflammatory bowel disease secondary to IL-10 receptor deficiency / Níveis elevados de IgA e IL-10 na doença inflamatória intestinal de início muito precoce secundária à deficiência do receptor de IL-10

ABSTRACT Objective: To report two patients with very-early-onset inflammatory bowel disease (VEOIBD) secondary to interleukin-10 receptor (IL-10R) mutations, explore immunophenotyping data and plasma cytokine profile on these cases compared to healthy controls, and describe the phenotype of IL-10/IL-10R mutations based on a literature review. Case description: We report on two female infants referred to our tertiary center at the age of ten months, with severe colonic and perianal disease, as well as significant malnutrition, who had shown limited response to usual inflammatory bowel disease (IBD) therapy agents. In the first case, whole-exome sequencing (WES) revealed a homozygous (c.537G>A/p.T179T) mutation in exon 4 of the IL-10RA gene, while in the second patient, compound heterozygosity was identified, also in the IL-10RA gene (chr11:117.859.199 variant A>G/p.Tyr57Cys and chr11: 117.860.335 variant G>T/p.Val123Leu). Both patients underwent hematopoietic cell transplantation (HCT). Immunological work-up of these patients revealed increased IL-10 plasma levels and increased IgA. Comments: Our case reports disclose novel findings on plasma cytokine profile in IL-10R deficiency, and we describe the severe phenotype of IL-10/IL-10R deficiency that should be recognized by physicians.

RESUMO Objetivo: Relatar os casos de duas pacientes com doença inflamatória intestinal de início muito precoce (em inglês VEOIBD) secundária a mutações do receptor de interleucina 10 (IL-10R), explorar dados de imunofenotipagem e perfil de citocinas plasmáticas nesses casos em comparação com indivíduos saudáveis e descrever o fenótipo de mutações IL-10/IL-10R com base em uma revisão da literatura. Descrição do caso: Duas lactentes do sexo feminino foram encaminhadas ao nosso centro terciário, ambas com dez meses no momento do encaminhamento, com doença colônica e perianal grave, bem como desnutrição significativa, tendo uma resposta limitada aos agentes de terapia usuais de doença inflamatória intestinal (DII). No primeiro caso, o sequenciamento completo do exoma revelou mutação homozigótica (c. 537G>A/p.T179T) no exon 4 do gene IL-10RA, enquanto no segundo caso heterozigosidade composta foi identificada também no gene IL-10RA [chr11: 117.859.199 - variante A>G/p.Tyr57Cys e chr11: 117.860.335 - variante G>T/ p.Val123Leu]. Ambas as pacientes foram submetidas a Transplante de Células-Tronco Hematopoiéticas. A investigação imunológica das pacientes revelou aumento dos níveis plasmáticos de IL-10 e aumento da IgA. Comentários: Nossos relatos de casos descrevem novos achados no perfil de citocinas plasmáticas na deficiência de IL-10R, e relatamos o fenótipo grave da deficiência de IL-10/IL-10R que deve ser reconhecido pelos médicos.

Elevated IgA and IL-10 levels in very-early-onset inflammatory bowel disease secondary to IL-10 receptor deficiency.

OBJECTIVE: To report two patients with very-early-onset inflammatory bowel disease (VEOIBD) secondary to interleukin-10 receptor (IL-10R) mutations, explore immunophenotyping data and plasma cytokine profile on these cases compared to healthy controls, and describe the phenotype of IL-10/IL-10R mutations based on a literature review. CASE DESCRIPTION: We report on two female infants referred to our tertiary center at the age of ten months, with severe colonic and perianal disease, as well as significant malnutrition, who had shown limited response to usual inflammatory bowel disease (IBD) therapy agents. In the first case, whole-exome sequencing (WES) revealed a homozygous (c.537G>A/p.T179T) mutation in exon 4 of the IL-10RA gene, while in the second patient, compound heterozygosity was identified, also in the IL-10RA gene (chr11:117.859.199 variant A>G/p.Tyr57Cys and chr11: 117.860.335 variant G>T/p.Val123Leu). Both patients underwent hematopoietic cell transplantation (HCT). Immunological work-up of these patients revealed increased IL-10 plasma levels and increased IgA. COMMENTS: Our case reports disclose novel findings on plasma cytokine profile in IL-10R deficiency, and we describe the severe phenotype of IL-10/IL-10R deficiency that should be recognized by physicians.

Phenotypes of STAT3 gain-of-function variant related to disruptive regulation of CXCL8/STAT3, KIT/STAT3, and IL-2/CD25/Treg axes.

STAT3 is a cytokine-signaling transcription factor critical for gene regulation. Gain-of-function (GOF) mutations in STAT3 are associated with lymphoproliferation, autoimmune cytopenias, increased susceptibility to infection, early-onset solid-organ autoimmunity, short stature, and eczema. We studied the JAK/STAT signaling pathway gene expression and the cytokine profile in two families carrying STAT3-GOF variants to shed light on the STAT3-GOF-associated variable expressivity, including the identification of disease markers. Considering 92 target genes, KIT and IL2RA were downregulated only in patients with high clinical penetrance, while CXCL8 was markedly downregulated for all of them. Unlike previous studies, SOCS3-a STAT3 inhibitor-was not upregulated in patients. In addition, low levels of IL-2 and a reduced numbers of Tregs cells were strikingly prevalent in patients. This study shows a disruptive role of STAT3-GOF variants in the regulatory axis activities CXCL8/STAT3, KIT/STAT3, IL2/CD25/Treg, which, by slightly different mechanisms, underlie the broad clinical spectrum seen in the studied patients. In addition, we suggest the investigation of CXCL8 as a biomarker for identifying STAT3-GOF mutation.

Differential regulation of miR-146a/FAS and miR-21/FASLG axes in autoimmune lymphoproliferative syndrome due to FAS mutation (ALPS-FAS).

Most cases of autoimmune lymphoproliferative syndrome (ALPS) have an inherited genetic defect involving apoptosis-related genes of the FAS pathway. MicroRNAs (miRNAs) are a class of small non-coding regulatory RNAs playing a role in the control of gene expression. This is the first report on miRNAs in ALPS patients. We studied a mother and son carrying the same FAS cell surface death receptor (FAS) mutation, but with only the son manifesting the signs and symptoms of ALPS-FAS. The aim was to analyse, by reverse transcription-quantitative polymerase chain reaction (RT-qPCR), the peripheral blood mononuclear cells (PBMC) relative expression of miR-146a and miR-21, including their passenger strands and respective targets (FAS and FASLG). In comparison with healthy matched control individuals, miR-21-3p was over-expressed significantly (P = 0·0313) in the son, with no significant change in the expression of miR-146a, miR-146a-3p and miR-21. In contrast, the mother had a slight under-expression of the miR-146a pair and miR-21-3p (P = 0·0625). Regarding the miRNA targets, FAS was up-regulated markedly for the mother (P = 0·0078), but down-regulated for the son (P = 0·0625), while FASLG did not have any significant alteration. Taken together, our finding clearly suggests a role of the miR-146a/FAS axis in ALPS-FAS variable expressivity in which FAS haploinsufficiency seems to be compensated only in the mother who had the miR-146a pair down-regulated. As only the son had the major clinical manifestations of ALPS-FAS, miR-21-3p should be investigated as playing a critical role in ALPS physiopathology, including the development of lymphoma.