Safety of performing classical versus low transverse caesarean sections in extremely preterm and very preterm births: Maternal and neonatal complications.

AIMS: Improved survivability of extremely preterm infants has led to increased rates of caesarean sections. Short-term maternal and neonatal risks of classical caesarean sections (CCS) in the context of extreme prematurity remain unclear. The aim was to examine maternal and neonatal complications associated with CCSs versus low transverse caesarean sections (LTCS) at extremely preterm (23 0/7-27 6/7 weeks) and very preterm gestational ages (28 0/7-31 6/7 weeks). METHODS: A retrospective cohort study was conducted at Royal Brisbane and Womens Hospital, Queensland, Australia between 2016 and 2020. Maternal and neonatal outcomes were examined using univariate and multivariate statistical analysis. RESULTS: CCSs (extremely preterm: n = 93; very preterm: n = 83) were associated with higher estimated blood loss than LTCS (extremely preterm: n = 70; very preterm: n = 287) in very preterm births (CCS: 638 ± 410 mL; LTCS: 556 ± 397 mL; P = 0.01). There was no significant difference in composite maternal outcomes between CCS and LTCS for extremely preterm (adjusted odds ratio (aOR): 1.11; 95% confidence interval (CI): 0.58-2.12; P = 0.75) or very preterm births (aOR: 1.08; 95% CI: 0.63-1.94; P = 0.79) after accounting for multiple pregnancy, placenta accreta and non-cephalic fetal presentations. Although CCSs were associated with lower Apgar scores at 1 min post-birth than LTCSs at very preterm gestational ages (CCS: 5.58 ± 2.10; LTCS: 6.25 ± 2.14; P = 0.02), there was no statistical difference in the rates of intraoperative neonatal injuries or composite outcomes when corrected for low birth weight. CONCLUSION: Short-term maternal and neonatal outcomes do not significantly differ between CCS and LTCS for extremely preterm or very preterm births.

Genetic association of ankylosing spondylitis with TBX21 influences T-bet and pro-inflammatory cytokine expression in humans and SKG mice as a model of spondyloarthritis.

OBJECTIVES: Ankylosing spondylitis (AS) is a highly heritable immune-mediated arthropathy. Inflammation in AS is poorly understood. TBX21 encodes T-bet, a transcription factor, lying within a locus with genome-wide significant association with AS. T-bet is implicated in innate and adaptive immunity. However, the role of T-bet in AS pathogenesis is unclear. METHODS: We assessed the importance of T-bet in disease development and progression in peripheral blood mononuclear cells from 172 AS cases and 83 healthy controls carrying either risk or protective alleles of the peak AS-associated TBX21 single nucleotide polymorphism. Kinetics and localisation of T-bet expression in the SKG mouse model of spondyloarthropathy was examined, along with the impact of Tbx21 knockout on arthritis development in SKG mice. RESULTS: Patients with AS had higher T-bet expression than healthy individuals, driven predominantly by natural killer and CD8+ T cells, with expression levels in CD8+ T cells completely distinguishing AS cases from healthy controls. T-bet expression was increased in AS cases carrying risk compared with protective alleles of rs11657479. In curdlan-treated SKG mice, T-bet expression increased early after disease initiation and persisted throughout the course of disease. There was marked reduction in gut and peripheral joint inflammation, and less IFNγ-producing and IL-17-producing CD8+ T cells, in Tbx21-/- compared with wild-type SKG mice. CONCLUSIONS: AS-associated variants in TBX21 influence T-bet expression. T-bet+ innate and adaptive immune cells have altered IL-17 and IFNγ, and early activation marker CD69 expression than T-bet cells. This indicates that T-bet is a major component of inflammatory pathways of spondyloarthropathy in humans and mice.

ERAP2 functional knockout in humans does not alter surface heavy chains or HLA-B27, inflammatory cytokines or endoplasmic reticulum stress markers.

INTRODUCTION: Single nucleotide polymorphisms in ERAP2 are strongly associated with ankylosing spondylitis (AS). One AS-associated single nucleotide polymorphism, rs2248374, causes a truncated ERAP2 protein that is degraded by nonsense-mediated decay. Approximately 25% of the populations of European ancestry are therefore natural ERAP2 knockouts. We investigated the effect of this associated variant on HLA class I allele presentation, surface heavy chains, endoplasmic reticulum (ER) stress markers and cytokine gene transcription in AS. METHODS: Patients with AS and healthy controls with either AA or GG homozygous status for rs2248374 were studied. Antibodies to CD14, CD19-ECD, HLA-A-B-C, Valpha7.2, CD161, anti-HC10 and anti-HLA-B27 were used to analyse peripheral blood mononuclear cells. Expression levels of ER stress markers (GRP78 and CHOP) and proinflammatory genes (tumour necrosis factor (TNF), IL6, IL17 and IL22) were assessed by qPCR. RESULTS: There was no significant difference in HLA-class I allele presentation or major histocompatibility class I heavy chains or ER stress markers GRP78 and CHOP or proinflammatory gene expression between genotypes for rs2248374 either between cases, between cases and controls, and between controls. DISCUSSION: Large differences were not seen in HLA-B27 expression or cytokine levels between subjects with and without ERAP2 in AS cases and controls. This suggests that ERAP2 is more likely to influence AS risk through other mechanisms.