Department of Development and Regeneration, Woman and Child Unit, CF Research Lab, KU Leuven, Leuven, Belgium.
Department of Pediatrics, Pediatric Pulmonology, University Hospitals Leuven, Leuven, Belgium.
Thorax. 2024 Aug 19;79(9):834-841. doi: 10.1136/thorax-2023-220964.
Diagnosing cystic fibrosis (CF) is not always straightforward, in particular when sweat chloride concentration (SCC) is intermediate and <2 CF-causing variants are identified. The physiological CFTR assays proposed in the guidelines, nasal potential difference and intestinal current measurement, are not readily available nor feasible at all ages. Rectal organoid morphology analysis (ROMA) was previously shown to discriminate between organoids from subjects with and without CF based on a distinct phenotypical difference: compared with non-CF organoids, CF organoids have an irregular shape and lack a visible lumen. The current study serves to further explore the role of ROMA when a CF diagnosis is inconclusive.
Organoid morphology was analysed using the previously established ROMA protocol. Two indices were calculated: the circularity index to quantify the roundness of organoids and the intensity ratio as a measure of the presence of a central lumen.
Rectal organoids from 116 subjects were cultured and analysed together with the 189 subjects from the previous study. ROMA almost completely discriminated between CF and non-CF. ROMA indices correlated with SCC, pancreatic status and genetics, demonstrating convergent validity. For cases with an inconclusive diagnosis according to current guidelines, ROMA provided additional diagnostic information, with a diagnostic ROMA classification for 18 of 24 (75%).
ROMA provides additional information to support a CF diagnosis when SCC and genetics are insufficient for diagnostic classification. ROMA is standardised and can be centralised, allowing future inclusion in the diagnostic work-up as first-choice physiological assay in case of an unclear diagnosis.
诊断囊性纤维化 (CF) 并不总是那么简单，尤其是当汗液氯化物浓度 (SCC) 处于中间值且未发现 <2 种致 CF 变异体时。指南中提出的生理 CFTR 检测方法，如鼻电位差和肠道电流测量，不仅不易获得，而且在所有年龄段都不可行。直肠类器官形态分析 (ROMA) 先前已被证明可以根据明显的表型差异来区分 CF 患者和非 CF 患者的类器官：与非 CF 类器官相比，CF 类器官形状不规则，缺乏可见的腔。本研究旨在进一步探索当 CF 诊断不确定时 ROMA 的作用。
使用先前建立的 ROMA 方案分析类器官形态。计算了两个指数：圆度指数，用于量化类器官的圆度；强度比，用于衡量中央腔的存在。
培养了 116 名受试者的直肠类器官，并与之前研究的 189 名受试者进行了分析。ROMA 几乎可以完全区分 CF 和非 CF。ROMA 指数与 SCC、胰腺状态和遗传学相关，具有收敛效度。对于根据现行指南诊断不确定的病例，ROMA 提供了额外的诊断信息，其中 24 例中的 18 例（75%）具有诊断 ROMA 分类。
当 SCC 和遗传学不足以进行诊断分类时，ROMA 可提供额外信息以支持 CF 诊断。ROMA 标准化且可集中化，可作为首选生理检测方法纳入未来的诊断工作流程，以解决诊断不明确的问题。
