A reference human induced pluripotent stem cell line for large-scale collaborative studies

Human induced pluripotent stem cell (iPSC) lines are a powerful tool for studying development and disease, but the considerable phenotypic variation between lines makes it challenging to replicate key findings and integrate data across research groups. To address this issue, we sub-cloned candidate human iPSC lines and deeply characterized their genetic properties using whole genome sequencing, their genomic stability upon CRISPR-Cas9-based gene editing, and their phenotypic properties including differentiation to commonly used cell types. These studies identified KOLF2.1J as an all-around well-performing iPSC line. We then shared KOLF2.1J with groups around the world who tested its performance in head-to-head comparisons with their own preferred iPSC lines across a diverse range of differentiation protocols and functional assays. On the strength of these findings, we have made KOLF2.1J and its gene-edited derivative clones readily accessible to promote the standardization required for large-scale collaborative science in the stem cell field

Clinical response to gluten withdrawal is not an indicator of coeliac disease.

OBJECTIVE: Although the diagnosis of coeliac disease requires specific histological and serological findings, patients considered to be affected by coeliac disese only on the basis of clinical improvement after gluten withdrawal are commonly referred to our outpatient clinic. The objective of this study was to investigate whether the clinical response of gastrointestinal symptoms to gluten withdrawal and subsequent dietray re-introduction could be an indicator of the presence of coeliac disease. MATERIAL AND METHODS: Form December 1998 to January 2007, 180 patients on a gluten-free diet because of a diagnosis of coeliac disease not based on proper diagnostic criteria came to our out-patient clinic. In 112 of these patients, gluten was re-introduced into their diet. Subsequent duodenal biopsies and endomysial antibodies confirmed the diagnosis of coelliac disease in 51 of them. The relationship between improvement/worsening of symptoms and withdrawal/re-introduction of dietary gluten was analysed. RESULTS: Gastrointestinal symptoms improved in 64.7% of coeliac patients and 75.0% of non-coeliac patients after gluten withdrawal (chi(2) test, p=NS). Gluten re-introduction was followed by clinical exacerbation in 71.4% of coeliac patients and 54.2% of non-coeliac patients (chi(2) test, p =NS): The positive predictive value for clinical improvement after gluten withdrawal was 36%; the positive predictive value for clinical exacerbation after gluten re-introduction was 28%. CONCLUSIONS: Clinical response to either withdrawal or re-introduction of dietary gluten has no role in the diagnosis of coeliac disease