Standards of care guidance for sweat testing; phase two of the ECFS quality improvement programme.

More than five decades after the introduction of the quantitative pilocarpine iontophoresis technique, surveys still highlight inconsistencies in the performance and reporting of sweat tests in Europe. The sweat test remains key for the Cystic Fibrosis (CF) diagnostic pathway for all age groups, as it reflects the basic pathophysiological defect in the sweat gland. It is also critical following newborn screening as a confirmatory diagnostic step. Despite its importance, sweat test quality is variable whether performed in the laboratory or as a point of care test. The ECFS DNWG aims to improve sweat test performance, taking into account the barriers and issues identified in the European survey; the previous step in the ECFS sweat test project. This manuscript proposes a grading of sweat test guidance from "acceptable" to "optimal", aiming to pragmatically improve quality while taking into account local situations, especially in resource-limited settings.

Real life practice of sweat testing in Europe.

Evidence based guidelines exist for sweat testing, which remains a key component of a diagnosis of cystic fibrosis (CF), especially following newborn bloodspot screening (NBS). There are emerging challenges with respect to maintaining a valid sweat test service, notably a smaller number of sweat tests ordered in regions with established NBS programmes where Pediatricians refer less children for sweat testing, younger patients and equipment becoming obsolete. The ECFS Diagnostic Network Working Group has undertaken a comprehensive survey to better define sweat test practice across Europe. The survey was completed by 136 European respondents representing a CF center or laboratory providing a sweat test service (65% from regions with NBS for CF). There was considerable variance in practice, often not consistent with guidelines. In particular collection of sweat from two sites was rarely reported in European centres in contrast to US guidelines. There was a range of different references quoted for cut-off for both a positive and intermediate test. Most responses suggest cost is becoming an increasing issue and is not sufficiently reimbursed. This work will inform best practice guidelines and resources to sustain and improve sweat testing in Europe.

A randomized placebo-controlled study on high-dose oral algal docosahexaenoic acid supplementation in children with cystic fibrosis.

Low plasma concentrations of docosahexaenoic acid (DHA) are reported in unsupplemented cystic fibrosis (CF) patients. Forty-one CF patients aged from 6 to 12 years were randomized to receive high-dose DHA (100 mg/kg/day in the first month and 1g per day thereafter through a 12-month supplementation) or placebo (germ oil). Primary outcome was percentage change in plasma AA:DHA ratio. Secondary outcomes were changes in the number of pulmonary exacerbations compared to previous year, lung function, BMI, skinfold thicknesses, and body composition assessed by DXA and in serum concentrations of C-reactive protein, cytokines and vitamin (α-tocopherol and retinol). Compared to the control group plasma AA:DHA ratio decreased in the intervention group after 6 months (median percentage changes: -73% in the intervention group vs. -10% in the control group, P=0.001). No differences were detected between groups for secondary outcomes. Despite a decrease of the AA/DHA ratio, DHA supplementation for one year did not induce any significant biochemical and clinical improvement in CF patients.