Research Information System
47th ECFS Conference,, Glasgow, England, 5 - 08 June 2024, pp.66-67, (Full Text)
Introduction: With the detection of high serum immune reactive trypsinogen (IRT) levels in cystic fibrosis (CF), IRT has become the centre of newborn screening (NBS) protocols. We aimed to evaluate the relationship between IRT levels and sweat chloride levels, CFTR mutations, and pancreatic functions in CF patients. Methods: CF patients registered into the National Cystic Fibrosis Registry (in partnership with the European Cystic Fibrosis Patient Registry) were included in this study. IRT levels were obtained from the NBS data system of the Ministry of Health. Patients’ IRT levels, sweat chloride levels, presence of F508del mutation, and pancreatic functions were compared statistically. Results: A total of 579 patients were included in the study. The median age at diagnosis and IRT level were three (0–72) months and 131.3 (1.7–479.0), respectively. F508del mutation was present in at least one allele in 160 (30.5%) of 525 (90.7%) who underwent genetic diagnostic testing. High chloride levels were detected in 270 (77.8%) of 347 (59.9%) patients who underwent sweat testing. Pancreatic insufficiency (PI) and meconium ileus (MI) were present in 476 (82.5%) and 36 (6.3%) patients, respectively. The relationship between IRT levels, newborn screening status and other variables is presented in Table 1 and 2. A positive and moderate correlation was found between the quantitative IRT and sweat chloride levels (r: 0.470, p < 0.001). Table 1. Comparison of patients’ NBS status with sweat test results, genetic mutations, and exocrine pancreatic function status. NBS positive n (%) NBS negative n (%) Total n (%) p value Sweat Chloride Test Negative Intermediate Positive 15 (68.2) 38 (69.1) 243 (90.0) 7 (31.8) 17 (30.9) 27 (10.0) 22 (100) 55 (100) 270 (100) <0.001a Presence of F508del Mutation Yes No 146 (91.3) 289 (85.0) 14 (8.8) 51 (15.0) 160 (100) 340 (100) 0.053a Type of F508del Mutation Heterozygote Homozygote 77 (87.5) 59 (96.7) 11 (12.5) 2 (3.3) 88 (100) 61 (100) 0.050a Presence of Pancreas Insufficiency Yes No 418 (87.8) 77 (76.2) 58 (12.2) 24 (23.8) 476 (100) 101 (100) 0.002a Presence of Meconium Ileus Yes No 33 (91.7) 453 (85.3) 3 (8.3) 78 (14.7) 36 (100) 531 (100) 0.292a a Chi-squared Test. Table 2. Comparison of patients’ IRT quantitative values and sweat test results, genetic mutations, and exocrine pancreatic function status. Median Minimum Maximum p value Sweat Chloride Test Negative Intermediate Positive 83.2 89.0 156.4 11.4 1.7 6.6 149.0 266.0 479.0 <0.001b Presence of F508del Mutation Yes No 158.2 123.1 6.6 11.4 479.0 419.0 <0.001a Type of F508del Mutation Heterozygote Homozygote 136.3 189.2 6.6 54.0 457.0 461.8 0.003a Presence of Pancreas Insufficiency Yes No 147.0 83.5 1.7 13.4 479.0 310.0 <0.001a Presence of Meconium Ileus Yes No 148.7 128.5 11.4 1.7 228.4 479.0 0.733a a Mann Whitney-U Test. b Kruskal Wallis Test. Conclusions: In CF patients, having high sweat chloride and IRT levels may be a risk factor for the development of PI. Unlike the literature, there was no difference in IRT levels between MI status.