Early severe anemia as the first sign of cystic fibrosis

Severe anemia is reported to occur rarely in patients with cystic fibrosis (CF). This study aimed to determine the factors associated with early severe anemia in infants with CF. This study included 231 infants with CF from 3 pediatric CF centers ten year period that were retrospectively reviewed in terms of severe anemia as the first sign of CF. Factors that could affect anemia, such as age, pancreatic insufficiency, mutations, vitamin A and E, and albumin level were evaluated. Clinical and laboratory findings in CF patients that presented with severe anemia and no respiratory symptoms were compared to those in CF patients that did not present with severe anemia. Severe anemia as the first sign of CF was noted in 17 of 231 patients. Patient age, prolonged PT/INR and the albumin level differed significantly between the 2 groups of patients (P < 0.001). Feeding pattern, pancreatic insufficiency, vitamin E and A levels, and the types of genetic mutations did not differ between the 2 groups. The mean hemoglobin level was 5.59 +/- 0.21 g/dL and respiratory symptoms began a mean 6.3 months after diagnosis of CF in the anemia group

Evaluation of specificity and sensitivity of IRT/IRT protocol in the cystic fibrosis newborn screening program: 6-year experience of three tertiary centers

We aimed to evaluate cutoff values of immunoreactive trypsinogen (IRT)/IRT and determine relationship between IRT values and clinical characteristics of children with cystic fibrosis (CF). This study is cross-sectional study. Data of children with positive newborn screening (NBS) between 2015 and 2021 were evaluated in three pediatric pulmonology centers. Age at admission, sex, gestational age, presence of history of meconium ileus, parental consanguinity, sibling with CF, and doll-like face appearance, first and second IRT values, sweat chloride test, fecal elastase, fecal fat, biochemistry results, and age at CF diagnosis were recorded. Sensitivity and specificity of IRT cutoff values were evaluated. Of 815 children with positive NBS, 58 (7.1%) children were diagnosed with CF. Median values of first and second IRT were 157.2 (103.7–247.6) and 113.0 (84.0–201.5) μg/L. IRT values used in current protocol, sensitivity was determined as 96.6%, specificity as 17.2% for first IRT, and 96.6% sensitivity, 20.5% specificity for second IRT. Positive predictive value (PPV) was determined as 7.1%. When cutoff value for first IRT was estimated as 116.7 μg/L, sensitivity was 69.0% and specificity was 69.6%, and when cutoff value was set to 88.7 μg/L for second IRT, sensitivity was 69.0% and specificity was 69.0%. Area under curve was 0.757 for first and 0.763 for second IRT (p < 0.001, p < 0.001, respectively). PPV was calculated as 4.3%. Conclusion: Although sensitivity of CF NBS is high in our country, its PPV is significantly lower than expected from CF NBS programs. False-positive NBS results could have been overcome by revising NBS strategy.What is Known:• Although immunoreactive trypsinogen elevation is a sensitive test used in cystic fibrosis newborn screening, its specificity is low.• In countries although different algorithms are used, all strategies begin with the measurement of immunoreactive trypsinogen in dried blood spots.What is New:• In our study, it was shown that use of the IRT/IRT protocol for cystic fibrosis newborn screening is not sufficient for the cut-off values determined by the high number of patients.• Newborn screening strategy should be reviewed to reduce false positive newborn screening results