Progressive malnutrition, severe anemia, hepatic dysfunction, and respiratory failure in a three-month-old white girl

Severe lung disease in children with cystic fibrosis missed in newborn screening

BACKGROUND

Cystic fibrosis (CF) is now routinely diagnosed through newborn screening (NBS), but the tests employed in the USA have been evolving for two decades as missed cases become recognized and lab methods improve in association with more knowledge about CF genetics. New Jersey was among the first states to implement CF NBS in 2001 when it introduced the original two-tiered method that combined measurements of immunoreactive trypsinogen (IRT) with detection of the principal pathogenic variant (F508del) in the cystic fibrosis transmembrane conductance regulator (CFTR) gene.

OBJECTIVE

With continuation of the IRT/DNA (F508del) algorithm for two decades and identification of screening false negative children, we decided to examine the condition of some missed cases with special attention to their respiratory status.

METHODS

To strengthen the arguments for quality improvement in New Jersey's CF NBS program, we reviewed and evaluated false negative cases to determine the potential extent of preventable patient suffering as a consequence of delayed diagnoses.

RESULTS

Five children with CF who had false negative screening results were studied in detail. In each case there was a different cause of the negative screening results. They all had clinically significant/severe lung disease, ranging from chronic cough with CF pathogens on respiratory culture at a young age to respiratory failure.

CONCLUSION

This case series highlights the consequences of false negative screening results, which served as the impetus to upgrade New Jersey's CF NBS algorithm. Implemented changes include lowering the IRT cutoff to 70 ng/mL and expanding to a 139 variant CFTR panel. In 2023, a floating IRT cutoff is anticipated to be implemented.

Newborn Screening for Cystic Fibrosis: A Qualitative Study of Successes and Challenges from Universal Screening in the United States

Cystic fibrosis (CF) newborn screening (NBS) was universally adopted in 2009 in the United States. Variations in NBS practices between states may impact the timing of diagnosis and intervention. Quantitative metrics can provide insight into NBS programs (NBSP), but the nuances cannot be elucidated without additional feedback from programs. This study was designed to determine facilitators and barriers to timely diagnosis and intervention following NBS for CF. The median age at the first CF event for infants with CF within each state was used to define early and late states (n = 15 per group); multiple CF centers were invited in states with more than two CF centers. Thirty states were eligible, and 61 NBSP and CF centers were invited to participate in structured interviews to determine facilitators and barriers. Once saturation of themes was reached, no other interviews were conducted. Forty-five interviews were conducted (n = 16 early CF center, n = 12 late CF center, n = 11 early NBSP, and n = 6 late NBSP). Most interviewees reported good communication between CF centers and NBSP. Communication between primary care providers (PCPs) and families was identified as a challenge, leading to delays in referral and subsequent diagnosis. The misperception of low clinical risk in infants from racial and ethnic minority groups was a barrier to early diagnostic evaluation for all groups. NBSP and CF centers have strong relationships. Early diagnosis may be facilitated through more engagement with PCPs. Quality improvement initiatives should focus on continuing strong partnerships between CF centers and NBS programs, improving education, communication strategies, and partnerships with PCPs, and improving CF NBS timeliness and accuracy.

The Impact of the CFTR Gene Discovery on Cystic Fibrosis Diagnosis, Counseling, and Preventive Therapy

Discovery of the cystic fibrosis transmembrane conductance regulator (CFTR) gene was the long-awaited scientific advance that dramatically improved the diagnosis and treatment of cystic fibrosis (CF). The combination of a first-tier biomarker, immunoreactive trypsinogen (IRT), and, if high, DNA analysis for CF-causing variants, has enabled regions where CF is prevalent to screen neonates and achieve diagnoses within 1-2 weeks of birth when most patients are asymptomatic. In addition, IRT/DNA (CFTR) screening protocols simultaneously contribute important genetic data to determine genotype, prognosticate, and plan preventive therapies such as CFTR modulator selection. As the genomics era proceeds with affordable biotechnologies, the potential added value of whole genome sequencing will probably enhance personalized, precision care that can begin during infancy. Issues remain, however, about the optimal size of CFTR panels in genetically diverse regions and how best to deal with incidental findings. Because prospects for a primary DNA screening test are on the horizon, the debate about detecting heterozygote carriers will likely intensify, especially as we learn more about this relatively common genotype. Perhaps, at that time, concerns about CF heterozygote carrier detection will subside, and it will become recognized as beneficial. We share new perspectives on that issue in this article.

Cystic fibrosis presenting with haematological abnormalities

Although cystic fibrosis (CF) is common, the diagnosis (and subsequent treatment) may be delayed if the presentation is atypical. We present three cases of children with CF who presented with haematological abnormalities. In all cases, they underwent extensive and invasive investigations prior to the diagnosis.

Cystic fibrosis-associated liver disease: a population-based study

OBJECTIVES

The aim of this study was to explore the clinical factors associated with the development of cystic fibrosis-associated liver disease (CFALD).

STUDY DESIGN

This was a case-control study of all children (age 5-18 years) with established CFALD in the Republic of Ireland between January 1999 and June 2000. Each child was pair matched for age and sex with a patient with cystic fibrosis (CF) without evidence of liver disease. Only children with clinically overt liver disease were enrolled in the disease group.

RESULTS

Patients with established CFALD (n = 42; 26 boys) were enrolled. Children with CFALD had worse forced expiratory volume in 1 second values than those without CFALD. However, chest radiography and clinical scores did not differ between groups. Height (mean difference, -4.2 cm [95% confidence interval [CI], -7.41 to -0.90], P =.014), weight (mean difference, -3.21 kg [95% CI, -6.03 to -0.40], P =.026), and mid-upper arm circumference (mean difference, -1.23 cm [95% CI, -2.35 to -0.12], P =.031) were significantly lower among children with CFALD. Children with CFALD were given diagnoses of CF later than children without liver disease. There were more children with meconium ileus in the control group (14 vs 4) than among those with CFALD.

CONCLUSIONS

Children with established CFALD have impaired growth and nutrition, altered body composition, and worse forced expiratory volume in 1 second values. CFALD is associated with later age of diagnosis of CF.

Early diagnosis of cystic fibrosis through neonatal screening prevents severe malnutrition and improves long-term growth. Wisconsin Cystic Fibrosis Neonatal Screening Study Group

OBJECTIVE

Despite its relative frequency among autosomal recessive diseases and the availability of the sweat test, cystic fibrosis (CF) has been difficult to diagnose in early childhood, and delays can lead to severe malnutrition, lung disease, or even death. The Wisconsin CF Neonatal Screening Project was designed as a randomized clinical trial to assess the benefits and risks of early diagnosis through screening. In addition, the incidence of CF was determined, and the validity of our randomization method assessed by comparing 16 demographic variables.

METHODOLOGY

Immunoreactive trypsinogen analysis was applied to dried newborn blood specimens for recognition of CF risk from 1985 to 1991 and was coupled to DNA-based detection of the DeltaF508 mutation from 1991 to 1994. Randomization of 650 341 newborns occurred when their blood specimens reached the Wisconsin screening laboratory. This created 2 groups-an early diagnosis, screened cohort and a standard diagnosis or control group. To avoid selection bias, we devised a unique unblinding method with a surveillance program to completely identify the control subjects. Because sequential analysis of nutritional outcome measures revealed significantly better growth in screened patients during 1996, we accelerated the unblinding and completely identified the control group by April 1998. Having each member of this cohort enrolled and evaluated for at least 1 year and having completed a comprehensive surveillance program, we performed another statistical analysis of anthropometric evaluated indices that includes all CF patients without meconium ileus.

RESULTS

The incidence of classical CF, ie, patients diagnosed in this trial with a sweat chloride of 60 mEq/L greater, was 1:4189. By incorporating other CF patients born during the randomization period, including 2 autopsy diagnosed patients and 8 probable patients, we calculate a maximum incidence of 1:3938 (95% confidence interval: 3402-4611). Although there were group differences in the proportion of patients with DeltaF508 genotypes and with pancreatic insufficiency, validity of the randomization plan was demonstrated by analyzing 16 demographic variables and finding no significant difference after adjustment for multiple comparisons. Focusing on patients without meconium ileus, we found a marked difference in the mean +/- standard deviation age of diagnosis for screened patients (13 +/- 37 weeks), compared with the standard diagnosis group (100 +/- 117). Anthropometric indices of nutritional status were significantly higher at diagnosis in the screened group, including length/height, weight, and head circumference. During 13 years of study, despite similar nutritional therapy and the inherently better pancreatic status of the control group, analysis of nutritional outcomes revealed significantly greater growth associated with early diagnosis. Most impressively, the screened group had a much lower proportion of patients with weight and height data below the 10th percentile throughout childhood.

CONCLUSIONS

Although the screened group had a higher proportion of patients with pancreatic insufficiency, their growth indices were significantly better than those of the control group during the 13-year follow-up evaluation and, therefore, this randomized clinical trial of early CF diagnosis must be interpreted as unequivocally positive. Our conclusions did not change when the height and weight data before 4 years of age for the controls detected by unblinding were included in the analysis. Also, comparison of growth outcomes after 4 years of age in all subjects showed persistence of the significant differences. Therefore, selection bias has been eliminated as a potential explanation. In addition, the results show that severe malnutrition persists after delayed diagnosis of CF and that catch-up may not be possible. We conclude that early diagnosis of CF through neonatal screening combined with aggressive nutritional therapy can result

Nutritional benefits of neonatal screening for cystic fibrosis. Wisconsin Cystic Fibrosis Neonatal Screening Study Group

BACKGROUND

Many patients with cystic fibrosis are malnourished at the time of diagnosis. Whether newborn screening and early treatment may prevent the development of a nutritional deficiency is not known.

METHODS

We compared the nutritional status of patients with cystic fibrosis identified by neonatal screening or by standard diagnostic methods. A total of 650,341 newborn infants were screened by measuring immunoreactive trypsinogen on dried blood spots (from April 1985 through June 1991) or by combining the trypsinogen test with DNA analysis (from July 1991 through June 1994). Of 325,171 infants assigned to an early-diagnosis group, cystic fibrosis was diagnosed in 74 infants, including 5 with negative screening tests. Excluding infants with meconium ileus, we evaluated nutritional status for up to 10 years by anthropometric and biochemical methods in 56 of the infants who received an early diagnosis and in 40 of the infants in whom the diagnosis was made by standard methods (the control group). Pancreatic insufficiency was managed with nutritional interventions that included high-calorie diets, pancreatic-enzyme therapy, and fat-soluble vitamin supplements.

RESULTS

The diagnosis of cystic fibrosis was confirmed by a positive sweat test at a younger age in the early-diagnosis group than in the control group (mean age, 12 vs. 72 weeks). At the time of diagnosis, the early-diagnosis group had significantly higher height and weight percentiles and a higher head-circumference percentile (52nd, vs. 32nd in the control group; P=0.003). The early-diagnosis group also had significantly higher anthropometric indexes during the follow-up period, especially the children with pancreatic insufficiency and those who were homozygous for the deltaF508 mutation.

CONCLUSIONS

Neonatal screening provides the opportunity to prevent malnutrition in infants with cystic fibrosis.

Severe hemolytic anemia associated with vitamin E deficiency in infants with cystic fibrosis. Implications for neonatal screening

Three infants are described with cystic fibrosis (CF) and malnutrition leading to severe anemia beginning as early as 6 weeks of age. Laboratory studies demonstrated high reticulocyte counts, negative Coombs' tests, abnormal peroxide hemolysis test results, and biochemical evidence of vitamin E deficiency. Oral administration of alpha-tocopherol resulted in rapid correction of the in vitro hemolysis and improvement of in vivo hematologic indices. Investigation of these patients supports the conclusion that the hemolytic anemia of infancy in CF is caused by vitamin E deficiency and should be treated promptly with 50 IU/day of vitamin E. Because two of the three patients were identified in a CF screening/surveillance program, we can estimate that the frequency of clinically significant anemia in CF infants is 4%. Our observations demonstrate a potential advantage of CF neonatal screening for individual patients susceptible to vitamin E-deficient hemolytic anemia and suggest that confirmatory follow-up diagnostic studies, such as sweat tests, should be performed by 4 to 6 weeks of age.