Cystic Fibrosis Screen Positive, Inconclusive Diagnosis (CFSPID): A new designation and management recommendations for infants with an inconclusive diagnosis following newborn screening.

BACKGROUND: Newborn screening (NBS) for cystic fibrosis (CF) results in the recognition of a number of infants with a positive NBS result, but an inconclusive diagnosis. Varied practice exists with respect to the management of these infants. METHODS: A Delphi consensus approach was used to determine agreement on statements generated by a core group of specialists. A designation (naming) exercise was required after Round 1 and further expert opinion was sought to guide that process. After Round 2, a sensitivity analysis was undertaken to assess the impact of attrition on subsequent agreement levels. RESULTS: Infants were divided into group A (normal sweat chloride and two CFTR mutations, at least one of which has unclear phenotypic consequences) and group B (intermediate sweat chloride and one or no CFTR mutations). 32 statements were produced for Round 1 and 24 achieved consensus. After Round 1, a designation exercise was undertaken and the term "CF Screen Positive, Inconclusive Diagnosis (CFSPID)" was suggested for Round 2. Agreement was achieved for this statement and for all other statements aside from the need for routine respiratory culture, on which there was divided opinion. The core group advocated local practice for this issue. A sensitivity analysis demonstrated that consensus for Round 2 was achieved by change in opinion rather than attrition. CONCLUSION: We have generated a new designation and statements to guide the management of infants with CFSPID through a robust international Delphi process. These statements will be a valuable tool for CF teams and will improve the consistency of management of these infants.

NIDCAP improves brain function and structure in preterm infants with severe intrauterine growth restriction.

OBJECTIVE: The effect of NIDCAP (Newborn Individualized Developmental Care and Assessment Program) was examined on the neurobehavioral, electrophysiological and neurostructural development of preterm infants with severe intrauterine growth restriction (IUGR). STUDY DESIGN: A total of 30 infants, 27-33 weeks gestation, were randomized to control (C; N=17) or NIDCAP/experimental (E; N=13) care. Baseline health and demographics were assessed at intake; electroencephalography (EEG) and magnetic resonance imaging (MRI) at 35 and 42 weeks postmenstrual age; and health, growth and neurobehavior at 42 weeks and 9 months corrected age (9 months). RESULTS: C and E infants were comparable in health and demographics at baseline. At follow-up, E infants were healthier, showed significantly improved brain development and better neurobehavior. Neurobehavior, EEG and MRI discriminated between C and E infants. Neurobehavior at 42 weeks correlated with EEG and MRI at 42 weeks and neurobehavior at 9 months. CONCLUSION: NIDCAP significantly improved IUGR preterm infants' neurobehavior, electrophysiology and brain structure. Longer-term outcome assessment and larger samples are recommended.

Is the Newborn Individualized Developmental Care and Assessment Program (NIDCAP) effective for preterm infants with intrauterine growth restriction?

OBJECTIVE: This study investigates the effectiveness of the Newborn Individualized Developmental Care and Assessment Program (NIDCAP) on neurobehavioral and electrophysiological functioning of preterm infants with severe intrauterine growth restriction (IUGR). STUDY DESIGN: Thirty IUGR infants, 28 to 33 weeks gestational age, randomized to standard care (control/C=18), or NIDCAP (experimental/E=12), were assessed at 2 weeks corrected age (2wCA) and 9 months corrected age (9mCA) in regard to health, anthropometrics, and neurobehavior, and additionally at 2wCA in regard to electrophysiology (EEG). RESULT: The two groups were comparable in health and anthropometrics at 2wCA and 9mCA. The E-group at 2wCA showed significantly better autonomic, motor, and self-regulation functioning, improved motility, intensity and response thresholds, and reduced EEG connectivity among several adjacent brain regions. At 9mCA, the E-group showed significantly better mental performance. CONCLUSION: This is the first study to show NIDCAP effectiveness for IUGR preterm infants.

Individualized developmental care for a large sample of very preterm infants: health, neurobehaviour and neurophysiology.

AIM: To assess medical and neurodevelopmental effects of Newborn Individualized Developmental Care and Assessment Program (NIDCAP) for a large sample of very early-born infants. METHODS: One hundred and seven singleton inborn preterm infants, <29 weeks gestational age (GA), <1250 g birth weight, enrolled in three consecutive phases, were randomized within phase to NIDCAP (treatment, E) or standard care (C). Treatment extended from admission to the Newborn Intensive Care Unit to 2 weeks corrected age (wCA). Outcome included medical, neurobehavioural and neurophysiological status at 2 wCA, and growth and neurobehavioural status at 9 months (m) CA. RESULTS: The C- and E-group within each of the three consecutive phases and across the three phases were comparable in terms of all background measures; they therefore were treated as one sample. The results indicated for the E-group significant reduction in major medical morbidities of prematurity as well as significantly improved neurodevelopmental (behaviour and electrophysiology) functioning at 2 wCA; significantly better neurobehavioural functioning was also found at 9 mCA. CONCLUSION: The NIDCAP is an effective treatment for very early-born infants. It reduces health morbidities and enhances neurodevelopment, functional competence and life quality for preterm infants at 2 w and 9 mCA.

Economic evaluation of recombinant human copper zinc superoxide dismutase administered at birth to premature infants.

OBJECTIVE: To determine the cost-effectiveness of recombinant human superoxide dismutase (rhSOD) in the prevention of chronic respiratory morbidity, defined as use of respiratory medications, in preterm infants. STUDY DESIGN: This retrospective economic evaluation was undertaken using data from a previously published randomized controlled trial of the use of rhSOD in neonates of birthweight 600 to 1200 g. This ancillary study measured all relevant direct medical costs from birth to 1 year corrected age using resource data collected for infants from the clinical trial. Unit costs were derived from secondary datasets in similar populations, stratified by level of care or diagnosis. All costs were expressed in 2003 US dollars. RESULT: rhSOD was associated with a highly favorable incremental cost of only $378 per chronic respiratory morbidity averted at 1 year corrected age. There was a 95% probability that the therapy would be considered cost-effective if a decision maker was willing to pay $7000 to avert one infant with long-term significant respiratory illness, and a 52% probability that it would actually reduce costs while improving outcomes. These results were more pronounced among infants <27 weeks gestational age at birth. CONCLUSION: Based on resource data from a single randomized trial, this retrospective analysis supports the potential economic desirability of rhSOD treatment in this population.

Genetic counseling after implementation of statewide cystic fibrosis newborn screening: Two years' experience in one medical center.

PURPOSE: To study the follow-up of genetic counseling performed in families with a newborn detected with one cystic fibrosis (CF) mutation in a statewide newborn screening pilot program. METHODS: Newborns in Massachusetts with an elevated trypsinogen level on newborn screen who are found to have one mutation for CF on a selected mutation assay undergo sweat testing for CF, and their families receive genetic counseling. The genetic counseling focuses on carrier risk for the parents of the newborn and offers carrier testing. We studied the yield of genetic counseling and the resulting genetic testing performed on the families of infants found to be CF carriers who underwent sweat testing in a single institution. RESULTS: Of 102 newborns evaluated with a single CF mutation, 2 (twins) had sweat test results consistent with CF. A total of 101 families were counseled, and 95 were offered DNA-based CF carrier testing. Eighty-two percent of all parents chose to have CF carrier testing, and in five couples, both members were carriers. One of these couples (whose newborn was only a carrier) had an older child who was unexpectedly found to have CF. CONCLUSIONS: Sweat testing of newborns at increased risk for CF in conjunction with genetic counseling for their parents allows identification of infants with CF, finds couples at high risk for having a child with CF, identifies previously undiagnosed siblings with CF, and allows for potential identification of CF carriers in the extended family.

Antenatal glucocorticoid treatment does not reduce chronic lung disease among surviving preterm infants.

BACKGROUND: Antenatal glucocorticoid treatment (AGT) is associated with a number of postnatal benefits to the preterm infant, including reduced risk of respiratory distress syndrome, patent ductus arteriosus, intraventricular hemorrhage, and necrotizing enterocolitis. OBJECTIVE: To evaluate the hypothesis that maternal AGT not only reduces the risk of surfactant deficiency but also reduces the occurrence of chronic lung disease (CLD) among surviving preterm infants. STUDY DESIGN: Case-referent study of 1454 very low birth weight infants born between January 1991 and December 1993 at 4 university medical centers. RESULTS: Rates of AGT varied among the 4 centers (11%-69%), as did rates of CLD (4%-21%), defined as a requirement for supplemental oxygen at 36 weeks' postmenstrual age. CLD rates at each center, however, did not vary with the rate of AGT exposure. In multivariate logistic regression analyses, AGT did not contribute significantly to CLD risk. CONCLUSION: AGT may play a less prominent role in modifying CLD risk than other factors such as biologic immaturity, infection, or neonatal intensive care unit practices, such as mechanical ventilation, continuous positive airway pressure, and surfactant replacement therapy.

Long-term follow-up of premature infants treated with prophylactic, intratracheal recombinant human CuZn superoxide dismutase.

OBJECTIVE: To examine the long-term effects of treatment with recombinant human CuZn superoxide dismutase (rhSOD) in infants enrolled previously in two placebo-controlled trials. STUDY DESIGN: Records for 46 (88%) infants were examined, with 19 infants having received either single or multiple intratracheal (i.t.) doses of placebo, 12 having received a single i.t. dose of rhSOD, and 15 having received multiple i.t. doses of rhSOD. Mean age at follow-up was 28 months corrected age. Records were examined for neurologic dysfunction, developmental delay, and any significant medical disorders. RESULTS: Four placebo infants (21%) had evidence of neurodevelopmental abnormalities and four infants developed asthma. Four single-dose rhSOD infants (33%) had neurodevelopmental abnormalities and two infants developed asthma. One multiple-dose rhSOD infant had evidence of neurodevelopmental abnormalities and one developed asthma. No other differences were found between the placebo and rhSOD groups. CONCLUSION: Preliminary data suggest that rhSOD is safe and not associated with any long-term adverse effects. Further results will depend on the results of multicenter trials of rhSOD in preterm infants.

Do clinical markers of barotrauma and oxygen toxicity explain interhospital variation in rates of chronic lung disease? The Neonatology Committee for the Developmental Network.

OBJECTIVE: To explore the hypothesis that variation in respiratory management among newborn intensive care units (NICUs) explains differences in chronic lung disease (CLD) rates. DESIGN: Case-cohort study. SETTING: NICUs at 1 medical center in New York (Babies' and Children's Hospital [Babies']) and 2 in Boston (Beth Israel Hospital and Brigham and Women's Hospital [Boston]). STUDY POPULATION: Four hundred fifty-two infants born at 500 to 1500 g birth weight between January 1991 and December 1993, who were enrolled in an epidemiologic study of neonatal intracranial white matter disorders. CASE DEFINITION: Supplemental oxygen required at 36 weeks' postmenstrual age. RESULTS: The prevalence rates of CLD differed substantially between the centers: 4% at Babies' and 22% at the 2 Boston hospitals, despite similar mortality rates. Initial respiratory management at Boston was more likely than at Babies' to include mechanical ventilation (75% vs 29%) and surfactant treatment (45% vs 10%). Case and control infants at Babies' were more likely than were those at Boston to have higher partial pressure of carbon dioxide and lower pH values on arterial blood gases. However, measures of oxygenation and ventilator settings among case and control infants were similar at the 2 medical centers in time-oriented logistic regression analyses. In multivariate logistic regression analyses, the initiation of mechanical ventilation was associated with increased risk of CLD: after adjusting for other potential confounding factors, the odds ratios for mechanical ventilation were 13.4 on day of birth, 9.6 on days 1 to 3, and 6.3 on days 4 to 7. Among ventilated infants, CLD risk was elevated for maximum peak inspiratory pressure >25 and maximum fraction of inspired oxygen = 1.0 on the day of birth, lowest peak inspiratory pressure >20 and maximum partial pressure of carbon dioxide >50 on days 1 to 3, and lowest white blood count <8 K on days 4 to 7. Even after adjusting for white blood count <8 K and the 4 respiratory care variables, infants in Boston continued to be at increased risk of CLD, compared with premature infants at Babies' Hospital. CONCLUSION: In multivariate analyses, a number of specific measures of respiratory care practice during the first postnatal week were associated with the risk of a very low birth weight infant developing CLD. However, after adjusting for baseline risk, most of the increased risk of CLD among very low birth weight infants hospitalized at 2 Boston NICUs, compared with those at Babies' Hospital, was explained simply by the initiation of mechanical ventilation.

Pulmonary outcome in cystic fibrosis is influenced primarily by mucoid Pseudomonas aeruginosa infection and immune status and only modestly by genotype.

Whether allelic variants of the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) independently contribute to pulmonary outcome in CF patients has not been resolved. We used both cross-sectional and mixed-model longitudinal analyses of data from CF patients that were at least 12 years old to determine the influence on pulmonary function (percent predicted forced expiratory volume [FEV(1)]) of the CFTR gene genotype, gender, mucoid Pseudomonas aeruginosa (MPA) infection status, presence of total opsonic antibody to MPA, and, separately, the opsonic antibody activity specific to the mucoid exopolysaccharide (MEP) surface antigen. Two different factors were independently associated with the lack of MPA infection: a high level of MEP-specific opsonic activity (MSOA), implicating an immunologically based mechanism of resistance to infection, and a lack of any type of opsonic antibody to MPA, indicative of no significant exposure or infection. This latter phenotype was found in a subset of CF patients who carried at least one uncommon CFTR gene allele suggestive of a genetic basis for resistance to infection in this group of older CF patients. For CF patients in whom both CFTR gene alleles were identified by screening for the 12 most common variants (75% of alleles), cross-sectional analysis showed that MPA infection was best correlated with lower percent predicted FEV(1), while genotype (two versus one DeltaF508 CFTR gene allele) and a low level of MSOA were associated with increased risk of infection. A mixed-model analysis of longitudinal spirometric measurements that considered multiple risk factors to derive regression equations was used to determine which clinical parameters had the greatest effect on the annual rate of decline in percent predicted FEV(1). This analysis showed that the CFTR gene genotype only modestly modified the constant (y intercept) of the derived equations, while gender and MPA infection status had the largest effects on annual rates of decline in percent predicted FEV(1). These results indicate that the CFTR genotype is usually not a primary determinant of pulmonary function in most CF patients, but gender and MPA infection status are. Infection status is potentially influenced by both immunologic (a high level of MSOA) and genetic factors, such as carriage of a CFTR gene allele that leads to a diagnosis of CF but still confers resistance to infection that is comparable to that of the wild-type CFTR gene.

Variable levels of normal RNA in different fetal organs carrying a cystic fibrosis transmembrane conductance regulator splicing mutation.

Disease severity varies among cystic fibrosis (CF) patients carrying the same cystic fibrosis transmembrane conductance regulator (CFTR) genotype and among organs of the same individual. It has been shown that the class V splicing mutation 3849 + 10 kb C--> T produces both normal and aberrantly spliced CFTR transcripts. We analyzed the levels of normal CFTR messenger RNA (mRNA) in different organs of an aborted fetus carrying the 3849 + 10 kb C--> T mutation, and found that they correlated with the histopathologic changes observed in these organs. We performed semiquantitative nondifferential reverse transcription-polymerase chain reaction on several organs from a 22-wk aborted CF fetus carrying the 3849 + 10 kb C--> T mutation. A very low level (1%) of normal CFTR mRNA was detected in the severely affected ileum of this fetus. Higher levels were found in the histopathologically unaffected trachea (17%), colon (19%), and lung (26%). Thus, as early as in utero, the regulation of alternative splice-site selection is an important mechanism underlying variable CF severity. Understanding of the mechanisms regulating alternative splicing in different tissues will contribute to potential therapy for patients carrying splicing mutations in CF and other human disease genes.

Buccal cell DNA mutation analysis for diagnosis of cystic fibrosis in newborns and infants inaccessible to sweat chloride measurement.

OBJECTIVES: To assess the application of DNA-based cystic fibrosis transmembrane conductance regulator (CFTR) gene mutation analysis as a primary cystic fibrosis (CF) diagnostic test in preterm and term newborns and infants for whom the quantitative pilocarpine iontophoresis test (QPIT) cannot be used. DESIGN: Retrospective survey. SETTING: DNA Diagnostic Laboratory, Children's Hospital, Boston, Massachusetts. Buccal cell DNA samples were received from inpatients, outpatients, and three neonatal intensive care units. OUTCOME MEASURE: Detection of at least 1 of 12 CFTR mutations. PATIENTS: Between November 1, 1992, and April 30, 1994, 28 newborns and infants under 12 months of age at risk for CF had CFTR DNA mutation analysis performed because a sweat chloride (SC) value could not be obtained. QPIT was either not performed (infant weight <2 kg, QPIT not available at site of hospitalization, or infant not accessible to QPIT laboratory) or was inconclusive (sweat volume <75 mg or indeterminate SC [>/=40, <60 mEq/L]). The postnatal age at time of testing ranged from 1 day to 11 months, and gestational age at birth from 25 to 40 weeks. RESULTS: Six (21%) of 28 infants with unobtainable or indeterminate QPIT had 1 or 2 CFTR mutations detected. Immediate CF diagnosis by direct detection of 2 CFTR mutations was made in 5 of these 6 patients. Definitive CF diagnosis in the infant with 1 CFTR mutation was delayed until an elevation in SC could be documented. The patients with no CFTR mutations detected had a low likelihood of CF. CONCLUSIONS: For infants in whom CF is suspected but QPIT cannot be obtained, buccal cell DNA-based CFTR mutation analysis can be used as a rapid, noninvasive primary diagnostic test. This simple mode of DNA collection may aid in the diagnosis of other inherited disorders in newborns.

Heterogeneity of phenotype in two cystic fibrosis patients homozygous for the CFTR exon 11 mutation G551D.

In the heterozygous state, the cystic fibrosis transmembrane conductance regulator (CFTR) exon 11 mutation G551D has been described as "severe," causing pancreatic insufficiency. Two cystic fibrosis (CF) patients homozygous for this mutation showed a mild rather than severe pancreatic phenotype and a variable pulmonary phenotype.

Fetal lung masses: prenatal course and outcome.

We describe 25 cases of echogenic or complex fetal lung masses seen sonographically and suspected of being cystic adenomatoid malformations or sequestrations of the lung. On the basis of prenatal sonographic appearance, 40% of fetuses were suspected of having type 1, 20% type 2, and 40% type 3 cystic adenomatoid malformations or sequestrations. Sixteen (64%) of the 25 fetuses with lung masses survived the perinatal period, and 80% of the nonaborted fetuses survived. Eleven infants (69% of liveborns) had no respiratory symptoms at birth. Nine of the survivors underwent surgical resections of their masses after birth, whereas the other seven children are being followed conservatively. The postnatal diagnoses revealed that four of the fetuses had sequestrations, one had a sequestration with elements consistent with cystic adenomatoid malformation, and two who were thought to have type 1 cystic adenomatoid malformation had an esophageal duplication cyst and a thoracic neuroblastoma, respectively. All the other infants who had a pathologic diagnosis or postnatal imaging had cystic adenomatoid malformations. Increasing mediastinal shift was associated with decreasing survival as 90% of fetuses with no mediastinal shift are alive, whereas 50% of the nonaborted fetuses with a severe mediastinal shift survived. Follow-up scans in utero were available in 15 cases. The size of the mass became smaller in 53% during gestation. Seventy-one percent of pregnancies had normal amniotic fluid volumes and 29% were complicated by polyhydramnios. Survival of nonaborted fetuses was 100% in pregnancies with normal amniotic fluid compared with 50% in those with polyhydramnios. Eight percent of the fetuses with chest masses had additional structural abnormalities and were karyotypically abnormal. In conclusion, many fetuses with lung masses show improvement of the sonographic findings in utero, and many infants may not be symptomatic at birth. Of the survivors in this series, only slightly greater than half underwent surgery.

Second trimester prenatal findings in duodenal and esophageal atresia without tracheoesophageal fistula.

The combination of duodenal atresia and esophageal atresia without tracheoesophageal fistula leads to a closed loop of bowel involving the distal esophagus, stomach, and duodenum. Prenatally, this association of anomalies is visualized as a characteristic dilated C-shaped fluid collection in the fetal abdomen. We report three cases of the association of duodenal and esophageal atresia without tracheoesophageal fistula, identified sonographically in the second trimester of pregnancy.

Multiplex PCR amplification from the CFTR gene using DNA prepared from buccal brushes/swabs.

Traditionally, DNA used for PCR-based diagnostic analysis has originated from white cells fractionated from whole blood. Although this method yields substantial quantities of DNA, there are some drawbacks to the procedure, including the inconvenience of drawing blood, risk of exposure to blood-borne pathogens, liquid sample handling, and the somewhat involved extraction procedure. Alternatively, DNA for genetic diagnosis has been derived from finger stick blood samples, hair roots, cheek scrapings, and urine samples. Oral saline rinses have also been used extensively as a means of collecting buccal epithelial cells as a DNA source. However, this method still requires liquid sample handling. Herein, we present our results involving the rapid extraction of DNA from buccal cells collected on cytology brushes and swabs for use in PCR reactions, specifically the multiplex amplification of 5 exons within the CFTR gene. The quality of DNA isolated from buccal cells, collected in this manner, has been sufficient to reproducibly support multiplex amplification. Cheek cell samples and the DNA prepared from them as described here are highly stable. The success rate of PCR amplification on DNA prepared from buccal cells is 99%. In a blind study comparing the analysis of 12 mutations responsible for cystic fibrosis in multiplex products amplified with DNA from both blood and buccal cell samples from 464 individuals, there was 100% correlation of results for blood and cheek cell DNA, validating the use of DNA extracted from cheek cells collected on cytology brushes for use in genetic testing.

C1 inhibitor hinge region mutations produce dysfunction by different mechanisms.

Heterozygosity for a mutant dysfunctional C1 inhibitor protein, a member of the serine proteinase inhibitor (serpin) superfamily, results in type II hereditary angioneurotic oedema. We identified a "hinge" region mutation in C1 inhibitor with a Val to Glu replacement at P14 Val-432. Recombinant C1 inhibitors P10 Ala-->Thr and P14Val-->Glu did not form stable complexes with fluid phase C1s or kallikrein. The P14 Val-->Glu mutant, however, was cleaved to a 96K form by C1s, while the P10 Ala-->Thr mutant was not. The recombinant P10 mutant also did not complex with C1s, kallikrein or beta-factor Xlla-Sepharose. The two mutations, therefore, result in dysfunction by different mechanisms: in one (P14 Val-->Glu), the inhibitor is converted to a substrate, while in the other (P10 Ala-->Thr), interaction with target protease is blocked.