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.

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.

Type I C1 inhibitor deficiency with a small messenger RNA resulting from deletion of one exon.

The molecular genetic basis of C1 inhibitor (C1 INH) deficiency in a patient with type I hereditary angioneurotic edema was studied. This patient was found to have an abnormally short C1 INH mRNA together with a normal message. Restriction fragment length polymorphism of the C1 INH gene was detected by Southern blot analysis of the patient's DNA after digestion with Pst I or Sac I, and hybridization with a full-length C1 INH cDNA. Hybridization of the same blot with three different fragments of the full-length cDNA suggested that exon VII and portions of both flanking introns were deleted in the C1 INH gene. Northern blot analysis of RNA from cultured monocytes, using a probe corresponding to exon VII, also indicated that the abnormal C1 INH mRNA had a deletion of these nucleotides. To confirm the hypothesis that the short C1 INH mRNA contained a deletion, the involved segment of the patient's C1 INH mRNA was amplified using the polymerase chain reaction (PCR). PCR amplification yielded two C1 INH DNA fragments of different lengths (380 and 160 bp). Southern blot and sequence analysis of both DNA fragments clearly revealed that the smaller 160-bp DNA was derived from the abnormal message and had a deletion of nucleotides corresponding to exon VII.

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.

Extracorporeal membrane oxygenation and conventional medical therapy in neonates with persistent pulmonary hypertension of the newborn: a prospective randomized study.

Thirty-nine newborn infants with severe persistent pulmonary hypertension and respiratory failure who met criteria for 85% likelihood of dying were enrolled in a randomized trial in which extracorporeal membrane oxygenation (ECMO) therapy was compared with conventional medical therapy (CMT). In phase I, 4 of 10 babies in the CMT group died and 9 of 9 babies in the ECMO group survived. Randomization was halted after the fourth CMT death, as planned before initiating the study, and the next 20 babies were treated with ECMO (phase II). Of the 20, 19 survived. All three treatment groups (CMT and ECMO in phase I and ECMO, phase II) were comparable in severity of illness and mechanical ventilator support. The overall survival of ECMO-treated infants was 97% (28 of 29) compared with 60% (6 of 10) in the CMT group (P less than .05).

Randomized controlled trial of exogenous surfactant for the treatment of hyaline membrane disease.

We conducted a prospective, randomized, unblinded, controlled trial of exogenous bovine surfactant (surfactant TA) in premature infants requiring ventilator support for the treatment of severe hyaline membrane disease. Forty-one low birth weight infants with severe hyaline membrane disease were randomly assigned to saline or surfactant therapy and treated within eight hours of birth. Significant improvements in oxygenation (increased arterial/alveolar PO2) and respiratory support (decreased mean airway pressure) were seen in the group receiving surfactant within four hours after treatment. These improvements were maintained in the surfactant-treated infants, who also had fewer pneumothoraces and fewer number of days in environments of fractional inspiratory oxygen greater than 0.4 mm Hg. No problems were associated with administration of surfactant, and no acute side effects were detected. We conclude that exogenous surfactant, administered early in the course of severe hyaline membrane disease, is an effective therapy that can diminish the amount of respiratory support required during the first 48 hours of life.

Exogenous surfactant therapy in hyaline membrane disease.

Exogenous surfactant therapy appears to offer promise in the treatment and possible prevention of HMD. Laboratory investigations have begun to reveal the molecular basis for surfactant metabolism and the relationship of this complex process to alveolar stability and pulmonary function. There is every reason to encourage clinical investigation with surfactant therapy in parallel with further basic research. Nevertheless, pediatricians must proceed in small steps with carefully designed studies to address specific questions regarding both efficacy and toxicity. Results from various studies must be shared and discussed and every attempt must be made to eventually provide standardized, readily available preparations of known efficacy and toxicity. Efforts by many investigators make it seem probable that this goal will be achieved in the near future.

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.

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.

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.

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.

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.

Prevalence of cystic fibrosis in fetuses with dilated bowel.

The authors reviewed the ultrasonographic images and medical records of 15 consecutive fetuses with dilated loops of bowel distal to the duodenum and determined the prevalence of cystic fibrosis among them. The criteria for dilated bowel loops included both subjective criteria and luminal measurements. Five of the fetuses (33%) had cystic fibrosis. Eleven had bowel obstruction at birth, and four of those 11 (36%) also had cystic fibrosis. One of the four fetuses without bowel obstruction at birth had cystic fibrosis. There were no differences in sonographic findings between fetuses with and without cystic fibrosis, except that one third-trimester fetus with cystic fibrosis had echogenic small bowel with shadowing. All of the fetuses with dilated bowel loops persisting at birth required surgery. Further studies are indicated to determine the exact risk of cystic fibrosis in this population.

The natural history of isolated fetal hydrothorax.

We reviewed the prenatal course and outcome of 11 fetuses with isolated unilateral or bilateral hydro thoraces identified between 14 and 34 weeks' gestation, in the absence of invasive fetal intervention. Four of these fetuses died, three in utero and one in the newborn period. Six of seven survivors had resolution of hydrothorax before birth. Eight of the 11 fetuses had unilateral and three bilateral hydrothoraces. Six of the eight fetuses with unilateral hydrothorax survived, whereas one of the three with bilateral hydrothoraces lived. Six of the 11 pregnancies were complicated by polyhydramnios; four of these six fetuses died. One fetus was found to have trisomy 21. It is difficult to draw firm conclusions from the small number of patients in this report because of the wide range of outcomes found for the sonographic variables described. This series shows, however, a tendency to complete resolution of primary unilateral fetal hydrothorax, with good outcome, particularly in second-trimester fetuses without polyhydramnios.

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.

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.

Dysfunctional C1 inhibitor Ta: deletion of Lys-251 results in acquisition of an N-glycosylation site.

Hereditary angioneurotic edema is inherited as an autosomal dominant disorder and is characterized by potentially life-threatening episodic angioedema. In type II hereditary angioneurotic edema, a dysfunctional C1 inhibitor molecule is present together with low levels of normal C1 inhibitor. About 70% of these dysfunctional proteins result from reactive center (Arg-444) mutations. We describe the deletion of nucleotides encoding Lys-251 (AAG) in C1 inhibitor Ta, the dysfunctional C1 inhibitor from a family with type II hereditary angioneurotic edema. DNA sequence analysis was derived from clones obtained through polymerase chain reaction amplification of blood monocyte C1 inhibitor mRNA. As expected, clones with both normal and abnormal sequence were isolated. The deletion was verified by protein sequence analysis. These data, together with biochemical analysis of the protein and cell-free translation studies, suggest that this deletion, by altering the normal amino acid sequence from Asn-Lys-Ile-Ser to Asn-Ile-Ser, creates a new glycosylation site. The additional carbohydrate accounts for the larger size on SDS/PAGE and very likely interferes with protein function.