Features of transient hypogammaglobulinaemia in infants screened for immunological abnormalities.

The incidence of transient hypogammaglobulinaemia of infancy (THI) detected in a major paediatric centre over a 10 year period was examined. A total of 2468 subjects less than 2 years of age had an IgG measurement taken between July 1979 and March 1990. Subjects with known immunodeficiencies were excluded. Fifteen patients were classified as having THI with an initial IgG level less than the fifth centile followed by a second measurement within the normal range. A further 24 patients were identified as having possible THI with a single low IgG concentration. There were 60,174 live births each year in Victoria in the years 1979-88. This gives an incidence of proved THI of 23 per 10(6) births, and including proved and probable THI an incidence of 61 per 10(6) live births. Of those patients with proved THI 12/15 had symptoms of either atopic disease or food allergy/intolerance and three had gastrointestinal symptoms without any evidence of atopic disease. At presentation 12/15 (80%) were IgA deficient and 9/15 had IgM concentrations less than the 20th centile for age. It is suggested that in view of the preponderance of atopic and food intolerant patients that subclinical protein loss from the bowel due to allergic inflammation may be a contributing factor to the development of THI in some patients.     

HLA-haploidentical bone marrow transplantation in three infants with adenosine deaminase deficiency: Stable immunological reconstitution and reversal of skeletal abnormalities

Three infants with severe combined immunodeficiency and adenosine deaminase (ADA) deficiency were treated by T-cell depleted bone marrow transplantation (BMT), using human leukocyte antigen (HLA)-haploidentical parents as donors. In the first patient, two initial transplants failed to engraft and no change of the immunodeficiency was observed. In order to overcome this graft resistance, cytoreductive conditioning was used prior to a third transplant. In the other two patients, similar conditioning was used prior to initial transplants. In all three patients, complete and permanent immunological reconstitution was observed and they survive from 3.5 to 5 years after transplantation. In biopsies obtained from iliac bones prior to BMT, osteochondral abnormalities characteristic of ADA-deficiency were noted in all three patients. After successful transplantation, these abnormalities had completely resolved. Our results demonstrate that cytoreductive conditioning prior to HLA-haploidentical BMT is useful in order to obtain stable engraftment and reversal of abnormalities associated with ADA deficiency.     

Ultrasound screening of healthy infants for urinary tract abnormalities

The purpose of the study was to determine the incidence of silent but significant urinary tract abnormalities that might be detected by screening renal ultrasound studies of apparently healthy infants. Of 437 babies studied, six were found to have uropathology severe enough to warrant surgery for an incidence of 1.37% or one of every 73 babies studied.     

Evolution of immunological abnormalities in HIV infection by vertical transmission

Forty-four children infected through vertical transmission, from a total of 146 born to HIV-positive mothers, were studied. Immunological data were analysed and compared with those of the non-infected children. Two transmission patterns emerge from the clinical and immunological characteristics: (i) infants infected during pregnancy with severe immunodeficiency and clinical manifestations before the age of 1 year, and (ii) children probably infected perinatally, who have better clinical outcome. Immunological data are important for prognosis and early therapeutic protocols to be established.     

Frequency and timing of symptoms in infants screened for sepsis: effectiveness of a sepsis-screening pathway

To determine the frequency and timing of symptoms and to evaluate the effectiveness of a sepsis-screening pathway in term and near-term infants, data were collected prospectively for a period of 1 year from December 1, 2000, to November 30, 2001. Results confirmed that a sepsis-screening pathway using a combination of at least 2 serial complete blood cell count and C-reactive protein measurements in both symptomatic and asymptomatic infants is a safe, simple strategy that prevents unnecessary treatment of infants with risk factors with antibiotics. However, most infants with presumed or suspected early-onset sepsis are symptomatic. Routine treatment of asymptomatic infants with risk factors or prior treatment with intrapartum antibiotics is unnecessary. A combined approach of screening in the presence of risk factors and /or symptoms of sepsis and adequate follow-up for infants discharged at less than 72 hours of age may help reduce unnecessary treatment of infants with antibiotics.     

Tracheobronchial abnormalities in infants with bronchopulmonary dysplasia

Twelve preterm infants with bronchopulmonary dysplasia underwent bronchoscopy to determine if airway abnormalities were contributing to persistent pulmonary problems. Indications for bronchoscopy were persistent atelectasis, lobar hyperinflation, or both on chest radiograph (11 patients), unexplained respiratory distress (three patients), and aspiration of tissuelike material from a tracheostomy (one patient). Bronchoscopy revealed abnormalities of the trachea, bronchi, or both in all infants, including partial or near total airway occlusion by abnormal growth of tissue (10 patients); tracheomalacia, bronchomalacia, or both (three patients); and inspissated secretions (two patients). Seven infants died during initial hospitalization. Tracheobronchial abnormalities should be considered as a cause of persistent pulmonary problems in infants with bronchopulmonary dysplasia.     

Echocardiographic abnormalities in infants of diabetic mothers.

In order to evaluate the presence of myocardial hypertrophy and/or abnormalities of postnatal cardiovascular adaptation, echocardiograms were performed on 34 infants of diabetic mothers. Based on cardiopulmonary assessment, the IDM were divided into three groups: Group I with congestive heart failure predominating: Group II with respiratory distress predominating: Group III asymptomatic. Hypertrophy of the interventricular septum and of the walls of left and right ventricles was frequently present in IDM: this change was most notable in association with clinical CHF. Six IDM, four of whom were found to have CHF, had additional echocardiographic signs of subaortic stenosis. All IDM had normal indices of left ventricular performance, despite the presence of CHE. In IDM with respiratory distress, the right ventricular pre-ejection period to ventricular ejection time ratio was elevated, suggesting an abnormality of the transitional pulmonary circulation. Poor maternal diabetes control and maternal systemic hypertension were closely correlated with evidence of myocardial hypertrophy in the infants.     

早产儿暂时性甲状腺功能减退研究进展

早产儿暂时性甲状腺功能减退表现为出生后的暂时性低甲状腺素血症,其程度与胎龄和出生体重有关.低甲状腺素血症可影响多种器官功能,其中以神经系统发育受影响为主,其治疗目前尚无统一结论.近年研究发现,甲状腺素补充治疗对于胎龄小于27周的早产儿有效,可改善远期神经系统预后.该文对早产儿暂时性甲状腺功能减退的病因、分型、临床表现、治疗方面的研究进展进行综述.     

Thyroxine for transient hypothyroxinemia and cerebral palsy in extremely preterm infants

Background: The relationship of thyroxine supplementation for transient hypothyroxinemia of prematurity to the incidence of cerebral palsy (CP) in infants <28 weeks of gestation is unclear. Methods: The incidence of CP at a corrected age of 18 months was compared between infants born in a 3‐year period in which routine measurement of free T4 (FT4) in the blood was not performed (first period, n= 54), and those born in a later 3‐year period in which FT4 was measured (second period, n= 60; mainly at 7 days old), and in which l ‐thyroxine 5–10 µg/kg per day (mean, 9 µg/kg/day) was administered for FT4 levels <0.8 ng/dL. Incidence of CP at 3 years of age was also compared between the same groups. Results: Background clinical factors between the two groups were comparable except for prenatal steroid administration, which was reduced in the second period. Incidence of CP at a corrected age of 18 months was significantly lower in the second period (3.3%) than in the first period (16.6%). Incidence of CP at 3 years of age was also significantly lower in the second period. Multiple logistic regression analysis using factors except thyroxine supplementation, for the total of 114 infants from both groups, found no perinatal factors related to the development of CP at a corrected age of 18 months. Conclusions: Thyroxine supplementation for transient hypothyroxinemia of prematurity may reduce the incidence of CP in extremely preterm infants. Large‐scale randomized controlled trials are essential to determine the effects of thyroxine supplementation in reducing the incidence of CP among extremely preterm infants.     

Evidence for transient peripheral resistance to parathyroid hormone in premature infants

Serum immunoreactive parathyroid hormone (iPTH), ionized calcium, the urinary cyclic AMP/creatinine ratio (cAMP/Cr) and some indices of bone turnover (alkaline phosphatase (AP), serum osteocalcin, and the urinary total hydroxyproline/creatinine ratio (OH-P/Cr)) were measured in 26 preterm infants during the first 4 weeks of life. Despite of stimulated parathyroid gland activity cAMP/Cr, AP, osteocalcin and OH-P/Cr were low during the first week. Thereafter iPTH decreased, whereas cAMP/Cr, and the indices of bone turnover increased, reaching high-normal values (in comparison to full-term infants) during the second and third week of life. Serum iPTH was negatively correlated to cAMP/Cr in the first week (r = -0.61, p less than 0.01), whereas the relationship became positive during the second (r = 0.47, p less than 0.05) and third (r = 0.54, p less than 0.05) week of life indicating maturation of the renal response to PTH. The study supports the concept that in premature infants a transient pseudohypoparathyroid-like state is present during the first week of life reflecting an immaturity of renal and possibly bone response to PTH. This may be an etiological factor in hypocalcemia of prematurity.     

Lymphocyte abnormalities in infants born to drug-abusing mothers

To evaluate the possible effects of maternal intravenous drug use on infant immunity, we measured the in vitro peripheral blood mononuclear cell proliferative responses to phytohemagglutinin (PHA) and pokeweed mitogen, T cell subset numbers, immunoglobulin levels, and titers of antibodies to cytomegalovirus (CMV) and human immunodeficiency virus (HIV) in a group of drug-abusing mothers and their infants. Infants of drug abusers had a lower proliferative response to mitogen, associated with altered kinetics of the maximum response to PHA. The OKT4/OKT8 ratio decreased with age in the drug-exposed infants compared with control infants (P less than 0.005). There was no evidence of CMV infection in either group. One mother and her infant had antibody to HIV. Our data demonstrate that infants of intravenous drug-using mothers have distinct immunologic differences at birth compared with non-drug-exposed infants and that these persist throughout the first year of life. The cause appears unrelated to intrauterine viral infection, suggesting a direct toxic effect of the drugs on fetal immunologic development.     

Cardiovascular abnormalities in infants prenatally exposed to cocaine

This study utilized a historical cohort to examine the relationship between maternal cocaine use during pregnancy and the occurrence of congenital cardiovascular abnormalities. All neonatal drug screens performed at Boston City Hospital during an 18-month period were reviewed (n = 554); for 214 (39%) screened high-risk neonates, results of toxicologic screens were positive for cocaine, and 340 (61%) neonates had no detectable cocaine. We compared the occurrence of cardiovascular malformations and electrocardiographic abnormalities in these two groups. Matches were sought between these 554 infants and our pediatric cardiology data base, which consisted of inpatient consultation, outpatient consultation, and electrocardiography. Forty-nine patients had drug screens and were also entered into our cardiology data base: 25 had both consultations and electrocardiograms, and 24 had electrocardiograms only. The rate of cardiac anomalies among the cocaine-positive infants was significantly higher (relative risk = 3.7; 95% confidence interval: (1.4, 9.4)) than the rate of these anomalies among the cocaine-negative comparison group (65/100 vs 18/1000); the rate for cocaine-positive infants was also significantly higher than published rates for general populations of infants. Several electrocardiographic abnormalities, high-grade ventricular ectopy, and cardiorespiratory arrests were also noted in our study population. We conclude that cocaine exposure during prenatal life appears to predispose infants to structural cardiovascular malformations, electrocardiographic abnormalities, and, possibly, cardiopulmonary autonomic dysfunction.     

Surfactant abnormalities in infants with severe viral bronchiolitis

To determine whether abnormalities of pulmonary surfactant occur in infants with acute viral bronchiolitis, surfactant indices were measured in lung lavage fluid from 12 infants with severe bronchiolitis and eight infants without lung disease. Compared with controls, the bronchiolitis group showed deficiency of surfactant protein A (1.02 v 14.4 micrograms/ml) and disaturated phosphatidylcholine (35 v 1060 micrograms/ml) which resolved as the disease improved. Surfactant functional activity was also impaired (minimum surface tension 22 v 17 mN/m). These findings indicate that surfactant abnormalities occur in bronchiolitis, and may represent one of the pathophysiological mechanisms causing airway obstruction.