Systemic Corticosteroid-Related Complications and Costs in Adults with Persistent Asthma

BACKGROUND

Systemic corticosteroids (SCS) may cause complications for patients with asthma.

OBJECTIVE

We sought to better understand the burden of SCS use in persistent asthma, including health care costs.

METHODS

Adult patients with persistent asthma were identified in the IBM MarketScan Databases from January 2003 to July 2016. The index date was set as the first SCS prescription for SCS users or an algorithm-matched date for non-SCS users. Patients were required to have ≥1 year of data before and after the index date. Based on the number of SCS claims in the first year after index, patients were categorized into 3 SCS groups: 0 SCS claims, 1 to 3 claims, and 4+ claims. Inverse probability of treatment weights were applied to adjust for differences between SCS and non-SCS users. Analyses included weighted and multivariate modeling to assess SCS-related complications and costs during a 3-year follow-up.

RESULTS

A total of 86,786 SCS users (1-3 claims: 76,690; 4+ claims: 10,096) and 91,409 non-SCS users were included; 45% remained 3 years after index. In multivariate analysis, the 3-year risk of developing any chronic complication was 6% greater for those with 1 to 3 claims and 26% greater for those with 4+ claims compared with non-SCS users (P < .001). Multivariate-adjusted health care costs over 3 years were significantly greater as 4+ users incurred $22,311 greater total costs, $4627 greater asthma-related costs, and $2647 greater chronic complication-related costs than non-SCS users (P < .001).

CONCLUSIONS

In this study, adults with persistent asthma receiving SCS treatment had greater odds of complications and greater associated costs over 3 years than matched non-SCS asthma patients.

Association of the Infant Gut Microbiome With Early Childhood Neurodevelopmental Outcomes: An Ancillary Study to the VDAART Randomized Clinical Trial

IMPORTANCE

In animal models, the early life gut microbiome influences later neurodevelopment. Corresponding data in human populations are lacking.

OBJECTIVE

To study associations between the gut microbiome in infants and development at preschool age measured by the Ages and Stages Questionnaire, third edition (ASQ-3).

DESIGN, SETTING, AND PARTICIPANTS

This ancillary cohort study of the Vitamin D Antenatal Asthma Reduction Trial (VDAART) used data from 715 participants who had development assessed at 3 years of age by the ASQ-3, which included scores in 5 domains (gross motor skills, fine motor skills, problem solving, communication, and personal and social skills). A total of 309 stool samples were collected from infants aged 3 to 6 months for microbiome analysis using 16S rRNA gene sequencing.

EXPOSURES

Infant gut microbiome.

MAIN OUTCOMES AND MEASURES

Continuous ASQ-3 scores and typical vs potential delay in the 5 developmental domains. Factor scores for bacterial coabundance groups were used as predictors in regression models of continuous ASQ-3 scores. Logistic regression was used to examine bacterial coabundance scores and odds of scoring below the threshold for typical development. Multivariate analysis examined the abundance of individual taxa and ASQ-3 scores.

RESULTS

The 309 participants (170 [55.0%] male) with ASQ-3 scores and stool samples were ethnically diverse (136 [44.0%] black, 41 [13.3%] Hispanic, 86 [27.8%] white, and 46 [14.9%] other race/ethnicity); the mean (SD) age at ASQ-3 assessment was 3.0 (0.07) years. Coabundance scores dominated by Clostridiales (Lachnospiraceae genera and other, unclassified Clostridiales taxa) were associated with poorer ASQ-3 communication (β, -1.12; 95% CI, -2.23 to -0.01; P = .05) and personal and social (β, -1.44; 95% CI, -2.47 to -0.40; P = .01) scores and with increased odds of potential delay for communication (odds ratio [OR], 1.69; 95% CI, 1.06 to 2.68) and personal and social skills (OR, 1.96; 95% CI, 1.22 to 3.15) per unit increase in coabundance score. The Bacteroides-dominated coabundance grouping was associated with poorer fine motor scores (β, -2.42; 95% CI, -4.29 to -0.55; P = .01) and with increased odds of potential delay for fine motor skills (OR, 1.52; 95% CI, 1.07 to 2.16) per unit increase in coabundance score. Multivariate analysis detected similar family-level and order-level associations.

CONCLUSIONS AND RELEVANCE

These findings suggest an association between infant gut microbiome composition and communication, personal and social, and fine motor skills at age 3 years. The majority of associations were driven by taxa within the order Clostridiales.

Impact of parental asthma, prenatal maternal asthma control, and vitamin D status on risk of asthma and recurrent wheeze in 3-year-old children

BACKGROUND

While familial clustering of asthma is known, few studies have reported on the relative roles of paternal and maternal asthma and the role of maternal asthma control in pregnancy on the risk for asthma in the child.

OBJECTIVE

We aimed to investigate the relative roles of paternal asthma, maternal asthma, and maternal asthma control during pregnancy on the risk of asthma or recurrent wheeze in 3-year-old children and how prenatal and cord blood vitamin D status might affect this risk.

METHODS

Data from 806 women, their partners (biologic fathers of the infants), and their children participated in the Vitamin D Antenatal Asthma Reduction Trail (VDAART, clinicaltrials.gov identification number NCT00920621) were used for this cohort analysis. The parental report of physician-diagnosed asthma or recurrent wheeze in offspring was the main outcome. Weibull regression models for interval-censored event times were used to estimate the main variables of interests and additional covariates on the outcome.

RESULTS

The highest risk was observed among children with both parents being asthmatic relative to non-asthmatic parents (aHR = 2.30, 95% CI: 1.35-3.84), and less so if only the mother was asthmatic (aHR = 1.70, 95% CI: 1.17-2.40). In the subset of children born to asthmatic mothers, the risk for asthma was higher in those who were born to mothers whose asthma was uncontrolled (aHR = 1.60, 95% CI: 1.02-2.54). Children whose mothers had sufficient vitamin D status (25Hydroxyvitamin D ≥ 30 ng/mL) at early and late pregnancy and had cord blood vitamin D sufficiency demonstrated a lower risk of asthma/recurrent wheeze than children who had insufficient cord blood vitamin D status at birth (aHR = 0.47, 95% CI: 0.27-0.83).

CONCLUSION AND CLINICAL RELEVANCE

Careful attention to maternal asthma control, monitoring vitamin D status, and correcting insufficiency at early pregnancy and maintaining the sufficiency status throughout pregnancy have potential preventive roles in offspring asthma or recurrent wheeze.

Diet during Pregnancy and Infancy and the Infant Intestinal Microbiome

OBJECTIVES

To determine the association between diet during pregnancy and infancy, including breastfeeding vs formula feeding, solid food introduction, and the infant intestinal microbiome.

STUDY DESIGN

Infants participating in the Vitamin D Antenatal Asthma Reduction Trial were included in this study (n = 323). Maternal and infant diets were assessed by questionnaire. Infant stool samples were collected at age 3-6 months. Stool sequencing was performed using the Roche 454 platform. Analyses were stratified by race/ethnicity.

RESULTS

Breastfeeding, compared with formula feeding, was independently associated with infant intestinal microbial diversity. Breastfeeding also had the most consistent associations with individual taxa that have been previously linked to early-life diet and health outcomes (eg, Bifidobacterium). Maternal diet during pregnancy and solid food introduction were less associated with the infant gut microbiome than breastfeeding status. We found evidence of a possible interaction between breastfeeding and child race/ethnicity on microbial composition.

CONCLUSIONS

Breastfeeding vs formula feeding is the dietary factor that is most consistently independently associated with the infant intestinal microbiome. The relationship between breastfeeding status and intestinal microbiome composition varies by child race/ethnicity. Future studies will need to investigate factors, including genomic factors, which may influence the response of the microbiome to diet.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00920621.

A prospective microbiome-wide association study of food sensitization and food allergy in early childhood

BACKGROUND

Alterations in the intestinal microbiome are prospectively associated with the development of asthma; less is known regarding the role of microbiome alterations in food allergy development.

METHODS

Intestinal microbiome samples were collected at age 3-6 months in children participating in the follow-up phase of an interventional trial of high-dose vitamin D given during pregnancy. At age 3, sensitization to foods (milk, egg, peanut, soy, wheat, walnut) was assessed. Food allergy was defined as caretaker report of healthcare provider-diagnosed allergy to the above foods prior to age 3 with evidence of IgE sensitization. Analysis was performed using Phyloseq and DESeq2; P-values were adjusted for multiple comparisons.

RESULTS

Complete data were available for 225 children; there were 87 cases of food sensitization and 14 cases of food allergy. Microbial diversity measures did not differ between food sensitization and food allergy cases and controls. The genera Haemophilus (log2 fold change -2.15, P=.003), Dialister (log2 fold change -2.22, P=.009), Dorea (log2 fold change -1.65, P=.02), and Clostridium (log2 fold change -1.47, P=.002) were underrepresented among subjects with food sensitization. The genera Citrobacter (log2 fold change -3.41, P=.03), Oscillospira (log2 fold change -2.80, P=.03), Lactococcus (log2 fold change -3.19, P=.05), and Dorea (log2 fold change -3.00, P=.05) were underrepresented among subjects with food allergy.

CONCLUSIONS

The temporal association between bacterial colonization and food sensitization and allergy suggests that the microbiome may have a causal role in the development of food allergy. Our findings have therapeutic implications for the prevention and treatment of food allergy.

Early pregnancy vitamin D status and risk of preeclampsia

BACKGROUND

Low vitamin D status in pregnancy was proposed as a risk factor of preeclampsia.

METHODS

We assessed the effect of vitamin D supplementation (4,400 vs. 400 IU/day), initiated early in pregnancy (10-18 weeks), on the development of preeclampsia. The effects of serum vitamin D (25-hydroxyvitamin D [25OHD]) levels on preeclampsia incidence at trial entry and in the third trimester (32-38 weeks) were studied. We also conducted a nested case-control study of 157 women to investigate peripheral blood vitamin D-associated gene expression profiles at 10 to 18 weeks in 47 participants who developed preeclampsia.

RESULTS

Of 881 women randomized, outcome data were available for 816, with 67 (8.2%) developing preeclampsia. There was no significant difference between treatment (N = 408) or control (N = 408) groups in the incidence of preeclampsia (8.08% vs. 8.33%, respectively; relative risk: 0.97; 95% CI, 0.61-1.53). However, in a cohort analysis and after adjustment for confounders, a significant effect of sufficient vitamin D status (25OHD ≥30 ng/ml) was observed in both early and late pregnancy compared with insufficient levels (25OHD <30 ng/ml) (adjusted odds ratio, 0.28; 95% CI, 0.10-0.96). Differential expression of 348 vitamin D-associated genes (158 upregulated) was found in peripheral blood of women who developed preeclampsia (FDR <0.05 in the Vitamin D Antenatal Asthma Reduction Trial [VDAART]; P < 0.05 in a replication cohort). Functional enrichment and network analyses of this vitamin D-associated gene set suggests several highly functional modules related to systematic inflammatory and immune responses, including some nodes with a high degree of connectivity.

CONCLUSIONS

Vitamin D supplementation initiated in weeks 10-18 of pregnancy did not reduce preeclampsia incidence in the intention-to-treat paradigm. However, vitamin D levels of 30 ng/ml or higher at trial entry and in late pregnancy were associated with a lower risk of preeclampsia. Differentially expressed vitamin D-associated transcriptomes implicated the emergence of an early pregnancy, distinctive immune response in women who went on to develop preeclampsia.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00920621.

FUNDING

Quebec Breast Cancer Foundation and Genome Canada Innovation Network. This trial was funded by the National Heart, Lung, and Blood Institute. For details see Acknowledgments.

Factors influencing the infant gut microbiome at age 3-6 months: Findings from the ethnically diverse Vitamin D Antenatal Asthma Reduction Trial (VDAART)

BACKGROUND

The gut microbiome in infancy influences immune system maturation, and may have an important impact on allergic disease risk.

OBJECTIVE

We sought to determine how prenatal and early life factors impact the gut microbiome in a relatively large, ethnically diverse study population of infants at age 3 to 6 months, who were enrolled in Vitamin D Antenatal Asthma Reduction Trial, a clinical trial of vitamin D supplementation in pregnancy to prevent asthma and allergies in offspring.

METHODS

We performed 16S rRNA gene sequencing on 333 infants' stool samples. Microbial diversity was computed using the Shannon index. Factor analysis applied to the top 25 most abundant taxa revealed 4 underlying bacterial coabundance groups; the first dominated by Firmicutes (Lachnospiraceae/Clostridiales), the second by Proteobacteria (Klebsiella/Enterobacter), the third by Bacteriodetes, and the fourth by Veillonella. Scores for coabundance groups were used as outcomes in regression models, with prenatal/birth and demographic characteristics as independent predictors. Multivariate analysis, using all microbial community members, was also conducted.

RESULTS

White race/ethnicity was associated with lower diversity but higher Bacteroidetes coabundance scores. C-section birth was associated with higher diversity, but decreased Bacteroidetes coabundance scores. Firmicutes scores were higher for infants born by C-section. Breast-fed infants had lower proportions of Clostridiales. Cord blood vitamin D was linked to increased Lachnobacterium, but decreased Lactococcus.

CONCLUSIONS

The findings presented here suggest that race, mode of delivery, breast-feeding, and cord blood vitamin D levels are associated with infant gut microbiome composition, with possible long-term implications for immune system modulation and asthma/allergic disease incidence.

Development and cross-sectional validation of the Childhood Asthma Control Test

BACKGROUND

For children younger than 12 years old with asthma, there are several quality-of-life instruments, clinical diaries, and questionnaires assessing symptoms; however, a validated tool for assessing asthma control is currently lacking.

OBJECTIVE

To develop and validate the Childhood Asthma Control Test (C-ACT), a self-administered tool for identifying children aged 4-11 years whose asthma is inadequately controlled.

METHODS

A 21-item questionnaire was administered to 343 patients with asthma and their caregivers, randomly assigning 75% (n = 257) for development and cross-sectional validation of the tool and 25% (n = 86) to a confirmatory sample. Stepwise logistic regression was used to reduce the 21 items to those best able to discriminate control as defined by the specialist's rating of asthma control.

RESULTS

Seven items were selected from regression analyses of the development sample to comprise the C-ACT. The scores of each item were summed for a total score (0-27), with lower scores indicating poorer control. Summed scores discriminated between groups of patients differing in the specialists' rating of asthma control (F = 36.89; P < .0001), the need for change in patients' therapy (F = 20.07; P < .0001), and % predicted FEV(1) (F = 2.66; P = .0494). A score of 19 indicated inadequately controlled asthma (specificity 74%, sensitivity 68%). These analyses were confirmed in the confirmatory sample.

CONCLUSION

The C-ACT is a validated tool to assess asthma control and identify children with inadequately controlled asthma.

CLINICAL IMPLICATIONS

The C-ACT can be valuable in clinical practice and research based on its validation, ease of use, input from the child and caregiver, and alignment with asthma guidelines.

The prevalence of reversible airflow obstruction and/or methacholine hyperreactivity in random adult asthma patients identified by administrative data

BACKGROUND

Asthma is a chronic inflammatory lung disease. It is commonly diagnosed and treated on the basis of clinical impression, although national guidelines recommend documenting reversible airflow obstruction.

OBJECTIVES

Determine the frequency of reversible airflow obstruction, and/or methacholine hyperreactivity during 2003 in a well-characterized population with a low-risk asthma diagnosis during 2001.

METHODS

Of a total population of 7460 low-risk adult (18-64 years) asthma patients (no hospitalizations or emergency department visits; < 3 oral steroid courses; < 12 beta-agonist canisters; and < 3 prescibers, all in prior 12 months) cared for by a large health care program, a random sample of 400 was recruited to undergo a diagnostic asthma evaluation. The evaluation included a physical examination, medical record review, questionnaires, allergy testing, spirometry for airflow obstruction and reversibility, and/or methacholine hyperreactivity.

RESULTS

Of the 400 randomly selected patients, 106 (26.5%) started and 82 (77.3%) completed the asthma evaluation. Evaluated subjects were predominately female (71%), middle-aged (mean 51.0 +/- 11.0 years), diagnosed asthmatics for long duration (mean 22.1 +/- 17.5 years), and nonsmokers (88.7%). Asthma was confirmed in 62.1% (51 of 82) based on a deltaFEV1 12% or greater after albuterol (n = 38), deltaFEV1 15% or greater after Advair (n = 6), or a positive methacholine challenge (n = 7). Only 35 of 400 patients (8.7%) ever had reversibility measured in their medical record. Of these, only 12 (34.3%) had a deltaFEV1 12% or greater after albuterol. Reversibility was confirmed in all six who had asthma evaluations.

CONCLUSIONS

More than one third of low-risk adult asthmatics cannot be confirmed to have asthma 2 years later. Spirometry that documented reversibility in the medical record accurately predicted asthma confirmation. Physicians should more widely perform spirometry with reversibility to establish the diagnosis of asthma as recommended by national asthma guidelines.

Long-term effects of budesonide or nedocromil in children with asthma

BACKGROUND

Antiinflammatory therapies, such as inhaled corticosteroids or nedocromil, are recommended for children with asthma, although there is limited information on their long-term use.

METHODS

We randomly assigned 1041 children from 5 through 12 years of age with mild-to-moderate asthma to receive 200 microg of budesonide (311 children), 8 mg of nedocromil (312 children), or placebo (418 children) twice daily. We treated the participants for four to six years. All children used albuterol for asthma symptoms.

RESULTS

There was no significant difference between either treatment and placebo in the primary outcome, the degree of change in the forced expiratory volume in one second (FEV1, expressed as a percentage of the predicted value) after the administration of a bronchodilator. As compared with the children assigned to placebo, the children assigned to receive budesonide had a significantly smaller decline in the ratio of FEV1 to forced vital capacity (FVC, expressed as a percentage) before the administration of a bronchodilator (decline in FEV1:FVC, 0.2 percent vs. 1.8 percent). The children given budesonide also had lower airway responsiveness to methacholine, fewer hospitalizations (2.5 vs. 4.4 per 100 person-years), fewer urgent visits to a caregiver (12 vs. 22 per 100 person-years), greater reduction in the need for albuterol for symptoms, fewer courses of prednisone, and a smaller percentage of days on which additional asthma medications were needed. As compared with placebo, nedocromil significantly reduced urgent care visits (16 vs. 22 per 100 person-years) and courses of prednisone. The mean increase in height in the budesonide group was 1.1 cm less than in the placebo group (22.7 vs. 23.8 cm, P=0.005); this difference was evident mostly within the first year. The height increase was similar in the nedocromil and placebo groups.

CONCLUSIONS

In children with mild-to-moderate asthma, neither budesonide nor nedocromil is better than placebo in terms of lung function, but inhaled budesonide improves airway responsiveness and provides better control of asthma than placebo or nedocromil. The side effects of budesonide are limited to a small, transient reduction in growth velocity.

Construction and validation of four childhood asthma self-management scales: parent barriers, child and parent self-efficacy, and parent belief in treatment efficacy

This study examined the psychometric properties of four new health belief measures for asthmatic children and their parents. A total of 110 asthmatic children (aged 7-15) and 129 parents (with asthmatic children aged 3-15) responded to a mail-out survey. Evidence for reliability (0.75-0.87) and validity was obtained for measures of Parent Barriers to Managing Asthma, Parent Asthma Self-Efficacy (subscales: attack prevention and attack management), Parent Treatment Efficacy, and Child Asthma Self-Efficacy (subscales: attack prevention and attack management). All measures were correlated in the hypothesized directions with health status, asthma symptoms, and impact of illness on the family.

Skin testing with penicilloate and penilloate prepared by an improved method: amoxicillin oral challenge in patients with negative skin test responses to penicillin reagents

BACKGROUND

Penicillin skin testing has been limited by the lack of commercially available penicilloate and penilloate reagents.

OBJECTIVE

This project was proposed to produce a stable, well-characterized supply of penicilloate and penilloate for intrastate use by our health maintenance organization and to document clinical safety and efficacy.

METHODS

An improved method of extraction for penicilloate and penilloate, which changed the solvents used during recrystallization, was developed. With these newly prepared reagents, penicillin skin testing was performed on 348 subjects. Skin testing was immediately followed by an oral challenge of 250 mg of amoxicillin in 215 of 288 (75%) subjects displaying a negative response to a battery of penicillin skin tests.

RESULTS

Nuclear magnetic resonance and mass spectrometry of the newly produced penicilloate and penilloate showed no evidence of organic contamination. Penicillin skin testing resulted in 17.2% (60 of 348) positive test results, with 20% of the subjects with positive results only responding to the newly produced minor determinants. The rate of mild adverse reactions to penicillin skin testing was 1.1% (4 of 348). The rate of mild acute adverse reactions was 5.1% (11 of 215), and the delayed reaction rate was 0.9% (2 of 215) with the amoxicillin challenge.

CONCLUSIONS

This improved penicillin minor determinant extraction method allows for the reproducible production of very pure preparations of penicilloate and penilloate. Large-scale penicillin skin testing, followed by amoxicillin challenge if results are negative is feasible in a large group model health maintenance organization operating within a single state with the use of internally produced penicilloate and penilloate and commercially available penicillin, amoxicillin, and penicilloyl polylysine.

Structural and functional properties of the coleoptile chloroplast: Photosynthesis and photosensory transduction

Recent studies have shown that guard cell and coleoptile chloroplasts appear to be involved in blue light photoreception during blue light-dependent stomatal opening and phototropic bending. The guard cell chloroplast has been studied in detail but the coleoptile chloroplast is poorly understood. The present study was aimed at the characterization of the corn coleoptile chloroplast, and its comparison with mesophyll and guard cell chloroplasts. Coleoptile chloroplasts operated the xanthophyll cycle, and their zeaxanthin content tracked incident rates of solar radiation throughout the day. Zeaxanthin formation was very sensitive to low incident fluence rates, and saturated at around 800-1000 μmol m(-2) s(-1). Zeaxanthin formation in corn mesophyll chloroplasts was insensitive to low fluence rates and saturated at around 1800 μmol m(-2) s(-1). Quenching rates of chlorophyll a fluorescence transients from coleoptile chloroplasts induced by saturating fluence rates of actinic red light increased as a function of zeaxanthin content. This implies that zeaxanthin plays a photoprotective role in the coleoptile chloroplast. Addition of low fluence rates of blue light to saturating red light also increased quenching rates in a zeaxanthin-dependent fashion. This blue light response of the coleoptile chloroplast is analogous to that of the guard cell chloroplast, and implicates these organelles in the sensory transduction of blue light. On a chlorophyll basis, coleoptile chloroplasts had high rates of photosynthetic oxygen evolution and low rates of photosynthetic carbon fixation, as compared with mesophyll chloroplasts. In contrast with the uniform chloroplast distribution in the leaf, coleoptile chloroplasts were predominately found in the outer cell layers of the coleoptile cortex, and had large starch grains and a moderate amount of stacked grana and stroma lamellae. Several key properties of the coleoptile chloroplast were different from those of mesophyll chloroplasts and resembled those of guard cell chloroplasts. We propose that the common properties of guard cell and coleoptile chloroplasts define a functional pattern characteristic of chloroplasts specialized in photosensory transduction.

Prevention of chymopapain anaphylaxis by screening chemonucleolysis candidates with cutaneous chymopapain testing

With chymopapain at a concentration of 10 mg/ml, the authors skin tested 540 chemonucleolysis candidates; six were positive, and 534 were negative. None of the positive patients received therapeutic injections of chymopapain. There were no instances of unequivocal anaphylaxis to chymopapain in the patients with negative skin tests treated with chymopapain. When this 0% incidence of systemic reactions in skin test negative patients is compared with the historical rate of 1%, this difference is statistically significant (p less than 0.05). Restriction of chymopapain treatment to patients with negative prick tests can reduce the incidence of systemic reactions.

Long-term studies in prevention of food allergy: patterns of IgG anti-cow's milk antibody responses

Over the past 7 years we have enrolled several hundred families in a study of the prophylaxis of atopic allergy. Initially, control and study patients were at different institutions, but more recently a true double-blind random assignment to control or study group has been instituted. Nevertheless, all of the infants from these highly atopic families can be utilized to obtain the data reported; that is, the rate of change of IgE levels, the appearance of food sensitization (food-specific IgE), the signs and symptoms of atopic allergy diseases and the changes in cow's milk-specific IgG antibody during the first 2 years of life. Some aspects of the first three of these parameters have been presented in the eight references to this paper, but only preliminary data on the use of IgG anti-cow's milk antibody as a measure of compliance has been available. In this paper an analysis is presented of the various patterns of IgG antibody levels in the first 60 infants of the over 200 who have been studied to date. Both the age of onset and the subsequent changes in the foregoing immunologic measurements provide fundamental data with which to measure the success rate of any prophylactic or therapeutic regimen and may improve our capacity to predict the future course of infants and children with a strong familial tendency to allergy.

Prevention of chymopapain anaphylaxis by screening chemonucleolysis candidates with cutaneous chymopapain testing. A preliminary report

The risk of anaphylaxis in candidates for chemonucleolysis for herniated lumbar discs is approximately 1%. An investigation was designed to eliminate or reduce the incidence of chymopapain anaphylaxis. The procedure was to restrict chemonucleolysis to patients who are prick test-negative to chymopapain at a concentration of 10 mg/ml. The authors skin-tested 292 chemonucleolysis candidates; five were positive and 287 were negative. None of the positive patients were injected with chymopapain. There were no instances of unequivocal chymopapain anaphylaxis in the skin test-negative group. This 0% incidence of anaphylaxis in skin test-negative patients was compared with a population estimate of 1%, based on historical data. The resulting value of p = 0.08 value fell short of the conventional level of significance of 0.05. The p value will reach 0.05 when the series of skin test-negative patients without anaphylaxis reaches 360. It is important that this information is readily available to physicians concerned about anaphylactic reactions to chymopapain.

Longitudinal effects of pregnancy on the pharmacokinetics of theophylline

The effects of pregnancy on the disposition of theophylline were assessed in 10 patients throughout pregnancy and post-partum. The clearance relative to total theophylline concentrations was only slightly affected during the first two trimesters (2.61 +/- 0.63 l/h and 2.85 +/- 1.05 l/h), while a statistically significant reduction was evident late in pregnancy (2.05 +/- 0.49 l/h). Post-partum clearance values (2.16 +/- 2.81 l/h) suggest an ongoing suppression relative to pre-pregnancy levels. A similar pattern was evident with clearance values based on free theophylline plasma concentrations (p = 0.12). Absolute volume of distribution increased in concert with gestation, suggesting that theophylline partitions into the enlarged tissue spaces. In addition, theophylline binding to plasma proteins decreased, albeit insignificantly, during the second (fraction bound = 29%) and third (32%) trimesters compared to post-partum values (41%). Increases in half-life during the third trimester (13.00 +/- 2.31 h vs 9.53 +/- 3.53 h post-partum) were highly significant. This change reflects the net effect of reduced clearance and increased distribution. Breast feeding had no effect on the disposition of theophylline, although the transfer of this compound into breast milk was confirmed.