Maternal reactivity to fetal alloantigens is related to newborn immune responses and subsequent allergic disease

BACKGROUND

Maternal allergy confers stronger allergy risk (than paternal allergy) suggesting that maternal patterns of immune response can directly influence immune development in offspring. Women prone to allergic immune responses to allergens may also have altered immune responses to other antigens including fetal antigens.

OBJECTIVE

This exploratory study examines relationships between maternal immune responses to fetal antigens and the subsequent risk of allergy.

METHODS

Mononuclear cells (MNC) were collected from 36 mother-infant pairs to compare maternal (and fetal) cellular immune responses to alloantigens (fetal, maternal or unrelated donor [URD]), and allergens in allergic (18 pairs) and non-allergic (18 pairs) mothers. Thirty children had documented allergic outcomes at 6 years of age.

RESULTS

In this population, allergic outcomes in the offspring were associated more strongly with materno-fetal immune interactions than with a maternal family history of allergy. Specifically, allergic disease at 6 years of age was associated with significantly higher maternal responses to fetal alloantigens (lymphoproliferation, P=0.008; IL-13, P=0.02 and IFN-gamma, P=0.015), whereas associations with maternal allergy did not reach significance (P=0.07). Fetal IFN-gamma alloantigen responses were significantly correlated with the degree of human lymphocyte antigen (HLA) mismatch (maternal HLA class II antibodies) (tau=0.3, P=0.03). The capacity of the fetus to produce IL-13 (tau=0.4, P=0.001) and IL-10 (tau=0.3, P=0.029) was directly related to the level of these cytokines produced by the mother in response to fetal antigens. Allergic mothers showed a non-significant trend for stronger lymphoproliferation to fetal alloantigens. The number of previous pregnancies (gravidity) was associated with stronger maternal responses to fetal alloantigens, as shown by lymphoproliferation (Kendall tau=0.3, P=0.04) and IFN-gamma (tau=0.3, P=0.04) synthesis, but did not affect fetal responses to the various stimuli.

CONCLUSIONS

Maternal responses to fetal antigens were related to fetal immune responses and subsequent allergy. This novel observation suggests that events at the materno-fetal interface have an important influence on early immune development and should be investigated further.

Maternal reactivity to fetal alloantigens is related to newborn immune responses and subsequent allergic disease

BACKGROUND

Maternal allergy confers stronger allergy risk (than paternal allergy) suggesting that maternal patterns of immune response can directly influence immune development in offspring. Women prone to allergic immune responses to allergens may also have altered immune responses to other antigens including fetal antigens.

OBJECTIVE

This exploratory study examines relationships between maternal immune responses to fetal antigens and the subsequent risk of allergy.

METHODS

Mononuclear cells (MNC) were collected from 36 mother-infant pairs to compare maternal (and fetal) cellular immune responses to alloantigens (fetal, maternal or unrelated donor [URD]), and allergens in allergic (18 pairs) and non-allergic (18 pairs) mothers. Thirty children had documented allergic outcomes at 6 years of age.

RESULTS

In this population, allergic outcomes in the offspring were associated more strongly with materno-fetal immune interactions than with a maternal family history of allergy. Specifically, allergic disease at 6 years of age was associated with significantly higher maternal responses to fetal alloantigens (lymphoproliferation, P=0.008; IL-13, P=0.02 and IFN-gamma, P=0.015), whereas associations with maternal allergy did not reach significance (P=0.07). Fetal IFN-gamma alloantigen responses were significantly correlated with the degree of human lymphocyte antigen (HLA) mismatch (maternal HLA class II antibodies) (tau=0.3, P=0.03). The capacity of the fetus to produce IL-13 (tau=0.4, P=0.001) and IL-10 (tau=0.3, P=0.029) was directly related to the level of these cytokines produced by the mother in response to fetal antigens. Allergic mothers showed a non-significant trend for stronger lymphoproliferation to fetal alloantigens. The number of previous pregnancies (gravidity) was associated with stronger maternal responses to fetal alloantigens, as shown by lymphoproliferation (Kendall tau=0.3, P=0.04) and IFN-gamma (tau=0.3, P=0.04) synthesis, but did not affect fetal responses to the various stimuli.

CONCLUSIONS

Maternal responses to fetal antigens were related to fetal immune responses and subsequent allergy. This novel observation suggests that events at the materno-fetal interface have an important influence on early immune development and should be investigated further.

The effect of supplementation with fish oil during pregnancy on breast milk immunoglobulin A, soluble CD14, cytokine levels and fatty acid composition

BACKGROUND

Breast milk contains many immunomodulatory factors (soluble CD14 (sCD14), IgA and cytokines) with the potential to influence infant immune development.

OBJECTIVE

To determine if changes in breast milk omega-3 polyunsaturated fatty acid (n-3 PUFA) composition as a result of maternal dietary fish oil supplementation during pregnancy can modify levels of these immunological parameters in breast milk.

METHOD

In a randomized controlled trial, 83 atopic women received either 4 g fish oil capsules (containing 3.7 g n-3 PUFA) (n = 40) or 4 g olive oil capsules (n = 43) from 20 weeks gestation until delivery. Breast milk was collected 3 days post-partum and fatty acids were analysed by gas liquid chromatography and IgA, sCD14 and cytokines (IL-5, IL-6, IL-10, TNF-alpha and IFN-gamma) were quantitated by ELISA or time resolved fluorescence (TRF).

RESULTS

Omega-3 docosahexaenoic acid (DHA; 22:6n-3) and eicosapentaenoic acid (EPA; 20:5n-3) levels were significantly higher (P < 0.001) in breast milk from women supplemented with fish oil (n = 33, DHA mean 1.15%, SD 0.47% and EPA mean 0.16%, SD 0.07%) than in samples from the control group (n = 40, DHA mean 0.50%, SD 0.17% and EPA mean 0.05%, SD 0.02%). Breast milk arachidonic acid (AA; 20:4n-6) levels were significantly lower (P = 0.045) in the fish oil group (mean 0.55%, SD 0.12%) compared with the control group (mean 0.61%, SD 0.14%). Breast milk IgA was positively correlated with DHA (P = 0.046) and 22:5n-3 (P = 0.003), but inversely correlated with linoleic acid (LA; 18:2n-6) (P=0.034). Levels of sCD14 were also positively correlated with 22:5n-3 (P=0.009). Cytokines involved in IgA synthesis (IL-10 and IL-6) were also significantly correlated with both IgA and n-3 PUFA levels, although there were no differences in the levels of breast milk IgA, sCD14 or cytokines between study groups.

CONCLUSION

Supplementation with fish oil during pregnancy significantly alters early post-partum breast milk fatty acid composition. omega-3 PUFA levels were positively associated with IgA and sCD14 levels, suggesting a relationship between fatty acid status and mucosal immune function.

Deficiency of natural anticoagulant proteins C, S, and antithrombin in portal vein thrombosis: a secondary phenomenon?

BACKGROUND

Hereditary deficiencies of natural anticoagulant proteins are implicated in the pathogenesis of portal vein thrombosis (PVT). Secondary deficiencies of these proteins have also been reported in PVT, making interpretation of concentrations difficult.

AIMS

To characterise the coagulation profiles in adult patients with PVT and to investigate the possible mechanisms of natural anticoagulant protein deficiency.

PATIENTS

Twenty nine adult patients with portal hypertension caused by PVT, and normal biochemical liver function tests.

METHODS

Routine coagulation profiles and concentrations of proteins C, S, and antithrombin were measured; where indicated, corresponding concentrations in parents were also measured. Synchronous peripheral and hepatic or splenic vein concentrations were compared in seven patients undergoing interventional procedures, as were peripheral concentrations before and after shunt surgery in three patients.

RESULTS

Deficiencies of one or more of the natural anticoagulant proteins occurred in 18 patients (62%), with six patients having combined deficiency of all three proteins. There were strong correlations between prothrombin and partial thromboplastin time ratios and concentrations of natural anticoagulant proteins. Family studies in nine cases of anticoagulant protein deficiency revealed possible hereditary deficiency in only three cases, and significantly lower concentrations of anticoagulant proteins in all PVT cases compared with parents. Levels of anticoagulant proteins tended to be lower in hepatic veins but higher in splenic veins compared with peripheral vein concentrations. Peripheral concentrations decreased after shunt surgery.

CONCLUSIONS

Deficiency of natural anticoagulant proteins is common in PVT and is probably a secondary phenomenon in most cases, occurring as part of a global disturbance of coagulation variables. The mechanism for this remains unclear but may result from a combination of reduced hepatic blood flow and portosystemic shunting itself.

Episodes of allied health outpatient care: an investigation of service delivery in acute public hospital settings

This paper describes 'episodes of allied health outpatient care' by linking related clinical allied health outpatient contacts. Episodes were tracked on 10095 patients in 46 public hospital outpatient services in eight hospitals over a 10-month period during 1996, as part of a Commonwealth Ambulatory Care Reform project. Fifty-one per cent of patients completed at least one 'episode of allied health outpatient care' during the period of the study. An episode theoretically comprised all those occasions of service provided to the one patient for the one condition in the one allied health outpatient service, using the one referral. There were difficulties in flagging the beginning and end of episodes, as services used specific ways of defining and recording episode characteristics. Describing allied health outpatient service usage by episode has implications for developing funding models that are appropriate to the core business of allied health services.

The Schiff base complex of yeast 5-aminolaevulinic acid dehydratase with laevulinic acid

The X-ray structure of the complex formed between yeast 5-aminolaevulinic acid dehydratase (ALAD) and the inhibitor laevulinic acid has been determined at 2.15 A resolution. The inhibitor binds by forming a Schiff base link with one of the two invariant lysines at the catalytic center: Lys263. It is known that this lysine forms a Schiff base link with substrate bound at the enzyme's so-called P-site. The carboxyl group of laevulinic acid makes hydrogen bonds with the side-chain-OH groups of Tyr329 and Ser290, as well as with the main-chain >NH group of Ser290. The aliphatic moiety of the inhibitor makes hydrophobic interactions with surrounding aromatic residues in the protein including Phe219, which resides in the flap covering the active site. Our analysis strongly suggests that the same interactions will be made by P-side substrate and also indicates that the substrate that binds at the enzyme's A-site will interact with the enzyme's zinc ion bound by three cysteines (133, 135, and 143). Inhibitor binding caused a substantial ordering of the active site flap (residues 217-235), which was largely invisible in the native electron density map and indicates that this highly conserved yet flexible region has a specific role in substrate binding during catalysis.

Do different fluorochrome labels give equivalent histomorphometric information?

Substances that bind calcium are given to determine where and how fast bone is forming. Several vital dyes are used (tetracycline, calcein, alizarin, xylenol), but it is not known whether the histomorphometric results they provide are equivalent. This work tests whether different fluorochrome labels give the same results when they are quantitatively measured. Twelve-week-old rats (n = 58) were divided into six groups and given double labels IP of calcein, tetracycline HCl, alizarin complexone, or xylenol using a 1-7-1 scheme. Two other groups received either calcein followed by tetracycline, or tetracycline followed by calcein. Our results show that (a) tetracycline hydrochloride leads to a significant underestimation of mineralizing surface when given as the second label, probably because of its weak fluorescence; (b) there were no differences among any of the non-tetracycline labels for any of the histomorphometric measurements; (c) there was no evidence of osteoblast suppression with any label; and (d) there was no evidence that tetracycline caused increased osteoblast resting periods.

Computer generated discharge summaries for a neonatal unit

Computer generated discharge summaries are gaining in popularity. A simple and flexible method for generating neonatal summaries using commercially available software is described.

Uptake of immunisations in low birthweight infants

The timing of immunisations for preterm infants is controversial. Because of the statement by the British Paediatric Association/Joint Committee on Vaccination and Immunisation Liaison group that immunisations should normally begin three months after the date of birth, the records of all infants born in 1984 and currently (June 1986) resident in the London Borough of Newham were studied to find out if this recommendation was being implemented. Subjects were divided into groups by birth weight and where possible by gestational age. Cumulative uptakes by age of any component of the first and third triple immunisations, and of the pertussis component, were plotted separately. Comparison of uptake of the first course showed a considerable initial delay for infants weighing less than 2000 g at birth compared with heavier babies, but by 18 months the coverage was almost identical. This difference was not evident for the third course. A similar delay was apparent when infants of 37 weeks' gestation or less were compared with babies born at full term, though recording of gestational age was incomplete. Final overall uptake was poor for all groups. Differences among groups in numbers consenting were not an important factor. Informing those responsible for giving the immunisations of these findings has stimulated their interest in improving practice by implementing the recommendations.

Haemorrhage into the anterior pituitary during pregnancy after induction of ovulation with clomiphene

A 34-year-old woman with secondary amenorrhoea and primary infertility became pregnant after treatment with clomiphene. She developed pre-eclampsia. Visual symptoms were experienced due to rapid enlargement of the anterior pituitary gland. The patient was delivered by Caesarean section. At subsequent craniotomy the patient was found to have haemorrhage into the pituitary gland, but histological examination of the pituitary tissue which was removed revealed no tumour tissue. One year after delivery the patient was still amenorrhoeic and had galactorrhoea with hyperprolactinaemia indicating that she probably had a small pituitary adenoma which was incompletely removed during neurosurgery.