Interferon responses in maternal and fetal mice

High maternal expression of SIGLEC1 on monocytes as a surrogate marker of a type I interferon signature is a risk factor for the development of autoimmune congenital heart block

Objectives

Autoimmune congenital heart block (CHB) is associated with placental transcytosis of maternal autoantibodies directed against Ro/SS-A and La/SS-B. However, only about 2% of children born to mothers with the respective antibodies are affected, indicating that further risk factors exist, which are not yet fully understood. In this study, we investigated whether a maternal type I interferon (IFN) signature represents a risk factor for the development of CHB.

Methods

Blood samples, clinical data and serological parameters from 9 women with CHB pregnancies, 14 pregnant women with antibodies against Ro/SS-A but without a CHB complication and another 30 healthy pregnant women as controls were studied. SIGLEC1 expression was measured by flow cytometry and was correlated to plasma IFN-α levels measured by ELISA, and IFN-γ-induced protein 10 (IP-10) levels measured by Bio-Plex technique.

Results

Mothers of affected children had a significantly higher expression of SIGLEC1 (p=0.0034) and IFN-α (p=0.014), but not of IP-10 (p=0.14, all MWU) compared to mothers of unaffected children. SIGLEC1 and IFN-α expression were reduced by hydroxychloroquine and oral glucocorticoids.

Conclusions

High expression of SIGLEC1 in pregnant women with autoantibodies against Ro/SS-A indicates an enhanced risk for CHB development, and these women may benefit especially from IFN-α directed therapy, for example with hydroxychloroquine.

Antiviral therapy for hepatitis B infection during pregnancy and breastfeeding

It is estimated there are 350-400 million people worldwide chronically infected with HBV. Many of these are women and of reproductive age. As such, they may face therapeutic decisions regarding antiviral therapy and the implication this may have on future or current pregnancies. This article reviews the data of all antivirals licensed for use against hepatitis B infection regarding teratogenicity, carcinogenicity, clinical experience during pregnancy, placental transfer and excretion in breast milk.

Conception and pregnancy during interferon-alpha therapy for chronic hepatitis C

We report a case of a patient who became pregnant while on interferon-alpha therapy for chronic hepatitis C. To date, there have been 23 reported cases of interferon administration during pregnancy; only one was in a patient with hepatitis C. We report our case and review the literature regarding the effects of interferon on pregnancy.

Fetal serum interferon-alpha suggests viral infection as the aetiology of unexplained lateral cerebral ventriculomegaly

We assayed fetal serum interferon-alpha (IFNA), a cytokine produced by leukocytes as a response to viral infection, in a series of 59 consecutive cases of ventriculomegaly diagnosed in utero and in 89 controls. Results were correlated with other findings including karyotype, maternal-fetal screening for serum antibodies to specific infectious pathogens, viral cultures of amniotic fluid, and neuropathological examination or postnatal follow-up. Fetal serum IFNA assay was negative in the five ventriculomegalies associated with a genetic anomaly and positive in the three cases with documented cytomegalovirus infections. In addition, fetal serum IFNA was detected significantly more often in the cases of ventriculomegaly with unexplained pathogenesis (15/51, 29.4 per cent) than in controls (1/89, 1.1 per cent). Detection of IFNA suggestive of viral infection in fetuses with otherwise unexplained ventriculomegaly underscores the need for more extensive viral screening in such cases.

Concurrence of high levels of interferons alpha and beta in cord and maternal blood and simultaneous presence of interferon in trophoblast in an African population

A high concentration of interferon-alpha (IFN-alpha) (> 5 U/ml) in cord blood was used as the criterion for establishing our study group. In a collection from deliveries by 269 Kenyan women, 16 such cord samples with matching maternal blood and placental biopsies were identified. These 16 were studied in detail together with 23 randomly selected among those with low cord IFN-alpha levels. The levels of IFN- in retal blood correlated with levels in their mothers for both IFN-alpha and beta but not for IFN-gamma. IFN-alpha was furthermore demonstrated in villous and decidual trophoblast from 15 (94%) placentae from donors with high IFN-alpha in the cord blood but not in the placenta of any low IFN level donors. In contrast, IFN-beta was not demonstrated in any placenta. These observations suggest simultaneous IFN induction in the three compartments, transplacental IFN transport, or trophoblast production of IFN to both circulations. Looking for IFN inducers, we did serologic tests for nonspecific indicators of inflammation and for specific virus and protozoan infections, but these showed no relation to elevated IFN levels. Immunohistology also revealed no evidence of a number of placental infections. The cause of the high levels of IFN-alpha could still be infectious but remains unexplained and may be noninfectious.

Successful treatment of essential thrombocythaemia and recurrent abortion with alpha interferon

A 27-year-old woman with essential thrombocythaemia (ET) had three miscarriages. She was treated with alpha interferon which was continued after she became pregnant again. The platelet count remained well controlled and at term she delivered a healthy baby with normal blood counts. The case demonstrates the effectiveness of IFN in preventing recurrent miscarriage associated with ET and the safety of IFN with respect to fertility and fetal development.

Fetal plasma interferon gamma concentration in normal pregnancy

OBJECTIVE

Our purpose was to investigate changes with gestation in fetal plasma interferon gamma concentration.

STUDY DESIGN

A cross-sectional study at the Harris Birthright Research Centre for Fetal Medicine, London, was performed. Enzyme-linked immunoassay was used to measure plasma concentration in 54 fetal blood samples obtained by cordocentesis or cardiocentesis at 12 to 37 weeks' gestation.

RESULTS

The concentration of interferon gamma in fetal plasma decreased exponentially from a mean of 1.2 U/ml at 12 weeks' gestation to a mean of 0.5 U/ml at 37 weeks (r = 0.460, p < 0.001).

CONCLUSIONS

The presence of high levels of fetal interferon gamma in the first trimester suggests that it may play an important role in early fetal immunologic development. Furthermore, this study has established reference ranges for interferon gamma that may be of value in the prenatal diagnosis of congenital infection.

What roles have anti-interferon antibodies in physiology and pathology?

Until recently the generation of antibodies to interferons (IFNs) was considered an unlikely event, while it is now clear that natural interferons (except IFN-beta) are practically nonimmunogenic, although recombinant interferons give rise to antibodies in about 30% of patients with occasional clinical complications. By realizing that normal individuals display spontaneously traces of IFN autoantibodies, in this review it is suggested that (if immunotherapy has to succeed) new generations of recombinant proteins should be the least antigenic as possible.

Alpha interferon in human pregnancy

The concentration of interferon-alpha was measured by a specific two-site immunoradiometric assay in a variety of fluids and tissues collected during human pregnancy. Maternal blood and blood and tissues from non-pregnant adults contained little or no interferon-alpha. Fetal blood, fetal organs, placenta, membranes, amniotic fluid and decidua all contained significant and roughly equivalent amounts ranging from 1.1 to 10 u/ml (or per g of tissue). These findings demonstrate that the fetus and its immediate surroundings are permeated with interferon. It is suggested that this may play a role in regulation of the maternal-fetal graft relation.