Rate of pregnancy-related relapse in multiple sclerosis. Pregnancy in Multiple Sclerosis Group

The thyroid immunology of the postpartum period

Autoimmune thyroid disease (AITD) is suppressed during pregnancy and is exacerbated in the postpartum period. Studies indicate that new-onset AITD occurs in up to 10% of all women in the postpartum period and that up to 60% of Graves' patients in the reproductive years give a history of postpartum onset. Despite this extraordinary epidemiological evidence, the causes of these exacerbations are uncertain and have yet to be adequately investigated. Explaining these postpartum changes, therefore, remains hypothetical. Mechanisms invoked include the passage of fetal cells to the mother during pregnancy establishing maternal microchimerism, pregnancy-induced changes in the thyroid gland itself, and the role of prolactin as a consequence of breast-feeding. Once the disease onset or exacerbation, is established, then there have been considerable advances in our understanding of the immunopathology. Thyroid cell destruction (via apoptosis) or activation (via thyrotropin [TSH] receptor autoantibody induction) appear to be similar to nonpostpartum-related disease. The reasons for the transience in postpartum disease, particularly thyroiditis, is likely to be related to the induction of clonal suicide and the mechanisms for this phenomenon are beginning to be explored. While we have a number of clinical indicators that allow us to predict postpartum thyroid disease (such as autoantibody titers), at present, we have no treatment to prevent the disease. Furthermore, our predictions are not helpful in a high enough proportion of the population to warrant screening of all women before delivery. At this time, the best clinical approach is watchful waiting and postpartum thyroid function testing where suspected.

Gender differences in protection from EAE induced by oral tolerance with a peptide analogue of MBP-Ac1-11

Mechanisms that contribute to increased female susceptibility to multiple sclerosis can be studied in the murine model of experimental autoimmune encephalomyelitis (EAE). In this report, we compared oral tolerance induction in male and female B10.PL mice using fed myelin basic protein (MBP) Ac1-11 peptide or a high-affinity analogue, Ac1-11[4Y]. We found that fed Ac1-11[4Y] peptide, but not native Ac1-11, could limit cellular infiltration into the central nervous system (CNS) and protect male mice from EAE, an effect that was completely obviated by castration. In contrast, female mice could not be orally tolerized or protected from EAE with either peptide. Tolerance induction in males was reflected by the appearance of Ac1-11[4Y]-reactive splenocytes that produced a sharply increased ratio of transforming growth factor (TGF)-beta:interleukin (IL)-2 and induced bystander suppression. These data directly demonstrate gender differences in regulatory T cells, and support the concept that androgens are involved in governing oral tolerance to EAE.

Correlation between sex hormones and magnetic resonance imaging lesions in multiple sclerosis

OBJECTIVE

To determine if sex hormones play a role in the pathogenesis of multiple sclerosis (MS) by correlating serum estradiol and progesterone levels with gadolinium (Gd) enhancing lesions on magnetic resonance imaging (MRI) in MS.

METHODS

Thirty patients with MS were studied with Gd enhanced brain MRI and simultaneous serum estradiol and progesterone levels either during the early follicular, late follicular or luteal phases of their menstrual cycle. Correlation between hormone levels and number of Gd enhancing lesions was determined.

RESULTS

Patients with high estradiol and low progesterone levels had a significantly greater number of Gd enhancing lesions than those with low levels of both these hormones. Patients with a high estrogen to progesterone ratio had a significantly greater number of active MRI lesions than those with a low ratio.

CONCLUSION

Estradiol and progesterone may influence disease activity in MS. If further studies confirm these results, it may be possible to develop therapy by altering levels of these hormones.

Pregnancy and multiple sclerosis: a 2-year experience

OBJECTIVE

To present our experience with management of parturients with multiple sclerosis and to examine the role of intravenous immunoglobulin (IVIg) in the prevention of postpartum exacerbations of the disease.

METHODS

Fifteen patients with multiple sclerosis with a relapsing-remitting course were followed during pregnancy and 6 months postpartum. To prevent postpartum exacerbations, 14 of the patients had received IVIg after delivery.

RESULTS

None of the patients who received postpartum IVIg relapsed during the 6 months after delivery. None of the observed obstetric complications nor the operative deliveries could be related to the coexistence of multiple sclerosis.

CONCLUSION

Postpartum IVIg treatment is beneficial in preventing acute childbirth-associated exacerbations in patients with relapsing-remitting multiple sclerosis. Furthermore, this disease does not seem to increase obstetric complications.

The influence of oral contraceptives on the risk of multiple sclerosis

OBJECTIVE

To examine the risk of multiple sclerosis in users of combined oral contraceptives.

DESIGN

Cohort study conducted between 1968 and 1996 using diagnostic data supplied by general practitioners

SETTING

General practices throughout the United Kingdom.

POPULATION

Royal College of General Practitioners' Oral Contraception Study cohort of initially 46,000 women recruited during the late 1960s.

METHODS

Directly standardised incidence rates of multiple sclerosis were calculated for current, former and never-users of oral contraceptives using first ever cases of multiple sclerosis reported by the general practitioners. The standardisation variables were age, parity, social class and smoking history. Five-year survival rates in the different contraceptive groups were calculated using standard life table techniques.

RESULTS

One hundred and fourteen first ever cases of multiple sclerosis had been reported by November 1996 during 564,000 woman-years of observation. The incidence rate in both current and former users was not materially different to that in never-users. Although based on limited evidence there was no suggestion that the five-year survival was affected by a woman's use of combined oral contraceptives.

CONCLUSIONS

These findings do not suggest a greatly elevated risk of multiple sclerosis during, or after, use of combined oral contraceptives.

The maternal immune system in health and disease

Recent studies have clarified some characteristics of trophoblast and immune cells in the decidua and peripheral blood during pregnancy and the roles they play in the maternal immune system, and have added further evidence to the theory that maternal T helper cell type 1/2 cytokine balance shifts towards T helper cell type 2 dominance during pregnancy.