Exogenous estrogen in systemic lupus erythematosus: oral contraceptives and hormone replacement therapy

Sex difference in human diseases: mechanistic insights and clinical implications

Sex characteristics exhibit significant disparities in various human diseases, including prevalent cardiovascular diseases, cancers, metabolic disorders, autoimmune diseases, and neurodegenerative diseases. Risk profiles and pathological manifestations of these diseases exhibit notable variations between sexes. The underlying reasons for these sex disparities encompass multifactorial elements, such as physiology, genetics, and environment. Recent studies have shown that human body systems demonstrate sex-specific gene expression during critical developmental stages and gene editing processes. These genes, differentially expressed based on different sex, may be regulated by androgen or estrogen-responsive elements, thereby influencing the incidence and presentation of cardiovascular, oncological, metabolic, immune, and neurological diseases across sexes. However, despite the existence of sex differences in patients with human diseases, treatment guidelines predominantly rely on male data due to the underrepresentation of women in clinical trials. At present, there exists a substantial knowledge gap concerning sex-specific mechanisms and clinical treatments for diverse diseases. Therefore, this review aims to elucidate the advances of sex differences on human diseases by examining epidemiological factors, pathogenesis, and innovative progress of clinical treatments in accordance with the distinctive risk characteristics of each disease and provide a new theoretical and practical basis for further optimizing individualized treatment and improving patient prognosis.

Sex hormones affect the pathogenesis and clinical characteristics of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) affects women more frequently than men, similar to the female predilection for other autoimmune diseases. Moreover, male patients with SLE exhibit different clinical features than female patients. Sex-associated differences in SLE required special considerations for disease management such as during pregnancy or hormone replacement therapy (HRT). Sex hormones, namely, estrogen and testosterone, are known to affect immune responses and autoimmunity. While estrogen and progesterone promote type I immune response, and testosterone enhances T-helper 1 response. Sex hormones also influence Toll-like receptor pathways, and estrogen receptor signaling is involved in the activation and tolerance of immune cells. Further, the clinical features of SLE vary according to hormonal changes in female patients. Alterations in sex hormones during pregnancy can alter the disease activity of SLE, which is associated with pregnancy outcomes. Additionally, HRT may change SLE status. Sex hormones affect the pathogenesis, clinical features, and management of SLE; thus, understanding the occurrence and exacerbation of disease caused by sex hormones is necessary to improve its management.

Reproductive health in women with systemic lupus erythematosus compared to population controls

OBJECTIVE

To study the reproductive health history in women with systemic lupus erythematosus (SLE) compared to population controls.

METHODS

A total of 206 female SLE patients were interviewed regarding demographic and disease data, menstruation, use of contraception and hormone replacement therapy (HRT), infertility, and pregnancies. The control group consisted of 1037 women from the general population of similar age and socioeconomic status living in the same region.

RESULTS

In SLE women compared to population controls, mean age at menarche (13.3 vs. 13.2 years) and frequency of infertility (16% vs. 16%) were similar but menopause occurred earlier (44.9 vs. 46.8 years, p = 0.01). Current use of oral contraceptives (OCs) was less common than in controls [18% vs. 28%, odds ratio (OR) 0.55, 95% CI 0.3-1.0] while previous use of progesterone-containing intrauterine devices (IUDs) was more common (13% vs. 5%, OR 3.2, 95% CI 1.9-5.4). Current use of HRT was similar (22% vs. 21%) but SLE patients had started the use earlier (43.2 vs. 47.1 years, p = 0.003). Mean number of pregnancies was lower in SLE patients compared to controls (2.3 vs. 2.5, p = 0.046) and in lupus nephritis patients compared to SLE patients without nephritis (1.9 vs. 2.5, p = 0.01). No difference was found in the occurrence of spontaneous and induced abortions compared to controls, but pregnancy-associated complications were more common in SLE women.

CONCLUSION

When compared to population controls women with SLE are normally fertile, use less OCs and more IUDs, have earlier menopause and use HRT as frequently. Family size is reduced, especially in lupus nephritis patients, and pregnancy-associated complications are more common.

[Estrogen use in systemic lupus erythematosus]

The role of exogenous estrogen in the initiation and maintenance of human systemic lupus erythematosus (SLE) remains very controversial. To review the current literature of the safety of using exogenous estrogens in patients with SLE, a Medline search for articles published between 1970 et 2004 regarding this relationship was performed. Although cohort studies suggest an increase in the incidence of SLE with both oral contraceptives and hormone replacement therapy, recent retrospective studies suggest that the risk of flares is not increased with hormone replacement therapy. Large prospective double blind placebo controlled studies inclusive of all ethnic groups such as the Safety of Estrogen in Lupus Erythematosus National Assessment (SELENA) trial had to provide the basis for definitive recommendations but it had been interrupted after WHI study results.

Anticardiolipin antibodies during hormone replacement therapy in healthy postmenopausal women

OBJECTIVE

The aim of the study was to investigate IgG and IgM anticardiolipin (aCL) antibodies in the course of hormone replacement therapy (HRT).

SUBJECTS AND METHODS

Thirty clinically healthy postmenopausal women with no history of previous thrombotic events or autoimmune disease were divided in two groups: control group (n = 12, mean age 52.9 +/- 4.5 years, and 6.2 +/- 3.6 years duration of amenorrhea) and a second group (n = 18, mean age 53.6 +/- 3.5 years, and 5.7+/- 4.5 years of amenorrhea) who were allocated to HRT, containing 2 mg 17-beta estradiol plus 1mg norethisterone acetate daily for 6 months. ACL antibodies of IgG and IgM isotype were assessed using ELISA and the Kupperman menopausal index (KI) was calculated at baseline and after 3 and 6 months of treatment.

RESULTS

HRT had a beneficial effect on climacteric symptoms, evaluated by KI (baseline versus 3rd month and 3rd month versus 6th month, P < 0.001 ). The KI did not change in the control group. The values of IgG at the three studied periods did not change significantly and were 14.1 +/- 4.2, 13.1 +/- 4.9 and 13.4 +/- 3.7 in the HRT group and 12.7 +/- 3.1, 13.7 +/-1.8 and 13.1 +/- 3.8 GPL, respectively, in the control group. IgM aCL antibodies increased during HRT and were as follows: 7.7 +/- 4.8 at baseline, 12.9 +/- 5.6 at 3rd month and 9.3 +/- 3.2 MPL at 6th month. In the control group, IgM were 8.0 +/- 2.8; 7.9 +/- 2.3 and 7.1 +/- 2.3 MPL, respectively. The differences between the two groups were significant at the third and the 6th month (P < 0.01 and P < 0.05 ).

CONCLUSION

These data suggest that HRT is associated with elevation of IgM ACA in healthy postmenopausal women. As IgG aACA are considered more pathogenic, it seems unlikely that the early prothrombogenic effects of HRT can be assigned to ACA.

The effect of 1-year transdermal estrogen replacement therapy on bone mineral density and biochemical markers of bone turnover in osteopenic postmenopausal systemic lupus erythematosus patients: a randomized, double-blind, placebo-controlled trial

We studied the effect of 1-year transdermal estrogen replacement therapy (ERT) on bone mineral density (BMD) and biochemical markers of bone turnover in osteopenic postmenopausal systemic lupus erythematosus (SLE) patients in a randomized, double-blind, placebo-controlled trial. SLE patients were randomly allocated to treatment (estradiol; 50 microg transdermal 17beta-estradiol; n=15) or placebo ( n=17) group. Both groups received 5 mg continuous oral medroxyprogesterone acetate, 500 mg calcium and 400 IU vitamin D(3). L(1)-L(4) spine (LS), left femur and total hip BMD were measured at baseline and at 6 and 12 months. Serum osteocalcin (OC) and degradation products of C-terminal telopeptides of type-I collagen (CTx) levels were measured at baseline and 3, 6, 9, and 12 months. There was a significant difference in the percentage change of LS BMD at 6 months between the two groups (103.24+/-3.74% (estradiol group) vs 98.99+/-3.11% (placebo group); P<0.005). There was a significant decrease within the estradiol group in the CTx levels between baseline and all subsequent visits ( P<0.05). There was no significant difference in SLE disease activity index, Systemic Lupus International Collaborating Clinics/American College of Rheumatology (ACR) damage index and corticosteroid dose during the study period. Transdermal estradiol may prevent bone loss in postmenopausal SLE women at the lumbar spine and femur, with no increase in disease activity among postmenopausal SLE women receiving transdermal ERT. The high dropout rate (8/15) leads us to the conclusion that efficacy of HRT in a high-risk group such as SLE women can be attained only in a small number of patients, provided all inclusion/exclusion criteria are strictly adhered to.

Lupus et autres connectivites et vie hormonale

Among connective tissue diseases, systemic lupus erythematosus is the illness that is most concerned by hormonal life events. The sex ratio is 9/1, and symptoms begin mostly during the third decade, sometimes during birth pill contraception or during pregnancy. As soon as systemic lupus is under control of an efficient treatment, pregnancy is no longer contra-indicated. A medical multidisciplinary surveillance is required. Complicated pregnancy concerns mother and baby. Lupus flares are more frequent during the second and third trimesters as well as during the post-partum period. Usually the intensity is moderate. Severe flares concern patients with renal involvement, hypertension and renal insufficiency and are mostly seen in patients with unplanified pregnancy and yet with still active lupus. Foetal death occurs in 10-30% of the cases, depending on the lupus activity and severity (renal lupus). Prematurity remains an important cause of morbidity (30% of live births). Foetal deaths and prematurity are even more frequent if the patient has an antiphospholipid syndrome. Neonatal cutaneous lupus and auriculo-ventricular congenital heart block is infrequent (1% of SLE patients with anti-Ro/SSA antibodies). Among other connective tissue diseases, polymyositis has a very severe obstetrical prognosis for both mother and foetus. Among primary vasculitis, polyarteritis nodosa, as found during pregnancy, can herald a very bad prognosis.

Pathogenesis of systemic lupus erythematosus

The exact patho-aetiology of systemic lupus erythematosus (SLE) remains elusive. An extremely complicated and multifactorial interaction among various genetic and environmental factors is probably involved. Multiple genes contribute to disease susceptibility. The interaction of sex, hormonal milieu, and the hypothalamo-pituitary-adrenal axis modifies this susceptibility and the clinical expression of the disease. Defective immune regulatory mechanisms, such as the clearance of apoptotic cells and immune complexes, are important contributors to the development of SLE. The loss of immune tolerance, increased antigenic load, excess T cell help, defective B cell suppression, and the shifting of T helper 1 (Th1) to Th2 immune responses leads to B cell hyperactivity and the production of pathogenic autoantibodies. Finally, certain environmental factors are probably required to trigger the disease.

Sex differences in infection and sepsis

Sex and gender-based differences in responses to infection and sepsis are evident. Estrogens increase immune function, sometimes to the point of inducing autoimmune disease. Testosterone suppresses immune function, sometimes leading to a worsened outcome following traumatic injury. Therapies using sex hormones to improve outcomes after sepsis and hemorrhagic shock and to reduce exacerbations of autoimmune diseases are being studied. Differences in sex hormone levels may not tell the whole story. Studies of immune function in girls and boys before puberty may be helpful. Differences found early might indicate that factors other than estrogen and androgen levels are contributing. Variations in societal role acculturation and exposures that are gender based also may be involved. Clinicians must consider sex and gender when attempting to determine the risk of infection, sepsis, and immune dysfunction in populations. Clinical applications of sex and gender differences are just beginning to occur with the genesis of sex hormone-based treatments. The large-scale efficacy of such treatments has yet to be reported. Innovative strategies based on sex or gender differences in immune responses may soon be available and may lead to essential data for clinical decision making. The impact of sex and gender differences on long-term health outcomes remains to be seen.

Treatment of the antiphospholipid syndrome

Despite increasing knowledge of the immunology and pathophysiology of the antiphospholipid syndrome, treating this condition remains challenging. Because of a paucity of randomized controlled trials, many of the treatment recommendations are not evidence-based. Retrospective case series suggest that a high level of oral anticoagulation is needed to prevent recurrent thrombosis. The combination of heparin and low-dose aspirin is effective in significantly increasing the chances of a successful pregnancy in woman with recurrent pregnancy failure associated with antiphospholipid antibodies. Primary prevention with aspirin is justified in patients with antiphospholipid antibodies but without a prior history of thrombosis. Interesting and controversial issues in the treatment of the antiphospholipid syndrome include the use of less intensive anticoagulation or antiplatelet agents in some patient subsets, anticoagulation for certain nonstroke neurologic conditions, the role of other agents (hydroxychloroquine, antioxidants), and novel immunomodulatory strategies.