Oestrogen-induced systemic lupus erythematosus

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.

Hormonal milieu at time of B cell activation controls duration of autoantibody response

A strong gender bias is seen in many autoimmune diseases including systemic lupus erythematosus (SLE). To investigate the basis for the female preponderance in SLE, we have been studying BALB/c mice in which B cells express the R4A heavy chain of an anti-DNA antibody in association with an endogenous light chain repertoire (R4Atg mice). In unmanipulated mice, approximately 5% of B cells express the R4A transgene. R4Atg mice do not spontaneously develop elevated serum titers of anti-DNA antibodies. Administration of either estradiol (E2) or prolactin (Pr) results in escape from tolerance of autoreactive B cells, expressed as an increase in transgene-expressing B cells and elevated serum titers of anti-DNA antibodies. We previously demonstrated that autoreactive B cells maturing in an estrogenic milieu develop as marginal zone (MZ) B cells; when these same B cells mature in the presence of increased prolactin, they develop as follicular (Fo) B cells. To determine the long term consequence of this differential maturation of DNA-reactive B cells, we treated R4Atg BALB/c mice with E2 or Pr for 6 weeks until serum titers of anti-DNA antibody were high, at which time hormonal exposure was discontinued. In E2-treated mice, the anti-DNA titers remained high even 3 months after discontinuation of hormone exposure. Nascent B cells underwent normal tolerance induction, but existing autoreactive MZ B cells persisted and continued to secrete autoantibody. In contrast, Pr caused only a short-term increase in anti-DNA antibody titers. By 3 months after cessation of hormone treatment, serum anti-DNA antibody titers and B cell subsets were indistinguishable from those in placebo (P) treated mice. These findings suggest that autoantibody responses are sustained for variable lengths of time depending on the B cell subset producing the autoantibodies. This observation may be relevant to understanding the heterogeneous presentation of patients with SLE and to the design of therapies targeting specific B-cell populations in autoimmune disease.

Cigarette Smoking, Alcohol Consumption, and Risk of Systemic Lupus Erythematosus: A Case-control Study in a Japanese Population

Objective.

Cigarette smoking may be associated with increased risk of systemic lupus erythematosus (SLE), whereas the role of alcohol consumption is unknown. We examined the association between SLE risk and smoking or drinking.

Methods.

We investigated the relationship of smoking and drinking compared to SLE risk among 171 SLE cases and 492 healthy controls in female Japanese subjects. Unconditional logistic regression was used to compute OR and 95% CI, with adjustments for several covariates.

Results.

Compared with nonsmoking, current smoking was significantly associated with increased risk of SLE (OR 3.06, 95% CI 1.86–5.03). The higher the level of exposure to cigarette smoke, the higher the risk of SLE. Inhalation was also associated with increased SLE risk (OR 3.73, 95% CI 1.46–9.94 for moderate inhalation; OR 3.06, 95% CI 1.81–5.15 for deep inhalation). In contrast, light/moderate alcohol consumption had a protective effect on SLE risk (OR 0.38, 95% CI 0.19–0.76). As for beer, the risks for non-beer drinkers and beer drinkers were similar. This also applies to alcoholic beverages other than beer.

Conclusion.

Our results suggest that smoking was positively associated with increased SLE risk whereas light/moderate alcohol consumption was inversely associated with SLE risk, irrespective of the type of alcoholic beverage. Additional studies are warranted to confirm these findings.

Estrogen and autoimmune disease

Estrogenic hormones possess both immunostimulating and immunosuppressive properties. In systemic lupus erythematosus (SLE), pregnancy is associated with disease flares. In some situations, exogenous estrogen predisposes to development of new SLE, flares of preexisting SLE, and thromboses in susceptible individuals. In contrast, treatment with exogenous estrogen protects postmenopausal rheumatoid arthritis (RA) patients from active RA and osteoporosis. The search for estrogen-like compounds with anti-inflammatory properties may expand treatment options in RA.

The effects of hormone replacement therapy on autoimmune disease: rheumatoid arthritis and systemic lupus erythematosus

Autoimmune diseases are generally more common in women than men; however, there is no simple explanation for this. Sex hormones, especially estrogen (but also prolactin and testosterone), play important roles in these diseases. Estrogens are generally considered to enhance autoimmunity and have multiple effects on the immune system through various cell types and molecular pathways. There is much evidence supporting the role of estrogen in the pathogenesis of systemic lupus erythematosus (SLE): the disease occurs much more frequently in women, especially during the years of child-bearing potential, and commonly flares during pregnancy. The relationship between estrogen and the development of SLE is complex, however. Exogenous estrogens have been historically avoided in women with SLE due to the widely held view that they could activate disease and their use remains controversial. Current evidence from prospective trials suggests that there may be a small increased risk of mild/moderate flares in women with SLE taking hormone replacement therapy (HRT), but the risk of major flare does not appear to be increased. In rheumatoid arthritis, HRT does not appear to be associated with an increased risk of disease flare and may actually improve disease activity. In all individuals with autoimmune disease, the risk of venous thrombosis associated with oral HRT is an important factor that should also be considered.

Hormonal regulation of B-cell function and systemic lupus erythematosus

The prevalence of systemic lupus erythematosus (SLE) is far higher in females than in males and numerous investigations to understand this gender bias have been performed, which propose as casual actors genetic predispositions and sex hormones effects. We will describe in this review how the sex hormones estrogen and prolactin influence B cell maturation and selection, permitting B cells to mature to immunocompetence in a mouse model of lupus. Finally, we will discuss the relevance and implications of these results for human disease.

Menopause hormonal therapy in women with systemic lupus erythematosus

OBJECTIVE

To evaluate the effects of menopause hormonal therapy on disease activity in women with systemic lupus erythematosus (SLE).

METHODS

We conducted a double-blind, randomized clinical trial involving 106 women with SLE who were in the menopausal transition or in early or late postmenopause. Patients received a continuous-sequential estrogen-progestogen regimen (n = 52) or placebo (n = 54). Disease activity was assessed at baseline and at 1, 2, 3, 6, 9, 12, 15, 18, 21, and 24 months, according to the SLE Disease Activity Index (SLEDAI). The primary outcome measure was global disease activity, estimated by measuring the area under the SLEDAI curve. Secondary outcome measures included maximum SLEDAI score, change in SLEDAI score, incidence of lupus flares, median time to flare, medication use, and adverse events. Results were studied using intent-to-treat analysis.

RESULTS

At baseline, demographic and disease characteristics were similar in both groups. Mean +/- SD SLEDAI scores were 3.5 +/- 3.3 and 3.1 +/- 3.4 in the menopause hormonal therapy and placebo groups, respectively (P = 0.57). Disease activity remained mild and stable in both groups throughout the trial. There were no significant differences between the groups in global or maximum disease activity, incidence or probability of flares, or medication use. Median time to flare was 3 months in both groups. Thromboses occurred in 3 patients who received menopause hormonal therapy and in 1 patient who received placebo. One patient in each group died during the trial due to sepsis.

CONCLUSION

Menopause hormonal therapy did not alter disease activity during 2 years of treatment. However, an apparently increased risk of thrombosis seems to be a real threat in women with SLE who receive menopausal hormone therapy.

Sex hormones and SLE: influencing the fate of autoreactive B cells

The prevalence of systemic lupus erythematosus (SLE) is far higher in females than in males and numerous investigations to understand this gender bias have been conducted. While it is plausible that some sex-linked genes may contribute to the genetic predisposition for the disease, other likely culprits are the sex hormones estrogen and prolactin. In this chapter we review studies that have addressed the influence of sex hormones in SLE activity and discuss the recent data established in a BALB/c mouse transgenic for the heavy chain of an anti-DNA antibody. These mice are prone to develop lupus following exposure to exogenous sex hormones. We describe how estrogen and prolactin influence B cell maturation and selection, permitting B cells to mature to immunocompetence. Finally, we discuss the relevance and implications of these data for human disease.

A trial of contraceptive methods in women with systemic lupus erythematosus

BACKGROUND

The effects of estrogen-containing contraceptives on disease activity in women with systemic lupus erythematosus have not been determined.

METHODS

We conducted a single-blind clinical trial involving 162 women with systemic lupus erythematosus who were randomly assigned to combined oral contraceptives, a progestin-only pill, or a copper intrauterine device (IUD). Disease activity was assessed at 0, 1, 2, 3, 6, 9, and 12 months according to the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). The primary outcome was global disease activity, which we estimated by measuring the area under the SLEDAI curve. Secondary outcomes included the maximum SLEDAI score, change in SLEDAI score, incidence of lupus flares, median time to first flare, systemic lupus erythematosus treatment, and adverse events. The results were analyzed by the intention-to-treat method.

RESULTS

At baseline, all demographic features and disease characteristics were similar in the three groups. The mean (+/-SD) SLEDAI score was 6.1+/-5.6 in the group assigned to combined oral contraceptives, 6.4+/-4.6 in the group assigned to the progestin-only pill, and 5.0+/-5.3 in the group assigned to the IUD (54 patients in each group) (P=0.36). Disease activity remained mild and stable in all groups throughout the trial. There were no significant differences among the groups during the trial in global or maximum disease activity, incidence or probability of flares, or medication use. The median time to the first flare was three months in all groups. Thromboses occurred in four patients (two in each of the two groups receiving hormones), and severe infections were more frequent in the IUD group. One patient receiving combined oral contraceptives died from amoxicillin-related severe neutropenia.

CONCLUSIONS

Global disease activity, maximum SLEDAI score, incidence of flares, time to first flare, and incidence of adverse events were similar among women with systemic lupus erythematosus, irrespective of the type of contraceptive they were using.

Estrogen as an immunomodulator

Estrogen's role in the sex differences observed in autoimmune diseases such as systemic lupus, multiple sclerosis, and rheumatoid arthritis have remained unclear. Complicating the understanding of the immunomodulatory effects of estrogen are (1) the effects of estrogen on multiple components of the immune response; (2) its varied effects on different systems in which it appears pro-autoimmune, as in murine lupus, or anti-inflammatory, as in EAE; and (3) its effects on other hormones which are potentially immunomodulatory. Recent reports have shed light on the role of estrogen in the modulation of lymphocyte survival and expansion and in the elaboration of Th1 versus Th2 cytokines and on the mechanisms by which estrogen can activate via multiple signaling and genomic pathways in immune cells.

Disease activity during the premenopausal and postmenopausal periods in women with systemic lupus erythematosus

PURPOSE

Cyclophosphamide-induced ovarian failure has been reported to be protective against flares of systemic lupus erythematosus (SLE). We studied whether patients with SLE experience a decrease in disease activity after natural menopause.

SUBJECTS AND METHODS

We studied 30 SLE patients with natural menopause who had been observed at least 2 years before and after menopause and who did not receive hormone replacement therapy or danazol. Menopause was defined as the date of the last self-reported menstrual period. Disease activity was assessed retrospectively by medical chart review using standard measures (the SLE disease activity index) during the immediate premenopausal and postmenopausal periods, and 2 (n = 30 patients), 3 (n = 19), and 4 (n = 13) years before and after menopause. We also compared the use of health services and medications.

RESULTS

Patients were studied for a mean (+/- SD) of 6.4 +/- 1.7 years (premenopausal, 3.3 +/- 0.9 years; postmenopausal, 3.2 +/- 0.9 years). During the premenopausal periods, the mean disease activity score was 2.3 +/- 2.3 (range, 0 to 9 on a 0 to 105 scale), compared with 2.3 +/- 2.9 (range, 0 to 12; P = 0.37) after menopause. The maximum disease activity score was somewhat greater in the premenopausal period (7.9 +/- 6.0 [range, 0 to 22] vs. 5.8 +/- 5.1 [range, 0 to 22]; P = 0.04). The incidence rates of flares (0.56 per year vs. 0.43 per year, P = 0.20) and severe flares (0.17 per year vs. 0.12 per year, P = 0.33) were similar in the premenopausal and postmenopausal periods. Differences in disease activity scores (mean and maximum) and the number of visits to a rheumatologist's office were only significant when the fourth year before menopause was compared with the fourth year after menopause.

CONCLUSIONS

Disease activity is mild during the premenopausal and postmenopausal periods in women with SLE. A modest decrease, especially in the maximum disease activity, is seen after natural menopause.

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

The role of exogenous estrogen in the initiation and maintenance of human SLE remains very controversial. 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 flare is not increased with hormone replacement therapy. However, exogenous estrogen does increase hypercoagulability, an issue in SLE patients with antiphospholipid antibodies. The prospective SELENA study will ultimately address whether exogenous estrogen increases severe flares in SLE.

Use of exogenous estrogens in systemic lupus erythematosus

OBJECTIVE

To review the current literature on the safety of using exogenous estrogens in patients with systemic lupus erythematosus (SLE).

METHOD

A MEDLINE search for articles published between 1970 and 2000 regarding the relationship between estrogens and SLE was performed. Emphasis was put on human studies, treatment trials, and epidemiologic surveys.

RESULTS

The use of exogenous estrogens in healthy women increases the risk of SLE development. For patients with established SLE, a hypoestrogenemic state appears to be protective against severe flares, whereas exogenous estrogen administration or hyperestrogenemia induced by hormonal manipulation may exacerbate the disease in certain individuals. Both the use of oral contraceptives and the use of hormonal replacement therapy (HRT) increase the chance of venous thromboembolism. The presence of antiphospholipid antibodies may aggravate the risk of thrombosis in SLE. In retrospective studies, HRT appears to be well tolerated in postmenopausal SLE patients.

CONCLUSIONS

There are no prospective data that show a deleterious effect of exogenous estrogens on disease activity in human SLE. Oral contraceptives may be considered for patients with SLE in the absence of active nephritis or antiphospholipid antibodies. The slight increase in venous thromboembolic risk should not be the chief deterrent to the use of HRT in postmenopausal SLE patients, considering its various health benefits.

Osteopenia in young hypogonadal women with systemic lupus erythematosus receiving chronic steroid therapy: a randomized controlled trial comparing calcitriol and hormonal replacement therapy

OBJECTIVE

To evaluate the efficacy of calcitriol and hormonal replacement therapy (HRT) in the treatment of steroid-induced osteoporosis in hypogonadal women.

METHODS

We studied 28 young patients (aged 37 +/- 6 yr) with systemic lupus erythematosus (SLE) on chronic steroid therapy for 130 +/- 22 months and requiring more than 10 mg/day prednisone. They were amenorrhoeic for more than 2 yr with proven ovarian failure. All had osteopenia with a T score at L2-4 of less than -1. They were randomized to receive HRT (conjugated oestrogen 0.625 mg daily from day 1 to day 21 plus medroxyprogesterone acetate 5 mg daily days 10-21) or calcitriol 0.5 microg daily. All received calcium carbonate 1 g/day.

RESULTS

There were no differences in the baseline demographic, bone mineral density (BMD) and biochemical data between the two groups. Lumbar spine BMD increased by 2.0 +/- 0.4% after 2 yr with HRT (P<0.05), but reduced by 1.74 +/- 0.4% (P<0.05) with calcitriol treatment. No change was seen at the distal one-third radius with HRT treatment but significant bone loss (2.3 +/- 1.4%, P<0.02) was observed with calcitriol therapy. BMD at the hip did not change in both groups. Comparing both treatment groups, significant differences in the BMD at the spine (P<0.03) and radius (P<0.05) were seen at the end of 2 yr. The changes in urinary n-telopeptide excretion but not serum osteocalcin at 6 months and 12 months were inversely correlated with the changes in lumbar spine BMD at 24 months. HRT did not cause an adverse effect on SLE disease activity.

CONCLUSION

HRT but not calcitriol could prevent bone loss in young hypogonadal women on chronic steroid therapy.

Ovarian failure and flares of systemic lupus erythematosus

OBJECTIVE

To study the effects of ovarian failure on disease flares in systemic lupus erythematosus (SLE).

METHODS

Fifty-four female premenopausal SLE patients who were under the age of 45 years and treated with continuous oral cyclophosphamide (CYC) for no more than 12 months were studied. All patients had been followed up for >5 years following CYC treatment. Demographic characteristics, clinical and serologic profiles, and information concerning disease flares were recorded. Comparison of the number of severe and mild/moderate flares during the first 5 years after CYC treatment was made between patients who developed CYC-induced ovarian failure and those who did not.

RESULTS

Fourteen SLE patients had documented ovarian failure with hypoestrogenemia within 2 years after CYC treatment. Compared with the menstruating group of patients, those who developed ovarian failure were significantly older at the time of CYC therapy (mean 37.9 versus 25.5 years; P < 0.001), but otherwise no significant differences in organ manifestations and autoantibody profiles between the 2 groups were observed. Both the ovarian failure group and menstruating group of patients had similar SLE Disease Activity Index scores at the time of CYC treatment (mean 15.6 versus 17.7; P = 0.16), and had comparable treatment durations (mean 8.2 versus 7.8 months; P = 0.68) and cumulative doses of CYC (mean 20.4 versus 17.9 grams; P = 0.34). Flares of SLE were uncommon during the first year following CYC administration. However, during the 5-year followup period, patients who developed CYC-induced ovarian failure had significantly fewer severe flares (mean 0.014 versus 0.075 flares/patient-year; P = 0.01) and smaller total number of flares (mean 0.128 versus 0.250 flares/patient-year; P = 0.03) when compared with those who were still menstruating.

CONCLUSION

This study provides an important clinical observation to support the notion that ovarian failure with hypoestrogenemia is protective against lupus flares and emphasizes the importance of estrogen status in the determination of disease activity in SLE.

Safety of hormone replacement therapy (HRT) in systemic lupus erythematosus (SLE)

Despite its obvious benefits, many physicians are reluctant to prescribe HRT to patients with SLE. We have performed a retrospective study in 60 postmenopausal women with SLE including 30 HRT users and 30 never users. The patients were studied for 12 months after the initiation of HRT. The two groups were well matched for disease characteristics. The HRT users experienced significant improvements in general well being, libido and depression. There was no significant difference in any other parameter measured. There was no increase in the number of thrombo-embolic events in the user group despite 7 patients having a positive thrombophilia screen. In conclusion, in stable postmenopausal SLE HRT appears well tolerated and safe.

Loss of trabecular bone mineral density in systemic lupus erythematosus

OBJECTIVE

To evaluate trabecular bone mineral density (BMD) in young ambulatory female patients with systemic lupus erythematosus (SLE).

METHODS

Bone mineral density (gm/cm2) at the lumbar vertebrae (L1-L4) and at the left femur (neck, trochanter, intertrochanter, and Ward's triangle) was measured by dual x-ray absorptiometry in 46 SLE patients (mean age 31 years, mean disease duration 76 months) and in 108 healthy female controls (mean age 32 years). Twenty-two of the SLE patients were receiving corticosteroids (CS) at the time of the study.

RESULTS

Lumbar BMD in the SLE patients was less severely reduced than was BMD at the femoral sites, but the SLE group was closer to the lumbar fracture threshold of 0.812 gm/cm2 than was the control group (P = 0.0009). There were no significant differences between the SLE patients currently being treated with corticosteroids and those who were not (P > 0.3). BMD at Ward's triangle and at the femoral neck was not significantly reduced in the SLE patients. Total femoral BMD had a sensitivity of 76% and specificity of 62% in differentiating the SLE group from the controls. The positive predictive value was 61% and the negative predictive value was 89%. The prevalence of osteopenia in the SLE patients was 25%.

CONCLUSION

SLE causes significant trabecular bone loss, which is not due to corticosteroid therapy.

Anti-estrogen antibodies in systemic lupus erythematosus: a quantitative evaluation of serum levels

We measured the beta-estradiol binding capacity of serum gamma-globulins in four subject groups; 1) normal men, 2) normal women who had never taken oral contraceptives, 3) normal women who had a history of oral contraceptive use and, 4) patients with systemic lupus erythematosus (SLE). We used dextran-coated charcoal to strip endogenous estradiol from serum proteins, added 3H-estradiol, and measured its association with proteins in various electrophoretic fractions following zone separation on agarose gels. Most of the bound radioactivity was present in the albumin, beta and gamma-globulin fractions. Binding to gamma-globulins was elevated in SLE patients, and normal controls who had taken oral contraceptives, as opposed to other controls (p less than 0.005). Gamma-region radioactivity could be removed by protein-G adsorption prior to zone electrophoresis. Isoelectric focusing revealed a pattern of tritiated-E2 binding consistent with polyclonal B-cell activation in all groups. There was no correlation between the extent of gamma-region binding and the total serum immunoglobulin level for any of the groups studied, nor was there a correlation between E2 binding and anti-DNA titers in the SLE group. The average anti-estradiol antibody concentrations in SLE sera (assuming equimolar binding) was 105 ng/ml (95% CL = 92-118), whereas their average anti-DNA antibody concentration was in the microgram/ml range. Thus, quantitatively, the level of anti-estradiol antibodies is at least an order of magnitude lower than the anti-DNA antibodies characteristic of this disease.

Restoration of the DNA binding activity of estrogen receptor in MRL-lpr/lpr mice by a polyamine biosynthesis inhibitor

Diverse data link estrogen influences to both the frequency and severity of systemic lupus erythematosus in humans and to murine lupus. A fundamental mechanism of action of estrogen involves the interaction of the hormone with its receptor protein, which is then transformed into the DNA binding form. We measured the concentration of uterine estrogen receptor and its DNA binding in normal BALB/c mice, lupus-prone MRL-lpr/lpr mice, and MRL-lpr/lpr mice that had been treated with 1% difluoromethylornithine (DFMO). Uterine estrogen receptor levels in 20-week-old mice from the 3 groups were not significantly different. In contrast, DNA binding activity was significantly higher in BALB/c mice (mean +/- SD 775 +/- 100 fmoles/mg of DNA) than in untreated MRL-lpr/lpr mice (80 +/- 16 fmoles/mg of DNA) (P less than 0.001). Treatment with 1% DFMO was associated with an increase in uterine estrogen receptor DNA binding (1,100 +/- 218 fmoles/mg of DNA) in MRL-lpr/lpr mice (P less than 0.001). Polyamine levels were 2-6-fold higher in the uterine tissues of untreated MRL-lpr/lpr mice compared with the BALB/c mice and were significantly reduced by DFMO treatment. Our results link uterine polyamine production to a dysfunction of the estrogen receptors in MRL-lpr/lpr mice. Reduction of the polyamine level by the irreversible inhibition of ornithine decarboxylase with DFMO restores estrogen receptor function.