Antinuclear factor and L.E. cells in pregnant women

Association between antinuclear antibody and female infertility: A meta-analysis

Autoimmunity is reported involving in reproductive failures, and antinuclear antibody (ANA) positivity has been regarded as a typical feature of autoimmunity. Published studies on the association of ANA with reproductive failures including infertility are controversial. The aim of this meta-analysis was to analyse whether the presence of ANA positivity increases the risk of infertility in women. We searched the PubMed and Embase databases for relevant literature without any restrictions prior to April 28, 2021. All analyses were performed using the RevMan 5.3 software. Twelve studies with 2734 participants, including 1482 patients with infertility, met the inclusion and exclusion criteria. The total positivity rate of ANA was 23.8% (353/1482) in all infertile patients and 8.5% (107/1252) in the control group. Infertile females had a significantly higher ANA positivity rate than the control group (odds ratio [OR] = 2.90, 95% confidence interval [CI]: 1.72-4.87, I2 = 65%, P < .0001). Several subgroup analyses were performed to reduce the heterogeneity. ANA positivity was associated with female infertility in studies either performed by indirect immunofluorescence (OR = 2.26, 95% CI:1.67-3.06, P < .00001) or by ELISA (OR = 10.76, 95% CI:1.82-63.64, P < .00001). ANA was significantly associated with increased risk of women infertility either after the definite exclusion of individuals with autoimmune diseases (AID) or without exclusion [(OR = 1.99, 95% CI:1.29-3.06, P = .002), (OR = 2.76, 95% CI:1.56-4.88, P = .0005), respectively]. This meta-analysis provides a comprehensive overview of the prevalence of antinuclear antibodies (ANA) in infertile women and suggests that ANA positivity increases the risk of infertility.

Antinuclear antibodies positivity is a risk factor of recurrent pregnancy loss: A meta-analysis

OBJECTIVE

Immunologic mechanisms have been proposed as part of the pathogenesis mechanisms involved in recurrent pregnancy loss (RPL). Presence of positive antinuclear antibodies (ANA) is regarded as a typical feature of autoimmunity. Many studies had tried to clarify the association of ANA with RPL, but the conclusions were controversial. The aim of this meta-analysis was to assess whether ANA was positively associated with increased RPL risk.

METHODS

We searched PubMed and Embase databases for relevant literatures on the association between ANA positivity and RPL. The odds ratios (OR) with 95% confidence intervals (95%CI) were pooled using meta-analysis, and either fixed-effect or random-effect model was used based on heterogeneity across the included studies.

RESULTS

Twenty-one studies with 5038 participants (including 2683 RPL patients and 2355 controls) met the inclusion criteria were included. The total positive rate of ANA was 22.0% (591/2683) in RPL group, and 8.3% (196/2355) in the control group. RPL patients had a significantly higher ANA positive rate than controls (OR = 2.97, 95%CI 1.91-4.64, P<0.00001; I² = 75%), and a significant association between positive ANA and unexplained RPL was also observed (OR = 3.27, 95%CI 2.01-5.31, P<0.00001; I² = 70%). ANA positivity was also significantly associated with increased risk of RPL in women without defined autoimmune diseases (OR = 2.23, 95%CI 1.40-3.55, P=0.0007). Subgroup analysis demonstrated low titers of ANA (1:40≤ANA≤1: 80) were not associated with RPL (OR = 2.44, 95%CI 0.42-14.06, P=0.32), while higher ANA titer (≥1:160) had a significant association with RPL (OR = 45.89, 95%CI 8.44-249.45, P<0.00001). A higher rate of homogenous pattern in RPL patients was observed (OR = 4.89, 95%CI 2.20-10.87, P<0.001), and no significant difference in speckled pattern or nucleolar pattern was found.

CONCLUSIONS

This study demonstrated that ANA positivity was positively associated with increased RPL risk. ANA positivity is an important risk factor for RPL which needed to be screened among women with RPL.

Prevalence of non-organ-specific autoantibodies in pregnant and non-pregnant healthy women

The prevalence of autoantibodies during pregnancy was studied. Sera from 568 women (203 pregnant and 365 non-pregnant) were tested for autoantibodies to double-stranded DNA, cardiolipin and extractable cellular antigens. Nineteen out of 203 pregnant women (9.4%) had at least one autoantibody against double-stranded DNA or cardiolipin, mainly of the IgM class. The non-pregnant control group had significantly higher incidence of autoantibodies (17.8%; chi 2 = 7.39, P < 0.01). Sixty-six out of 568 women had had spontaneous abortions in their past medical history, but there was no correlation between them and the presence of anticardiolipin antibodies. Two of the non-pregnant women had anti-Ro(SSA) antibodies. These findings suggest that (a) the prevalence of autoantibodies decreases during pregnancy; and (b) the presence of anticardiolipin antibodies in healthy pregnant women does not correlate with any pregnancy-related complications. However, our results indicated that autoimmunity is a rather common disorder in healthy women.

Antinuclear autoantibodies in healthy nonpregnant and pregnant women and their offspring

Antinuclear autoantibodies have previously been detected in sera of healthy women although less frequently than in sera of women with autoimmune disorders. The effect of pregnancy on antinuclear autoantibody production in healthy women is as yet debatable. We present four studies in which, by employing the ELISA method, we evaluated the presence of six antinuclear autoantibodies (anti-ds DNA, anti-ss DNA, anti-poly(I), anti-cardiolipin, anti-Sm, and anti-RNP) in the sera of more than 1,000 healthy pregnant and nonpregnant women, including 196 pairs of matched maternal and cord blood sera. In all four studies healthy pregnant women did not demonstrate significantly higher prevalence rates of various serum antinuclear autoantibodies as compared to healthy non-pregnant women. All detected autoantibodies were of the IgM isotype. In only one infant (born to a healthy seronegative mother) was an autoantibody (IgM anti-ss DNA) detected. This may indicate that in certain circumstances the fetus is capable of self-production of autoantibodies.

Antinuclear antibodies in sera of patients with recurrent pregnancy wastage

Four groups of women were studied to determine whether low-level antinuclear antibody titers are associated with a higher risk for pregnancy loss. Group A consisted of 30 patients with a history of unexplained fetal losses. Group B consisted of 30 women with "explained" fetal losses (e.g., uterine septum or luteal phase defect). Ages and number of losses were comparable between the women in groups A and B. Group C consisted of 61 healthy pregnant women. Group D involved 61 healthy nonpregnant women of reproductive age. In groups A and B, 40% and 53.3% of the respective patients had antinuclear antibody titers greater than or equal to 1:40. In groups C and D the frequencies of positive antinuclear antibody titers were 8.2% and 5.6%, respectively. This study demonstrates a high prevalence of low-titer antinuclear antibody-positive serum in patients with explained and unexplained pregnancy losses.

Antinuclear autoantibodies in sera of healthy pregnant women and their offspring

The presence of autoantibodies in the fetus has previously been investigated in the offspring of mothers with autoimmune diseases, but not in the offspring of healthy pregnant women. Employing the ELISA method, we examine four SLE-associated auto-antibodies (anti-dsDNA, anti-ssDNA, anti-poly(I), and anti-cardiolipin) in sera obtained from 196 healthy pregnant women and their offspring. All detected autoantibodies in maternal and blood cord sera were of the IgM isotype. Thirty-four maternal sera (17.3%) were positive for one or more tested autoantibodies: 16 (8.1%) for one autoantibody alone, 17 (8.6%) for two autoantibodies, and one (0.5%) for three autoantibodies; 1.5%, 5.6%, 9.6%, and 10.2% of the maternal sera were positive for autoantibodies against dsDNA, ssDNA, poly(I), and cardiolipin, respectively. In only one blood cord serum sample was an autoantibody (IgM anti-ssDNA) detected. This infant was born to a healthy seronegative mother. The finding that all offspring of IgM seropositive mothers are IgM seronegative is not surprising since maternal IgM autoantibodies do not cross the placenta. The finding of an IgM seropositive infant born to an IgM seronegative mother may indicate that the fetus is capable of self-production of autoantibodies.

The prevalence of autoantibodies in pregnant and nonpregnant women

The frequency of autoantibodies during pregnancy was studied. Sera from 136 women (84 pregnant and 52 nonpregnant) were tested for antibodies directed against nuclear antigens, smooth muscle antigens, gastric parietal cells, mitochondria, and striated muscle by indirect immunofluorescent microscopy. Rheumatoid factor was measured by a latex agglutination test, and thyroid microsomal and thyroglobulin antibodies were measured by a hemagglutination assay. Immunofluorescence assays were considered positive if antibodies were detected at a serum dilution of 1:20. All positive samples were retested at increasing dilutions until immunofluorescence or agglutination could not be detected. The control population consisted of 52 normal, healthy, ovulatory, and nonpregnant women. The study population consisted of 84 pregnant women, none of whom had a known autoimmune disorder. The mean ages of the two groups were 32 and 26 years, respectively. The frequency of autoantibody detection was not significantly different in comparing the study (46.2) and control groups (40.5). The results did not support the hypothesis that pregnancy has an effect on the induction or suppression of autoantibody production. Previous studies that suggested differences may have been influenced by the lack of a control group.

Collagen-induced arthritis and pregnancy in mice: the effects of pregnancy on collagen-induced arthritis and the high incidence of infertility in arthritic female mice

Collagen-induced arthritis (CIA) in mice is a model of inflammatory polyarthritis that has many features similar to human rheumatoid arthritis. In rheumatoid arthritis, pregnancy leads to amelioration of the disease while exacerbation develops after delivery. We used the CIA model to elucidate the role of pregnancy on disease and vice versa. The onset of arthritis in pregnant mice was delayed in the B10.RIII strains immunized with native porcine type II collagen 7-12 days prior to syngeneic [B10.RIII (susceptible to CIA) X B10.RIII] and allogeneic (B10.RIII female X B10.K male that are CIA resistant) pregnancy. In contrast, when mice were immunized on days 1-6 of pregnancy, the onset of arthritis was earlier as compared with controls. In addition, once the mice developed CIA after delivery, the disease showed markedly rapid progression as compared to the control immunized group. Humoral immune responses to type II collagen showed significantly decreased levels on day 14 (at late stage of pregnancy) both in syngeneic and allogeneic postmating immunized pregnant mice. The same effect was also seen in allogeneic premating immunized pregnant mice on day 21 (at mid-stage of pregnancy). The levels of these antibodies increased after delivery. Subclasses of IgG1 and IgG2a antibodies to type II collagen were suppressed during pregnancy. In the pseudopregnant group, these antibodies showed decreased levels on day 14, but did not differ from the control groups on day 21 and 28. Some immunoregulatory changes may play a role in these alterations in pregnant arthritic mice. In comparison to the effects of syngeneic (susceptible X susceptible) pregnancy on CIA, allogeneic (susceptible female X resistant male) pregnancy seemed to be beneficial for the affected individuals. Litter size and mean birth weight were not affected by immunization of type II collagen. After onset of CIA, both syngeneic and allogeneic matings failed to produce offspring in arthritic female mice. The estrus cyclicity was highly disturbed in arthritic female mice and gonadotropin stimulation in arthritic mice induced significantly less ova in oviducts and maturing follicles as compared to nonarthritic controls. Immunological factors yet to be elucidated may be involved in this ovarian dysfunction.

[Antinuclear antibodies in diagnosis of rheumatic diseases (author's transl)]

Hundred ana-positive sera--60 sera of SLE-patients and 40 sera of patients suffering from rheumatoid arthritis--were investigated for ana and DNA-antibodies. For these purposes nine different methods including several radioimmunological and immunofluorescence techniques with partially distinct antigen-specificities were tested. While the radioimmunoassays showed only slightly different results, significant differences in sensitivity as well as in antibody specificity existed mainly in the indirect immunofluorescence techniques using different substrates. For clinical use, a combination of various techniques seemed to be useful i.e. indirect immunofluorescence on hemolysed bird erythrocytes and on frozen native rat liver sections. For DNA-antibodies in diagnosis and control during the course of the diseases the radioimmunoassay with simultaneous detection of antibodies to single- and double stranded DNA is most suitable. Antibodies to distinct nuclear antigens are detectable in various amount in the rheumatic diseases. While ds-DNA-antibodies seemed to be most specific for SLE, ss-DNA-antibodies occurred in nearly all ana-positive sera and seemed to be less specific for one disease than all the other ana-fractions.

Antinuclear antibodies (ANA): immunologic and clinical significance

The methods currently used for the detection of ANA have been analyzed, with emphasis on their practical application to the diagnosis of the CTD. The use of the indirect IF-ANA test was recommended as a screening procedure to detect ANA. The need to standardize the technique using a single substrate and fluorescent conjugates with uniform F/P ratios was stressed. Most importantly, the value of titrating ANA for the diagnosis of the CTD was discussed. ANA titers higher than 1/500 are usually very significant clinically, often found in spontaneous or drug-induced SLE and few other CTD. The immunologic aspects of ANA and their potential value as aids in the diagnosis and management of the CTD were discussed. Anti-nDNA antibodies have been found to have a high degree of specificity for SLE and high titers of these antibodies correlate well with low levels of serum complement and severity of kidney involvement. The spectrum of ANA in the sera from patients with SLE has been expanded with the finding of anti-Sm antibodies which, when detected by gel precipitation with prototype serum, have been found so far only in SLE. Some of these antibodies have been found to have prognostic significance. Patients with MCTD and a group of patients with SLE have high titers of serum ANA with specificity for an RNase-sensitive component of ENA. The group of SLE patients defined by the presence of these antibodies (anti-Mo) have a better prognosis and in general develop only mild nephritis or have no kidney involvement at all. High titers of pure antinucleolar antibodies probably are found almost exclusively in the sera of patients with scleroderma. Some ANA have organ specificity, and GS-ANA have been found in all patients with Felty's syndrome and in a large proportion of patients with RA. One of the great advances in the field has been the recognition that ANA can be induced in the human and in experimental animals by the use of a number of therapeutic agents. Some of these agents can also induce a clinical picture resembling spontaneous SLE, though kidney involvement does not occur or is extremely mild. It is interesting that the whole spectrum of ANA can be found in drug-induced LE except anti-nDNA antibodies which have been associated to the pathogenesis of immune complex nephritis in spontaneous SLE. There is no doubt that research on ANA has contributed a great deal to the understanding of the CTD and will continue to be a valuable tool for the clinician and the investigator.