Prevalence Of Antinuclear Antibodies Research Articles

Relationship between antinuclear antibody and microalbuminuria in the general population: the Takahata study

Microalbuminuria, a marker of vascular damage, is associated with increased risk of progressive renal deterioration, cardiovascular disease and mortality. However, the relationship between antinuclear antibody (ANA) and microalbuminuria in the general population is unknown. Thus, we conducted a cross-sectional study to examine the relationship between ANA and microalbuminuria. The subjects of this community-based study were individuals over 40 years old in Takahata, Japan. The urine albumin-creatinine ratio (UACR) was calculated from a single-spot urine specimen collected in the morning. ANA was examined by enzyme immunoassay (EIA). Among the 2,875 subjects (mean age 63 years; men 1,276; women 1,599), positive ANA (ANA index >or=20.0) was detected in 16.9% of the total population (men 12.9%, women 20.3%) and the prevalence of positive ANA increased with age. The prevalence of microalbuminuria (UACR 30-300 mg/g), but not macroalbuminuria (UACR > 300 mg/g), was significantly higher in the positive ANA group than the negative ANA group (24.1% vs. 16.0%, respectively, P < 0.001). Along with the increase of the ANA index, the prevalence of microalbuminuria and UACR levels were increased. Multivariate logistic regression analyses showed that ANA was significantly associated with microalbuminuria (odds ratio [OR] 1.63 and 95% confidence interval [95%CI] 1.27-2.10). These associations were significant in women, but not men, when examined separately. These results indicate that the presence of ANA is associated with microalbuminuria in the general population, especially women.

Antinuclear antibody is associated with a more advanced fibrosis and lower RNA levels of hepatitis C virus in patients with chronic hepatitis C

Aims:Positive serum antinuclear antibody (ANA) is present in a number of patients with chronic hepatitis C virus (HCV) infection. This study aimed to evaluate the prevalence of ANA in patients...

Rheumatological manifestations, organ damage and autoimmunity in hereditary C2 deficiency

To analyse rheumatological manifestations, organ damage and autoimmune responses in a large cohort of patients (n = 45) with homozygous C2 deficiency (C2D) and long-term follow-up. Medical records were reviewed and were supplemented with a mailed questionnaire for assessment of cardiovascular disease (CVD) risk factors. Organ damage was evaluated using the Systemic Lupus International Collaborative Clinics/American College of Rheumatology Damage Index (SLICC/ACR DI). Causes for disability pensions were investigated. Autoantibodies were determined with established methods. Patients with rheumatological diseases had systemic lupus erythematosus (SLE, n = 12), undifferentiated connective tissue disease (n = 5) or vasculitis (n = 3). Judging from annual SLICC/ACR DI, C2D patients with SLE run a similar risk of development of severe disease as other patients with SLE. An increased rate of CVD was observed not explained by Framingham-related risk factors. Disability pensions were mainly related to rheumatological disease. The prevalence of anti-nuclear antibodies in C2D with SLE and of anti-SS-A was 25% while anti-RNP was found in 45%. Only one patient showed antibodies to dsDNA. Formation of anti-cardiolipin antibodies (aCL) appeared to be increased in C2D despite the absence of an anti-phospholipid syndrome. The prevalence of antibodies to the collagen-like region of C1q (C1qCLR) was also remarkably high and was not related to rheumatological manifestations. Severity of SLE in C2D is similar to that of SLE in other patients. Conventional risk factors do not explain the occurrence of CVD in C2D. The high prevalence of aCL and anti-C1qCLR indicates mechanisms through which impaired complement function promotes formation of autoantibodies.

Antinuclear Antibodies and Bromoxynil Exposure in a Rural Sample

Previous research suggests that farmers may have an increased risk of developing autoimmunity and that exposure to certain pesticides may alter immune function. Little is known, however, about the immunologic effects of farming and pesticide exposures. As part of the Prairie Ecosystem Study, associations between detection of antinuclear antibodies (ANA), an autoimmunity indicator, and exposure to the herbicide bromoxynil (3,5-dibromo-4-hydroxybenzonitrile) were investigated in a cross-sectional study of 208 residents (94 women, 114 men) of a cereal-producing region in Saskatchewan, Canada, during spring herbicide application, 1996. The ANA were assayed in serum by indirect immunofluorescence on HEp-2 cells. Bromoxynil was measured in plasma by gas chromatography/mass spectrometry analysis. Associations were explored between ANA detection and detection of bromoxynil in plasma, self-reported use of bromoxynil and other pesticides, farming exposures, gender, age, body mass index (BMI), and residency. The mean age (SD) of the participants was 50.8 (13.6) yr [women: 49.7 (13.5) yr, men: 51.6 (13.6) yr]. ANA prevalence was 37.5% (women: 39.4%, men: 36%,) at 1:40 serum dilution, 17.3% (women: 20.2%, men: 14.9%) at 1:80, and 10.1% (women: 13.8%, men: 7%) at 1:160. In the multiple-variable Generalized Estimating Equation (GEE) logistic regression analyses, female gender was a positive predictor of ANA detection and gender differences were observed in the relative importance of other study factors. None of the variables examined in the multiple-variable GEE analysis were statistically significant predictors of ANA detection for women. For many of these variables, however, the point estimates for women are similar to those seen in men. For men, with adjustment for age, ANA presence was inversely associated with detection of concentrations of bromoxynil in winter or spring samples and recent occupational use of 2,4-dichlorophenoxyacetic acid, and the positive ANA predictors included having a BMI in the obese (BMI > 30.04 kg/m2) category, recent occupational use of trifluralin or fungicides, and current exposure to oilseed, poultry, or dairy production. The inverse association between ANA detection and bromoxynil exposure observed in farmers in this study is consistent with earlier empirical observations that certain pesticides may suppress immune function. Further research is needed to examine whether these findings are confirmed in other populations and to elucidate the biological mechanisms involved.

Antinuclear antibodies in the oldest-old women and men

The aim of this study was to compare the prevalence of antinuclear antibodies (ANA) in very old individuals (≥86 years of age) with healthy younger (18–68 years) blood donors ( n = 200) regarding gender, health status, ratio of circulating CD4/CD8 cells and cytomegalovirus (CMV) serology. Frozen plasma was used for ANA detection in two study groups, i.e. ‘OCTO’ (97 persons aged 86–92 years, 65% women) and ‘NONA’ (136 persons aged 86–95 years, 70% women). OCTO participants were recruited on the basis that they were healthy or moderately healthy according to a selection protocol. No exclusion criteria regarding health status were applied in the NONA sample. The prevalence of ANA was significantly higher in the oldest-old samples compared to blood donors. There was no association between health status and the presence of ANA in the oldest-old. The difference across age was most pronounced in men, with low levels at younger age, whereas the prevalence among the oldest-old men reached similar levels as in women. There were no associations between the presence of ANA and CD4/CD8 ratio or with CMV status in the oldest-old. Our findings confirm an increased prevalence of ANA in the oldest-old, and emphasize the importance of taking gender and age into consideration when evaluating ANA.

Corrélation entre présence d’anticorps anti-antigène de type 2 de la pemphigoïde et démence chez les sujets âgés sans manifestation clinique de pemphigoïde

Pemphigoid is a form of auto-immune bullous dermatosis characterised by the production of antibodies directed against components of hemidesmosomes in the basal membrane. The physiopathological process responsible for unmasking of these antigens is unknown. Pemphigoid is more common in elderly subjects and is most often seen in debilitated subjects. The prevalence of pemphigoid anti-pemphigoid antibodies (anti-PB) is not known in the elderly population presenting no dermatological signs evocative of the disease. We studied the prevalence of anti-PBAg2 antibodies in elderly subjects with no signs of pemphigoid as well as in the correlation between the presence of these antibodies and diagnosis of dementia. Elderly subjects (aged over 69 years) with no signs of pemphigoid were recruited consecutively in dermatology and geriatrics departments (138 subjects). Details of concomitant medication were recorded for all subjects and clinical examination was performed with calculation of MMS (Mini Mental Score). The subjects were then divided into two groups based on MMS score. The first group comprised subjects without dementia (MMS > 24) while the second comprised subjects with dementia. Serum anti-PBAg2 antibodies were determined by ELISA and indirect immunofluorescence with confirmation by Western blot. Antinuclear antibodies, used as a control for non-specific immune response, were assayed in all serum samples. The prevalence of these antibodies was compared between the two groups. The two groups were comparable in terms of age, sex and presence of dermatological diseases (ulcers, bedsores, erysipelas). Each group comprised 69 subjects. The overall presence of anti-PBAg2 antibodies in subjects with no signs are suggestive of pemphigoid was 3.6%. Presence of anti-PBAg2 antibodies was associated with diagnosis of dementia (p=0.04; 0% and 7% in groups 1 and 2, respectively). No correlation was seen between the presence of anti-PBAg2 antibodies and concomitant medication or dermatological disease. The overall prevalence of antinuclear antibodies was 14.5% and the figure was similar between the two groups. The presence of anti-PBAg2 could be associated with the diagnosis of dementia in elderly subjects.

Prevalence of Antinuclear Antibodies in Healthy Women

s: II Congresso Latino-Americano de Autoimmunadade Second Latin American Congress of Autoimmunity

Localized scleroderma in childhood is not just a skin disease

Juvenile localized scleroderma is usually considered a disease that is confined to the skin and subcutaneous tissue. We studied the prevalence and clinical features of extracutaneous manifestations in a large cohort of children with juvenile localized scleroderma. Data from a multinational study on juvenile scleroderma was used for this in-depth study. Clinical features of patients with extracutaneous manifestations were compared with those of patients who had exclusively skin involvement. Seven hundred fifty patients entered the study. One hundred sixty-eight patients (22.4%) presented with a total of 193 extracutaneous manifestations, as follows: articular (47.2%), neurologic (17.1%), vascular (9.3%), ocular (8.3%), gastrointestinal (6.2%), respiratory (2.6%), cardiac (1%), and renal (1%). Other autoimmune conditions were present in 7.3% of patients. Neurologic involvement consisted of epilepsy, central nervous system vasculitis, peripheral neuropathy, vascular malformations, headache, and neuroimaging abnormalities. Ocular manifestations were episcleritis, uveitis, xerophthalmia, glaucoma, and papilledema. In more than one-fourth of these children, articular, neurologic, and ocular involvements were unrelated to the site of skin lesions. Raynaud's phenomenon was reported in 16 patients. Respiratory involvement consisted essentially of restrictive lung disease. Gastrointestinal involvement was reported in 12 patients and consisted exclusively of gastroesophageal reflux. Thirty patients (4%) had multiple extracutaneous features, but systemic sclerosis (SSc) developed in only 1 patient. In patients with extracutaneous involvement, the prevalence of antinuclear antibodies and rheumatoid factor was significantly higher than that among patients with only skin involvement. However, Scl-70 and anticentromere, markers of SSc, were not significantly increased. Extracutaneous manifestations of juvenile localized scleroderma developed in almost one-fourth of the children in this study. These extracutaneous manifestations often were unrelated to the site of the skin lesions and sometimes were associated with multiple organ involvement. The risk of developing SSc was very low. This subgroup of patients with juvenile localized scleroderma should be evaluated extensively, treated more aggressively, and monitored carefully.

Do antinuclear antibodies in primary biliary cirrhosis patients identify increased risk for liver failure?

Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease with a variable clinical course. Identification of serologic markers associated with increased risk of liver failure would assist in management of PBC patients. The objective of this study was to identify antinuclear antibody (ANA) markers that may be used to predict PBC outcome. Indirect immunofluorescence was used to identify ANAs in 492 PBC patients. chi2 and Kaplan-Meier analyses were used to examine the association between ANAs and liver failure. A greater percentage of ANA-positive, compared to ANA-negative, PBC patients developed liver failure (41% vs 25%, P = .005). The presence of anti-centromere antibodies was associated with liver failure (anti-centromere antibody positive vs negative, 58% vs 33%, P = .001). The time to liver failure was shorter in ANA-positive, compared with ANA-negative, patients (log rank score 5.8, P = .02). After 8.9 years (the median follow-up for patients without liver failure), 68% of ANA-positive and 81% of ANA-negative patients were free of liver failure. Anti-centromere antibodies were also associated with a shorter time to liver failure (log rank score 8.4, P = .004). After 8.9 years, 52% of anti-centromere antibody positive and 74% of anti-centromere antibody negative patients were without liver failure. ANAs in general, and anti-centromere antibodies in particular, are associated with liver failure in PBC. PBC patients with ANAs may be candidates for treatment with experimental therapies to prolong the interval between diagnosis and liver failure. ANA-negative patients, who appear to have a relatively benign clinical course, should perhaps be treated with ursodeoxycholic acid alone.

Associations between plasma DDE levels and immunologic measures in African-American farmers in North Carolina.

Experimental studies in rodents demonstrate evidence of immunosuppressive effects of dietary exposure to DDT [2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane], but human data pertaining to immunomodulating effects of DDT exposure are limited. In this study we examined the association between the persistent organochlorine breakdown product 1,1-dichloro-2,2,bis(p-chlorophenyl)ethylene (p,p′-DDE) and immunologic measures using blood samples in a relatively highly exposed population of farmers in the United States. Levels of serum immunoglobulin A (IgA) and IgG and the prevalence of antinuclear antibodies in relation to plasma p,p′-DDE levels were evaluated in samples from 137 African-American male farmers (30–88 years of age; median, 64 years). Participants were recruited through black churches in four rural counties in eastern North Carolina. Data collection included a telephone interview pertaining to farming practices and health history, and one blood sample was collected from each participant. Linear and logistic regression, adjusting for age, cholesterol, triglycerides, smoking status, and years of any kind of pesticide use, was used to assess the association between immunologic parameters and plasma levels of p,p′-DDE. The median plasma p,p′-DDE concentration was 7.7 μg/L (range, 0.6–77.4 μg/L). There was no association between p,p′-DDE and IgA in any of the models. IgG levels decreased with increasing p,p′-DDE levels, with a statistically significant decrease of approximately 50% in the highest two categories of exposure (≥ 6.0 μg/L) compared with values of < 3.0 μg/L. Sixteen (12%) were positive for antinuclear antibodies. The prevalence of antinuclear antibodies was somewhat elevated in the highest category of p,p′-DDE exposure (odds ratio, 1.9; 95% confidence interval, 0.32–11.3; for ≥ 12.0 μg/L compared with < 3.0 μg/L p,p′-DDE), but this difference was not statistically significant. These analyses provide evidence that p,p′-DDE modulates immune responses in humans.

The prevalence of antinuclear antibody in patients with nonalcoholic fatty liver (NAFL)

The prevalence of antinuclear antibody in patients with nonalcoholic fatty liver (NAFL)

Silent nephritis in systemic lupus erythematosus.

Silent lupus nephritis (SLN) was investigated in 42 renal asymptomatic patients and compared with 49 untreated patients with overt lupus nephropathy (OLN). Urinary sediment, quantitative proteinuria, creatinine clearance, antinuclear antibodies (ANA), complement, circulating immune complexes (CIC) and renal biopsies were evaluated in all of the patients. Forty-one out of the 42 (97.6%) patients had SLN according to histopathological findings. Results showed that the mean age, female/male ratio and the clinical activity index (SLEDAI) were similar in both groups (P > 0.05). The prevalence of ANA, anti-ds DNA, anti-ENA autoantibodies and C4 serum levels showed no statistical differences between the two groups (P > 0.05). Conversely, in the OLN group, elevated CIC and diminished CH50 and C3 serum levels were significantly different (P < 0.01). WHO class II was the predominant renal lesion in the group with SLN (P < 0.0001), whereas class IV was in the OLN patients (P < 0.0001). We conclude that, in our series, SLN was highly prevalent in renal asymptomatic patients with otherwise systemic lupus erythematosus. Furthermore, abnormal levels of CIC, CH50 and C3 associated with WHO class II suggest a moderate but ongoing activation of immune-mediated renal injury mechanisms.

Chemical pregnancies: immunologic and ultrasonographic studies.

Implantation of the embryo determines successful from unsuccessful cycles after in vitro fertilization (IVF) and embryo transfer (ET). The purpose of this study was to compare immunologic risk factors among women experiencing implanation failure characterized by a negative pregnancy test after IVF/ET and those experiencing chemical pregnancies. In addition ultrasonographic measurement of gestational sac size from 24 to 35 days from last menstrual period (LMP) were compared between chemical pregnancies and other pregnancy outcomes. Blood samples from 122 women experiencing IVF implantation failure with a negative pregnancy test after ET and 20 women with chemical pregnancies were evaluated for the presence of antiphospholipid antibodies (APA), antinuclear antibodies (ANA), circulating embryotoxins (ETA) and elevated levels of natural killer (NK) cells. Gestational sac size measured from 24 to 35 days form LMP were compared according to pregnancy outcome: term birth (n = 46), ectopic pregnancy (n = 49), spontaneous abortion (n = 56) and chemical pregnancy (n = 20). Women experiencing chemical pregnancies had a higher frequency of APA than women with implantation failure associated with a negative pregnancy test (80% versus 28%, P < 0.0001). The prevalence of ANA, elevated NK cells and ETA was not different between the two groups. The mean gestational sac size from 24 to 35 days from LMP did not differ when chemical pregnancies were compared with pregnancies progressing longer than 35 days. The maximal gestational sac diameter among chemical pregnancies was 3.8 mm. Mechanisms involved in implantation failure associated with a negative pregnancy test may be different from those involved in chemical pregnancies. Chemical pregnancies may be the result of defective angiogenesis.

Familial occurrence of autoimmune diseases and autoantibodies in a Caucasian population of patients with systemic lupus erythematosus.

To determine the prevalence of autoimmune diseases and autoantibodies in relatives of Caucasian patients with systemic lupus erythematosus (SLE) we questioned 118 patients for the prevalence of autoimmune diseases in their relatives. Multicase SLE families were selected for further investigation: assessment of the presence of antinuclear antibodies (ANA), thyroid antibodies and IgM rheumatoid factor (IgM-RF). Thirty-three patients reported the presence of 50 autoimmune diseases in 43 relatives. Twenty-two diagnoses could be either confirmed (n=14) or refuted (n=8). SLE clustered significantly within families of SLE patients. Multiple sclerosis and rheumatoid arthritis also seemed to cluster within families of lupus patients. The prevalence of ANA (24%) and thyroid antibodies (44%) in 29 relatives of multicase SLE families was raised (P<0.05). In conclusion, the prevalence of autoimmune diseases is raised in relatives of Caucasian SLE patients. Also, the prevalence of autoantibodies is raised in relatives of multicase SLE families, both suggesting genetic influences in the pathogenesis of the disease. These findings support the genome-wide screening of SLE patients to unravel factors responsible for genetic susceptibility to SLE.

Expression and clinical significance of antinuclear antibody in hepatitis C virus infection.

The prevalence of antinuclear antibody (ANA) has been documented in patients with hepatitis C virus (HCV) infection. We attempted to determine the titer and to characterize the patterns and clinical significance of ANA in HCV infection. Forty-eight consecutive patients with positive anti-HCV antibody and positive HCV RNA were included in this study. Sera from patients were tested for ANA and anti-smooth muscle antibody by indirect immunofluorescence. Serum aminotransferase, alkaline phosphatase, alpha-fetoprotein, and cryoglobulin levels also were determined. Eleven (23%) of 48 HCV-infected patients were positive for ANA. Antinuclear antibody revealed speckled pattern in 10 (91%) of the 11 ANA-positive HCV-infected patients. Twenty (54%) of 37 ANA-negative HCV-infected patients had detectable pattern with equivocal titer (titer <1.5). The ANA pattern was speckled in all 20 patients. Hepatitis C virus-infected patients with positive ANA were older than the HCV-infected patients with negative ANA (62.90 +/- 11.05 years vs. 56.46 +/- 14.94 years, respectively; p < 0.1). Serum levels of aspartate aminotransferase (39.36 +/- 14.98 IU/L vs. 30.70 +/- 23.15 IU/L, p < 0.05), alkaline phosphatase (189.00 +/- 75.63 IU/L vs. 122.41 +/- 40.88 IU/L, p < 0.01), and alpha-fetoprotein (47.72 +/- 80.47 pg/dL vs. 7.00 +/- 8.28 pg/dL, p < 0.01) were higher in ANA-positive HCV-infected patients than in ANA-negative HCV-infected patients, respectively. There were no significant differences in gender, alanine aminotransferase, anti-smooth muscle antibody, or cryoglobulin between the two groups. Antinuclear antibody was present in 11 (23%) of 48 patients with HCV infection in our study. Speckled pattern is the major expression pattern of ANA in HCV infection. Antinuclear antibody-positive HCV-infected patients have significantly higher serum aspartate aminotransferase, alkaline phosphatase, and alpha-fetoprotein levels than ANA-negative HCV-infected patients.

Investigation of antinuclear antibodies in canine atopic dermatitis.

Serum samples from 40 atopic dogs and 20 healthy dogs were assayed for antinuclear antibodies (ANA) using a human epithelial cell line (HEp-2) and standard indirect immunofluorescent methods. Samples from the atopic dogs were grouped according to the presence (n = 28) or absence (n = 12) of facial lesions at any moment during the follow-up period. Positive ANA titres were found in 10 of the 40 atopic dogs analysed (25%) whereas samples from the control group were negative. Eight atopic dogs with facial lesions had a positive titre (28.57%) in contrast with atopic dogs without facial lesions where two positive samples (16.67%) were found; however, the differences were statistically not significant. Endpoint titres were low (1/40), only two samples yielded a 1/80 positive titre and one sample had a 1/320 titre, all of them from the facial lesions group. Response to immunotherapy was classified as positive only in four of the 10 ANA-positive patients (40%) compared with a response rate of 73% (22 of 30) in the ANA-negative atopic dogs. However, a Fisher's exact test showed a two-sided P-value of 0.122 which was considered statistically not significant. The overall response rate to immunotherapy for all atopic dogs was 65% (26 of 40). In conclusion, the prevalence of ANA is higher in atopic than in healthy dogs, especially if facial lesions are present. Although a clinically significant pathogenic contribution is not probable, this higher prevalence should be taken into account in the differential diagnosis of canine autoimmune dermatitis.

Primary biliary cirrhosis with antibody against carbonic anhydrase II associates with distinct immunological backgrounds

Objective: a part of patients with primary biliary cirrhosis (PBC) has anti-human carbonic anhydrase II (CA II) autoantibodies, although several contradictional reports followed. Since immunization of mice with CA II results in cholangitis in a susceptible strain, PBC with anti-CA II antibody may have distinct clinical features. Thus, we tested the sera of patients with PBC for anti-CA II antibodies and compared clinical characteristics of PBC patients with and without anti-CA II antibodies in Japanese patients. Methods: anti-CA II antibodies were detected in nine of 50 (18%) PBC patients by immunoblotting. The evaluation of these patients included various clinical parameters, autoantibodies, and immunological backgrounds. Results: the levels of serum liver tests and the prevalence of serum anti-mitochondrial antibody (77.8 vs. 92.7%) were not different between the patients with and without anti-CA II antibody. However, the prevalence of anti-nuclear antibody (ANA) was significantly higher in the patients with anti-CA II antibody than that in the patients without anti-CA II antibody (66.7 vs. 25.6%, P=0.044), although their mean titers were not statistically different. Association of Sjøgren's syndrome tended to be more frequent in the patients with anti-CA II antibody than those without it (33.3 vs. 14.6%, P=0.327). Studies of HLA class I allotype revealed that three of five (60.0%) patients with anti-CA II antibodies and one patients from 34 (3.0%) patients without anti-CA II antibodies had HLA B51 allotype; the difference in the prevalence of this allotype was significant ( P=0.004, Pc=0.01), and the prevalence of other HLA class I and HLA DR allotypes was similar between the patients with and those without anti-CA II antibody. Administration of ursodeoxycholic acid (600 mg per day) was accompanied by change in liver tests in a similar way between the two patient groups. Conclusions: These results suggest that, although clinical features are not distinctive, PBC patients with anti-CA II antibody may have a genetic background, which may contribute to a susceptibility to immune-mediated cholangitis.

First evaluation study of the Dutch Working Party on silicone breast implants (SBI) and the silicone-related symptom complex (SRSC).

This cohort study evaluates the postoperative prevalence of antinuclear antibodies (ANA) in relation to symptoms related to the so-called silicone-related symptom complex (SRSC). A total of 63 women who underwent mastectomy followed by immediate breast reconstruction with a silicone implant (SBI) between Septembber 1990 and May 1995 at the University Hospital Rotterdam/Daniel den Hoed Cancer Center, participated voluntarily in the study. Their sera were tested for the presence of antinuclear antibodies (ANA) and at the same time they were screened for the prevalence of SRSC-related symptoms by questionnaire. All patients were also examined physically. Sixteen per cent of the women were ANA positive. There was no difference in SRSC expression between ANA-positive and ANA-negative women. The lack of difference in symptom expression between the ANA-positive and ANA-negative women and the rather low complaint percentage proves that if ANA positivity is related to the SRSC, we found no evidence that patients with a SBI with a positive ANA differed from the ANA-negative patients.

PREVALENCE OF ANTINUCLEAR ANTIBODIES IN A RURAL POPULATION

Exposure to environmentally and occupationally encountered toxicants can be associated with the development of certain autoimmune diseases and with the induction of antinuclear antibodies (ANA). Some chemicals used in the agricultural industry are known to affect immune function but their roles in the induction of autoimmunity in general, and ANA in particular, have not been reported previously. This study was undertaken to establish the prevalence of ANA in a rural population and to determine environmental and occupational exposures with which they are associated. This cross-sectional study represented one component of an interdisciplinary project (Prairie Ecosystem Study [PECOS], Eco-Research Program, Tri-Council Secretariat of Canada) designed to explore, in a rural population, the roles of environmental exposures as determinants of human health status. Information regarding lifetime, current, and main occupational exposures in the rural-dwelling study population was derived from a self-administered questionnaire. Sera from consenting subjects, collected during the months of February and March 1996, were assayed for ANA by indirect immunofluorescence on HEp-2 cells. The study population comprised 322 adult subjects (mean age 49.3 +/- 14.7 yr; range 16-87 yr). Statistical analyses adjusted for age and sex revealed that the presence of ANA among the participants was associated with a current agricultural occupation that included oilseed production, hog production, or poultry production. There was a significant association between ANA positivity and a current main farming operation of crop production. There was also an association among individual participants between lifetime exposure to the insecticide class of pesticides and the presence of ANA. In this rural study population, ANA positivity was significantly associated with lifetime exposure specifically to carbamate, organochlorine (including aldrin, chlordane, dieldrin, endrin, heptachlor, and lindane, but excluding DDT and methoxychlor), and pyrethroid insecticides and to phenoxyacetic acid herbicides, including 2,4-D. After adjustment for age, sex, and other insecticide exposures, multivariate analyses indicated that ANA positivity was associated with current oilseed production and with lifetime exposure to pyrethroid insecticides. In a rural population, ANA were associated with production of certain crops and certain animals and exposure to specific pesticides. The data indicate that some occupational exposures related to the agricultural industry are associated with the presence of ANA, a serologic expression of autoimmunity.

A prospective study on the occurrence of autoantibodies in low-risk pregnancies

Objective: This investigation was done to study the prevalence of anti-nuclear antibodies (ANA), anti-cardiolipin antibodies (aCL), and rheumatoid factor (RF), in presumed healthy women during their pregnancies. Study design: During an 18 month period blood samples were taken in the first, second and third trimester from 1200 pregnant women, representing a low-risk population. Clinical data on the pregnancy outcome were obtained by birth statistics after their deliveries. The diagnoses of preeclampsia, intrauterine growth retardation, fetal death, or abruptio placentae were stated in 57 of these women. An age- and parity-matched control group of 207 women with normal pregnancy outcome was drawn from the same low-risk population ( n=1200). A nonpregnant control group consisted of 157 women. The prevalence of ANA (immunofluorescence microscopy on HEp-2 cells), aCL-immunoglobulin G (enzyme-linked immunosorbent assay), and RF (latex agglutination test) in preeclampsia, intrauterine growth retardation, fetal death, or abruptio placentae were compared to the normal pregnancies, and to the nonpregnant controls. Results: ANA occurred significantly more often ( P<0.05) in pregnancies complicated by preeclampsia when compared to normal pregnancies. aCL occurred sparsely in normal as well as complicated pregnancies. RF was infrequently seen among all women in this study. Conclusion: An association was noted between the occurrence of ANA and preeclampsia. However, this association was too insensitive to use as a clinical tool.