High Antinuclear Antibody Research Articles

Antinuclear antibody status and risk of death in children and adolescents

Objectives: The association between the presence of antinuclear antibodies (ANA) and mortality has been rarely reported. The present study explored the value of ANA as a predictor of overall survival in children and adolescents.Methods: Patients younger than 20 years who underwent ANA testing in Chang Gung Memorial Hospital (CGMH) from 2000 to 2008 were enrolled in this study. Mortality was ascertained by using the National Death Registry of Taiwan. Positive ANA titres were categorized as low (1:40 to 1:80), medium (1:160 to 1:320), and high (≥ 1:640).Results: A total of 13 345 subjects (6579 males, 6766 females) were enrolled during the 9-year study period. The overall prevalence of low, medium, and high ANA titres was 20.8% (n = 2774), 6.0% (n = 804), and 2.5% (n = 338), respectively. During 45 140 person-years of follow-up, 146 deaths were identified and the crude mortality rates were 3.8 and 3.0 per 1000 person-years for subjects with positive and negative ANA test results, respectively (p = 0.130). Compared with ANA-negative subjects, the adjusted hazard ratio (HR) for all-cause mortality among those with a high ANA titre was 5.18 [95% confidence interval (CI) 3.13–8.57]. A low-to-medium ANA titre was not associated with increased mortality. Among the 18 deaths in individuals with a high ANA titre, 14 were due to systemic lupus erythematosus (SLE). In comparison, five out of 34 deaths among those with low-to-medium titres of ANA and none of those with negative ANA were related to SLE.Conclusions: Children and adolescents with high ANA titres should receive greater attention and monitoring to prevent unfavourable outcomes because they have a higher mortality risk than those with negative ANA results.

Modulation of Serum Antinuclear Antibody Levels by Levamisole Treatment in Patients With Oral Lichen Planus

Serum autoantibodies, including antinuclear antibodies (ANAs), have been found in patients with oral lichen planus (OLP). This study evaluated whether Taiwanese OLP patients had significantly higher frequencies of serum ANAs than healthy control subjects, and whether levamisole treatment could modulate the antibody levels. This study used an indirect immunofluorescence technique to measure the baseline serum levels of ANA in a group of 583 Taiwanese OLP patients and 53 healthy control subjects. Seventy-nine ANA-positive OLP patients were treated with levamisole under a regular follow-up schedule in our dental clinic, and their serum ANA levels were measured after treatment. We found that the frequencies of serum ANA in patients with OLP (23.2%), erosive OLP (EOLP, 23.8%), major EOLP (31.5%), and minor EOLP (18.1%) were all significantly higher than that (5.7%) in healthy control subjects. In addition, major EOLP patients had a significantly higher serum ANA positive rate than minor EOLP or non-erosive OLP patients. Of 135 ANA-positive OLP patients, 79 were treated with levamisole under a regular follow-up schedule. We found that treatment with levamisole for a period of 2-38 months (mean, 12 ± 9 months) effectively reduced the high mean serum ANA titer (557 ± 98) at baseline to an undetectable level (0) in all ANA-positive OLP patients, regardless of different high initial serum titers of ANA. There was a significantly higher frequency of serum ANA (23.2%) in Taiwanese OLP patients than in healthy control subjects. Treatment with levamisole for 2-38 months reduced the high serum ANA to an undetectable level, and significantly improved the signs and symptoms in all treated OLP patients.

Risk factors for ANA positivity in healthy persons.

IntroductionThe finding of antinuclear antibody (ANA) positivity in a healthy individual is usually of unknown significance and in most cases is benign. However, a subset of such individuals is at risk for development of autoimmune disease. We examined demographic and immunological features that are associated with ANA positivity in clinically healthy persons to develop insights into when this marker carries risk of progression to lupus.MethodsBiological samples from healthy individuals and patients with systemic lupus erythematosus (SLE) were obtained from the Dallas Regional Autoimmune Disease Registry (DRADR). Measurements carried out on serum samples included ANA, extractable nuclear antibodies (ENA) and autoantibody profiling using an array with more than 100 specificities. Whole blood RNA samples from a subset of individuals were used to analyze gene expression on the Illumina platform. Data were analyzed for associations of high ANA levels with demographic features, the presence of other autoantibodies and with gene expression profiles.ResultsOverall, ANA levels are significantly higher in females than in males and this association holds in patients with the autoimmune diseases lupus and rheumatoid arthritis (RA) as well as in healthy controls (HC). Age was not significantly associated with ANA levels and the elevated ANA values could not be explained by higher IgG levels. Another autoantibody, anti- cyclic citrullinated peptide (CCP), did not show gender dimorphism in rheumatoid arthritis (RA) or healthy individuals. The autoantigen array showed significant elevations of other autoantibodies in high ANA HCs. Some of these autoantibodies were directed to antigens in skin and others were related to autoimmune conditions of kidney, thyroid or joints. Gene expression analyses showed a greater prevalence of significantly upregulated genes in HCs with negative ANA values than in those with significant ANA positivity. Genes upregulated in high ANA HCs included a celiac disease autoantigen and some components of the Type I interferon (IFN) gene signature.ConclusionsRisks for ANA positivity include female gender and organ-specific autoimmunity. Upregulation of skin-specific autoantibodies may indicate that early events in the break of tolerance take place in cutaneous structures. Some of these changes may be mediated by Type I IFN. Blood profiling for expressed autoantibodies and genes has the potential to identify individuals at risk for development of autoimmune diseases including lupus.

The initial manifestations and final diagnosis of patients with high and low titers of antinuclear antibodies after 6 months of follow-up

The antinuclear antibody (ANA) test is the most commonly used test to screen for autoimmune diseases. However, only a limited numbers of studies have addressed the characteristics of patients positive for ANA. In this study, we aimed to clarify the relationship between initial presentations, ANA titer, and final diagnoses. Patients who visited National Taiwan University Hospital and received a first ANA test were enrolled and then followed for a further 6 months. The symptoms and signs at the time of ANA testing, ANA titers, and the final diagnoses were recorded and analyzed. A total of 355 patients were positive for ANA. Joint pain was the most common initial presentation at the time of ANA testing. Compared with the patients with low ANA titers (<1:640), those with high ANA titers (≥ 1:640) were more susceptible to autoimmune diseases. More importantly, of the patients with initial presentations of joint pain, fever, abnormal urinalysis, or skin rash/skin tightness, autoimmune diseases were more frequently diagnosed in those with high ANA titers than with low ANA titers (p<0.05). In addition, both anti-double strand DNA antibodies and anti-extractable nuclear antibodies were more commonly detected in patients with high ANA titers. A high ANA titer seems to be a useful biomarker for the diagnosis of autoimmune diseases, especially for patients presenting with joint pain, fever, abnormal urinalysis, or skin rash/skin tightness.

False-Positive Human Immunodeficiency Virus Antibody Test and Autoimmune Hemolytic Anemia in a Patient with Angioimmunoblastic T-Cell Lymphoma

A 44-year-old woman was admitted with generalized lymphadenopathy, which was diagnosed as angioimmunoblastic T-cell lymphoma (AITL). The patient showed autoimmune hemolytic anemia (AIHA), polyclonal hypergammaglobulinemia and a high antinuclear antibody titer. Moreover, a human immunodeficiency virus (HIV)-1/2 screening test using the particle agglutination method was reactive. After chemotherapy for AITL, the AIHA was eliminated, and the false-positive HIV results were no longer detected. Autoimmunity associated with AITL is the likely cause of the cross-reaction with HIV and the AIHA. It is important to recognize that the cross-reaction with HIV can be a potential complication in AITL as well as AIHA.

Fitness Correlates of Heritable Variation in Antibody Responsiveness in a Wild Mammal

A functional immune system is important for survival in natural environments, where individuals are frequently exposed to parasites. Yet strong immune responses may have fitness costs if they deplete limited energetic resources or cause autoimmune disease. We have found associations between fitness and heritable self-reactive antibody responsiveness in a wild population of Soay sheep. The occurrence of self-reactive antibodies correlated with overall antibody responsiveness and was associated with reduced reproduction in adults of both sexes. However, in females, the presence of self-reactive antibodies was positively associated with adult survival during harsh winters. Our results highlight the complex effects of natural selection on immune responsiveness and suggest that fitness trade-offs may maintain immunoheterogeneity, including genetic variation in autoimmune susceptibility.

Identification of the etiologies of chronic urticaria in children: A prospective study of 94 patients

The etiologies of chronic urticaria (CU) in childhood remains incompletely understood because of limited data in children. The objective of this study was to examine some of the possible etiologies of CU in children by focusing on the functional autoantibody to FcepsilonRIalpha and IgE, thyroid autoimmunity, urticarial vasculitis, parasitic infestation and food allergy. Children 4-15 yr of age with CU were investigated for complete blood count, erythrocyte sedimentation rate (ESR), antinuclear antibody (ANA), CH(50), free-T4 (FT(4)), thyroid stimulating hormone (TSH), anti-thyroglobulin and anti-microsomal antibody, autologous serum skin test (ASST), skin prick tests (SPT) for foods, food challenges, and stool examination for parasites. Ninety-four children who met the criteria for CU were recruited. Patients with physical urticaria were excluded. Eosinophilia and elevated ESR were found in 23% and 13%, respectively. High ANA titers were found in 2%. None of these patients had clinical features of urticarial vasculitis, abnormal CH(50) level, abnormal TSH and FT(4). Anti-thyroglobulin and anti-microsomal antibodies were not detected. Positive ASST was found in 38%. There were no differences in medication requirement and CU remission between patients with positive and negative ASST. Parasites were found in 5% without clinical correlation. SPT to foods was positive in 35%. Positive food challenges were found in six/nine patients with positive history of food allergy and two/seven patients with negative history. Food avoidance was beneficial to the subgroup of patients with positive history of food allergy only.

Autoimmune Response of IgE Antibodies to Cellular Self-Antigens in Systemic Lupus Erythematosus

Background: Systemic lupus erythematosus (SLE) patients may exhibit high total IgE and antinuclear IgE antibodies (ANA-IgE). Here, we investigated the specificity of ANA-IgE in SLE patients and the involvement of cytokines in this immune response. Methods: Sera from 92 SLE patients and 68 healthy controls were evaluated for the presence of antinuclear IgE antibodies by immunoperoxidase with HEp-2,000® cells and immunoblotting with IgG-depleted sera. Total IgE, IgE specific to allergens, and serum cytokine levels were determined by ELISA. Results: Antinuclear IgE antibodies were detected only in SLE patients (29/92, 31.5%). High total IgE was associated with ANA-IgE (p < 0.0001), but was not associated with IgE antibodies to allergens. In the immunoblotting, ANA-IgE reacted with nucleosomes (23/29, 79.3%), dsDNA (14/29, 48.3%), SS-A/Ro (14/29, 48.3%), SS-B/La (2/29, 18.7%), Sm (14/29, 48.3%) and RNP (18/29, 62.1%). Patients with ANA-IgE had very low serum IL-4, less IL-5 than controls (p < 0.05), more IL-10 than seronegative patients (p < 0.05), and unaltered IFN-γ levels. The IL-5/IL-10 ratio was lower in ANA-IgE seropositive patients in comparison with either seronegative patients (p < 0.05) or healthy controls (p = 0.001). Controls displayed higher IL-5/IFN-γ ratios than either SLE patients with ANA-IgE (p < 0.05) or patients without these immunoglobulins (p < 0.01). Conclusions: We conclude that IgE antibodies against cell autoantigens involved in protein expression, cellular proliferation, and cell death are present in patients with SLE. Interleukin-10 seems to down-regulate this IgE autoimmune response in SLE.

An unusual case of undifferentiated connective tissue disease presenting as cardiac tamponade

Cardiac tamponade as an initial manifestation of undifferentiated connective tissue diseases (UCTD) is extremely rare, with only one case reported in literature thus far. We describe here, a case of a middle-aged man who presented with symptoms of fatigue, exertional dyspnea and orthopnea. His physical exam was significant for anasarca, elevated JVP and pulsus paradoxus. Chest X-ray showed pleural effusions and cardiomegaly, electrocardiogram revealed electrical alternans and a transthoracic echocardiogram demonstrated massive pericardial effusion with hemodynamic compromise. There was clear evidence of tamponade on right heart catheterization. All common causes of pericardial effusion were assiduously excluded before working up the patient for connective tissue disorders, which revealed a high antinuclear antibody titer (1:160), grossly elevated SSA, SSB antibodies and increased C-reactive protein levels (13.04 mg/dl). Patient had no signs or symptoms suggestive of systemic sclerosis (xerophthalmia or xerostomia) and did not meet criteria for any other known connective tissue diseases. He was therefore diagnosed with UCTD, and successfully treated with colchicine after emergency pericardiocentesis. This case presents UCTD as a rare cause of cardiac tamponade and large pericardial effusions and suggests that colchicine can be used to treat UCTD-associated effusions. These patients once diagnosed, are at risk of developing known connective tissue diseases within 5 years of disease onset and should be followed up in clinic periodically.

Discoid lupus erythematosus in a patient with scleroderma and hepatitis C virus infection

A 49-year-old Japanese woman presented with discoid lupus erythematosus (DLE) on the face. The presence of Raynaud's phenomenon, swollen fingers, a high anti-nuclear antibody titer, and the results of a biopsy revealed limited-type systemic sclerosis (lSSc). The association of SSc with DLE is rare, although some single case reports have been published in Japan. Our patient was positive for hepatitis C virus infection. Racial predisposition and immune imbalance are proposed to have played a role in the development of these lesions in our case.

Heterogeneous Nuclear Ribonucleoprotein H1, a Novel Nuclear Autoantigen

Serum samples from patients with autoimmune connective tissue diseases that show a finely speckled antinuclear antibody (ANA) on indirect immune-fluorescence often have antibodies against unknown nuclear target antigens. To search for such autoantigens we applied a proteomic approach using sera from patients with a high ANA titer (>or=640) and finely speckled fluorescence but in whom no antibodies to extractable nuclear antigens (ENA) could be identified. Using an immunoproteomics approach we identified heterogeneous nuclear ribonucleoprotein H1 (hnRNP H1) as a novel nuclear target of autoantibody response. Recombinant rat hnRNP H1 reacted in Western blot analyses with 48% of 93 sera from patients with primary Sjögren syndrome and with 5.2% of 153 sera from patients with other connective tissue diseases (diseased controls). For comparison, the diagnostic sensitivity and specificity of anti-Sjögren syndrome A (SSA) antibodies for primary Sjögren syndrome in the same patient cohort were 88.2% and 76.3%, respectively. Interestingly, 5 of 11 primary Sjögren syndrome patients with no anti-SSA or anti-SSB antibodies had anti-hnRNP H1 antibodies. Anti-hnRNP H1 antibodies were preabsorbed by hnRNP H1, as demonstrated by indirect immunofluorescence. In an evaluation of the presence of anti-hnRNP H1 antibodies in 188 consecutive samples submitted to the clinical laboratory with positive ANA (titer >or=160), anti-hnRNP H1 antibodies were found in 3 of 7 (2 primary and 5 secondary) Sjögren syndrome patients and in 8.3% of the diseased controls. HnRNP H1 is a newly discovered autoantigen that could become an additional diagnostic marker.

Long-term rheumatologic complications of sulfur mustard in victims of Sardasht, Iran

Sulfur mustard (SM) is an alkylating agent used several times by Iraqi forces as a chemical warfare agent in the Iraq-Iran war (1980–1988). Eyes, skin and respiratory system are the most sensitive organs to SM exposure. This agent has a suppressor effect on the immune system. As we did not find any study on the late rheumatologic complications of SM in the exposed victims in literature, in this study we investigated these complications in Sardasht (Iran) civilians 20 years after exposure. In a cohort study, 370 victims of Sardasht (that divided into two groups: hospitalized, n = 167, and non hospitalized, 203) in comparison to 128 control subjects from Rabat (Iran). The chief rheumatologic complaints, the physical examinations, the most probable clinical diagnosis and the rheumatic laboratory tests were compared between the study groups. The chief complaint was lower extremity pain; the most frequent physical finding was widespread tenderness and the most frequent clinical diagnosis was psychogenic pain. Among laboratory tests, only anti nuclear antibody (ANA) had significantly higher titer in the hospitalized victims than in the control subjects (P = 0.02). The most frequent rheumatologic complications were degenerative diseases of joints and spine. There was no significant difference in inflammatory disease between the two groups, but there were more rheumatoid arthritis patients among the victims. Higher ANA titers may indicate some autoimmune disorders as late rheumatic complications of SM.

Antigen-specific responses and ANA production in B6. Sle1b mice: A role for SAP

B6. Sle1b mice, which contain the Sle1b gene interval derived from lupus prone NZM2410 mice on a C57BL/6 background, present with gender-biased, highly penetrant anti-nuclear antibody (ANA) production. To obtain some insight into the possible induction mechanism of autoantibodies in these mice we compared antigen-specific T dependent (TD) and T independent (TI-II) responses between B6. Sle1b and B6 mice before the development of high ANA titers. Our results show that B6. Sle1b mice mount enhanced responses to a TI-II antigen. Additionally, the memory T cell response generated by a TD antigen also increased. This enhancement correlates with the greater ability of B cells from B6. Sle1b mice to present antigen to T cells. The SLAM Associated Protein (SAP) is critical for signaling of many of the molecules encoded by the SLAM/CD2 gene cluster, candidates for mediating the Sle1b phenotype; therefore, we also investigated the effect of sap deletion in these strains on the TD and TI-II responses as well as on ANA production. The results of these studies of responses to non-self-antigens provide further insight into the mechanism by which responses to self-antigens might be initiated in the context of specific genetic alterations.

A case of adult-onset Satoyoshi syndrome with gastric ulceration and eosinophilic enteritis

The patient was misdiagnosed as having Sjögren's syndrome (on the basis of a lower-limb rash and dry eyes and mouth) in 1999, and then as having systemic lupus erythematosus (on the basis of hair loss and a high antinuclear antibody titer) in 2005. Total alopecia, muscular spasms and diarrhea developed over the following 2 years, and the patient experienced gastric ulceration in 2006. A rheumatologic opinion was sought in 2007. Physical examination, CBC, glucose tolerance test, iron studies, HLA typing, immunological investigations and complete gastrointestinal investigations, including gastroscopy, colonoscopy and small bowel biopsy. Satoyoshi syndrome with autoimmune features (high levels of antinuclear antibody and antibodies to thyroid tissue) and malabsorption due to eosinophilic enteritis. This patient is only the fifth adult in the world reported to have Satoyoshi syndrome, and the first-reported adult case from South Africa. The patient had only a transitory response to glucocorticoid treatment. Complete amelioration of symptoms resulted on two occasions when treated with intravenous immunoglobulin; however, the remissions only lasted for 6-8 weeks. More-intensive immunosuppression with azathioprine is currently being attempted.

Outcome of high titer antinuclear antibody positivity in individuals without connective tissue disease: a 10-year follow-up

To ascertain the development of disease in a cohort of connective tissue disease (CTD)-negative patients 10 years after testing positive for antinuclear antibody (ANA) in high titer, a telephone survey and serological tests were conducted on a group of CTD-negative patients with high ANA titer identified in a previous study. Thirty-four out of 62 patients (55%) completed only the telephone survey and 27 completed both. The mean length of follow-up was 11.5 years. The ages ranged from 27 to 89 years with the mean being 58.9 years. The sex distribution included 4 (12%) men and 30 (88%) women. Twenty-one out of 27 patients (78%) remained ANA-positive. A total of five patients were diagnosed with CTD with two in the last 5 years. Common symptoms described, in order of frequency, were joint pain, Raynaud's phenomenon, and Sicca symptoms. This study shows that a considerable percentage of CTD-negative individuals with an initial high ANA titer continue to maintain their positivity even after an extended period. It is reassuring, however, that only a small number of these individuals go on to develop CTD. It confirms the fact that the ANA test, despite remaining a useful clinical tool, needs to be used in conjunction with other evidence and clinical judgement when attempting to validate the diagnosis of CTD.

Prevalence and patterns of anti‐nuclear antibodies in Korean children with juvenile idiopathic arthritis according to ILAR criteria

Objectives: To investigate the prevalence and patterns of anti‐nuclear antibodies (ANA) in different subtypes of juvenile idiopathic arthritis (JIA) according to the International League of Associations for Rheumatology (ILAR) criteria.Methods: One hundred and fifty‐three Korean patients (M:F 83:70) with JIA were followed between 1990 and 2006 and were tested for ANA by an indirect immunofluorescence method using HEp‐2 cells as the substrate. ANA tests were repeated in 37 patients during the course of the disease. The median age at onset was 7.5 years (range 0.8–15.9 years).Results: ANA were positive in 50 (33%) of the 153 patients at a dilution of 1:40 or higher (>1:40 in 70%, >1:80 in 2%, >1:160 in 16%, >1:320 in 2%, and >1:640 in 10%). The patterns of immunofluorescence staining were homogeneous in 50%, speckled in 38%, nucleolar in 8%, and centromere in 4%. ANA titres were decreased in 25 (68%) of the 37 patients, and the nuclear fluorescence patterns changed in 14 (38%) during follow‐up. ANA seropositivity was associated with female sex (p<0.0001), negative HLA‐B27 (p = 0.01), and a persistently elevated erythrocyte sedimentation rate (ESR) at follow‐up (p = 0.014). Furthermore, a high ANA titre (>1:160) was associated with a poor clinical outcome (active patients at follow‐up) (p = 0.005).Conclusions: ANA may be an important marker of disease activity in patients with JIA. ANA titres tend to decrease during disease remission but the fluorescence patterns do not appear to be related to disease activity or clinical outcome.

56-jährige Patientin mit Raynaud-Symptomatik, erhöhten Leberenzymen und neuropsychiatrischen Symptomen

A 56-year-old woman presented with increased liver enzymes (GPT, GOT), arthralgias, Raynaud's syndrome and disturbance of sleep and concentration. Serology and liver biopsy indicated chronic hepatitis C infection (HCV) and viral-induced liver cirrhosis with unremarkable liver synthesizing parameters. An HCV-triggered cryoglobinemia was excluded, but high elevated antinuclear antibodies (ANA) and anti-RNP autoantibodies, typical serological parameters of mixed tissue collagenous (Sharp}s disease), were detectable. Magnetic resonance spectroscopy (H-MRS) was performed to differentiate between cerebral vasculitis and mild hepatic encephalopathy. This detected abnormal pattern of cerebral metabolites (myo-inositol and choline), is specific for HE. After onset of an antiviral therapy (terferon/ribavirin), low protein diet with supplementation of l-ornithine-l-aspartate the arthralgia and neuropsychiatric symptoms rapidly improved and HCV-RNA PCR became negative. Unfortunately, after cessation of antiviral treatment the patient had a relapse of HCV with a worsening of the arthralgia and the Raynaud symptoms (HCV-triggered Sharp}s disease). Even in patients with mildly abnormal liver function and liver cirrhosis it is important to consider (mild) hepatic encephalopathy if neuropsychiatric symptoms occur.

Infections in infancy and the presence of antinuclear antibodies in adult life

There has been limited success defining environmental factors important to the development of connective tissue diseases such as systemic lupus erythematosus (SLE). Recent work has suggested that the perinatal environment may be important. To investigate this we measured antinuclear antibodies (ANA) in a general population with well-defined early lives to see whether fetal and infant growth and infections were associated with ANA positivity in adult life. Included in our investigation were 1334 individuals (668 men, 666 women) from the Hertfordshire cohort study. ANA was measured using an ANA ELISA and confirmed using immunofluorescence. We investigated associations between the presence of ANA and early growth and infectious exposure in infancy in men and women combined, but with adjustment for gender throughout. A positive ANA was present in 73 (10.9%) of men and 81 (12.2%) women. Of these, 26 women and 14 men were positive using IF on HEP2 cells. Sharing a bedroom during childhood was associated with a higher risk of being ANA positive (odds ratio (OR), 1.42, 95% confidence interval (CI) 1.00-2.01, P = 0.05). A record of diarrhoeal illness (OR 2.12 95% CI 1.07, 4.23, P = 0.03) and rubella or mumps during the first year of life (OR 16.12, 95% CI 2.92, 88.94, P = 0.001) was also significantly associated with ANA in adult life. Higher ANA titres by Inova ELISA were associated with infections in the first year of life from mumps (2.74-fold higher, 95% CI 0.98, 7.64, P = 0.05) and rubella (3.90-fold higher, 95% CI 1.89, 8.04, P < 0.001). In addition, higher ANA titres were also associated with mumps (1.26-fold higher, 95% CI 1.02, 1.56, P = 0.03) between one and five years of age. Our results suggest that a developing immune system exposed to increased infection is more likely to produce ANA in adult life and perhaps begin the pathological process that leads to SLE.

Utility of age, gender, ANA titer and pattern as predictors of anti-ENA and -dsDNA antibodies

Monovariate and multivariate analyses including logistic regression were performed to determine associations among predicting variables [age, gender, immunofluorescence pattern, and anti-nuclear antibody (ANA) titer] and anti-extractable nuclear antigen (ENA) and -dsDNA antibodies (Abs) in 1089 patients with positive fluorescent ANA (FANA) test results. Samples with high titer ANAs had an increased frequency of anti-ENA and -dsDNA Abs. The receiver operating (ROC) curves of the ANA titer for anti-ENA Abs had a larger under the curve area compared to the ROC curve for anti-dsDNA Abs, indicating that ANA titer is better for predicting anti-ENA Abs than anti-dsDNA Abs. There was no relation noticed between immunofluorescence patterns and anti-ENA and -dsDNA Abs except an increased frequency of anti-dsDNA Abs found in samples with a homogeneous pattern. Probability calculations on the basis of the ANA pattern and the titer showed that samples with low titer ANAs (1:160 or less) had low probabilities for anti-ENA Abs (0.002-0.009) regardless of immunofluorescence patterns. However, samples with a homogeneous pattern at any titers including low titers had high probabilities for anti-dsDNA Abs. A decreased frequency of anti-dsDNA Abs as measured by Crithidia assay was noticed in samples from patients aged 50 or older. In contrast, no association was noticed between age and anti-ENA Abs. There was no female preponderance found in the presence of anti-ENA and -dsDNA Abs. In conclusion, our study shows that the ANA titer but not the immunofluorescence pattern is useful in predicting anti-ENA Abs. In contrast, both the ANA titer and the immunofluorescence pattern help in predicting anti-dsDNA Abs. Samples with low titer ANAs (1:160 or less) may not need a further test for anti-ENA Abs unless an ANA-associated disease is highly suspected. However, a test for anti-dsDNA Abs should be considered in samples with a homogeneous pattern at any titer including low titers.

Antinuclear antibodies can be detected in dog sera reactive to Bartonella vinsonii subsp. berkhoffii, Ehrlichia canis, or Leishmania infantum antigens.

The presence of antinuclear antibodies (ANAs) is used to support a clinical diagnosis of systemic lupus erythematosus (SLE) in dogs. However, clinicians must interpret the detection of ANAs with caution, particularly in light of increasing evidence that dogs with known bacterial and protozoal infections can have high ANA titers. Retrospectively, medical records were reviewed for all dogs that were concurrently tested for antinuclear antigens and Bartonella vinsonii (berkhoffii), Ehrlichia canis, or Rickettsia rickettsii antigens between 1990 and 2000. When analyzed on the basis of reactivity to a specific infectious agent, 75% of the B vinsonii (berkhoffii) seroreactors, 16.7% of the E canis seroreactors, and 0% of the R rickettsii seroreactors had concurrent ANAs. Subsequent prospective testing did not detect ANAs in convalescent sera from dogs experimentally infected with B vinsonii (berkhoffii), E canis, or R rickettsii. However, 10-20% B vinsonii (berkhoffii), E canis, or Leishmania infantum reactive sera from naturally infected dogs contained ANAs. In addition, 45% of sera from dogs that are reactive to multiple vectorborne organisms were more likely to contain ANAs when compared to sera from dogs reactive to only 1 test antigen. When interpreting the relevance of seroreactivity to nuclear antigens, clinicians should recognize that dogs with seroreactivity to B vinsonii (berkhoffii), E canis, or L infantum antigens (especially those with seroreactivity to more than one of these pathogens) may produce ANAs.