Positive Antinuclear Antibody Results Research Articles

Effect of antinuclear antibody positivity on antineutrophil cytoplasmic antibody results by indirect immunofluorescence assay.

The indirect immunofluorescence assay (IIFA) utilizing antineutrophil cytoplasmic antibodies (ANCA) is widely used as a diagnostic test for autoimmune vasculitis. The presence of antinuclear antibodies (ANA) might lead to a misleading interpretation of ANCA. This study aims to explore the impact of the presence of ANA on the interpretation of ANCA. This retrospective research examined samples negative for antiMPO and antiPR3 ANCA by IIFA and explored correlations between the ANA-IIFA results and the ANCA interpretation frequencies. Our analysis involved the use of suitable statistical methods, including Chi-square and kappa statistics. Up to 75.2% of the ANCA-IIFA-positive samples exhibited a positive p-ANCA pattern when using the ethanol-fixed substrate, with c-ANCA positivity at 24.8%. In the ANA-IIFA-positive samples, ~77.3% displayed p-ANCA patterns on ethanol-fixed substrates. A comparison between the ANA-IIFA titers and the p-ANCA results revealed that p-ANCA positivity was notably more common in samples with higher titers, and this correlation was found to be statistically significant. Positive ANA results by IIFA tests are linked to a higher incidence of p-ANCA interpretation, particularly in cases with higher titer patterns. This insight aids laboratories in establishing effective workflows to investigate potential p-ANCA interference.

Analysis of Antinuclear Antibody Test Referral Patterns in a Tertiary Care Hospital over Three Years: A Retrospective Observational Study

Introduction: Antinuclear Antibodies (ANA) detection by Human Epithelial Substrate (Hep2) is the recommended screening test for the diagnosis of ANA-Associated Rheumatic Diseases (AARD). ANA is ordered by various specialists in a tertiary care hospital, and a positive ANA result is followed by testing for specific autoantibodies. High pretest probability, pattern type with intensity, and referral departments are key factors determining the autoimmune diagnosis. Aim: To analyse the ANA referral patterns among the various departments and also to estimate the prevalence and clinical significance of rare ANA patterns. Materials and Methods: A retrospective observational study was conducted at Nizam's Institute of Medical Sciences, Hyderabad, a tertiary care hospital, in Hyderabad, Telangana, India where ANA test reports (n=16,994) from various departments over three years (November 2017 to October 2020) were evaluated between November 2022 to December 2022. ANA tests were performed on Hep2 substrate at a 1:100 dilution, and ANA patterns were reported according to the International Consensus on ANA Patterns (ICAP) nomenclature. Statistical analysis of department- wise ANA positivity and fluorescence intensity was conducted, and the final diagnoses of patients with rare ANA patterns (<1%) were noted from clinical records. Fischer's-exact test was used for comparing categorical variables, considering p-value <0.05 as statistically significant. Results: The majority of ANA requests were from the Rheumatology department (5859; 34.5%), followed by nephrology (3132; 18.4%), neurology (1940; 11.4%), general medicine (1646; 9.7%), haematology (1106; 6.5%), and casualty (878; 5.2%), accounting for 85.6% of total referrals. The highest percentage of positivity among ANA referrals was observed in Rheumatology (333; 5.7%), with 58% of positive ANA showing 4+ intensity. No positives were observed from many surgical departments. Rare ANA patterns with a prevalence of less than 1% were observed in 22 patients with mitotic patterns accounting for the majority of rare patterns seen in 11 out of 22 (50%) cases followed by nuclear envelope, rods rings, and nuclear dense fine speckled patterns were observed in six, four, and one patient(s), respectively. The majority of rare ANA patterns had 2+ fluorescence intensity without any associated autoimmune diagnosis. Conclusion: The highest and lowest positivity among ANA referrals were observed in the rheumatology and surgical departments, respectively. Considering the pretest probability of AARD before ordering an ANA test would lead to the optimum utilisation of laboratory services. Mitotic patterns constituted the majority of rare ANA patterns and need to be clinically correlated with antibody titers.

Brachio-cervical inflammatory myopathy associated with systemic sclerosis. Case series and review of literature.

This study was aimed at describing a case series of brachio-cervical inflammatory myopathy (BCIM) associated with systemic sclerosis (SSc), due to its rarity and limited coverage in published data. Another aim was to provide a literature review. We reported four cases of BCIM-SSc from our tertiary center. In addition, we researched the literature and found six articles featuring 17 patients who fit this phenotype. We pooled all cases and reported their features. Most patients were female and had limited SSc, and the median time of BCIM presentation was three years after SSc diagnosis. Asymmetric muscle involvement, scapular winging, dropped head, axial weakness, camptocormia, dysphagia, and dermatomyositis stigmas were common features. All patients had esophageal involvement. Most had positive antinuclear antibody results, a scleroderma pattern in their capillaroscopy images, elevated serum creatine phosphokinase, myopathic electrophysiology, and muscle involvement in magnetic resonance imaging. Muscle histopathological findings varied widely, but in general all showed the presence of lymphoid infiltrates, muscle atrophy, increased MHC-I expression, MAC deposits, vasculopathy, and muscle fiber necrosis. The response to immunosuppressive therapy was highly irregular. BCIM-SSc is a rare disorder that shares many similar phenotypes among the described cases, but has a highly heterogeneous response to treatment. At present, more data on the physiopathology, clinical features, and treatment is still needed.

Only monospecific anti-DFS70 antibodies aid in the exclusion of antinuclear antibody associated rheumatic diseases: an Italian experience.

Background The dense fine speckled (DFS) is one of the most common patterns that can be observed as a result of the anti-nuclear antibodies (ANA) test on HEp-2 cells and is mostly caused by antibodies to DFS70 as the main antigenic target. As was recently demonstrated, isolated anti-DFS70 positivity can be used as an aid in the exclusion of ANA associated rheumatic diseases (AARD) due to the opportunity to better interpret unexplained positive IIF ANA results. Methods Our study included 333 subjects with AARD, 51 undifferentiated connective tissue disease (UCTD) patients, 235 disease controls and 149 healthy blood donors from an Italian cohort. All samples were tested for anti-DFS70 and anti-ENA antibodies using QUANTA Flash assays (Inova Diagnostics, San Diego, CA, USA). Results No differences in the prevalence of anti-DFS70 antibodies were seen among AARD, non-AARD and UCTD (2.1% [7/333] vs. 2.3% [9/384] vs. 5.9% [3/51], respectively; p-value = 0.188). AARD patients positive for anti-DFS70 antibodies showed in all cases an accompanying anti-ENA specificity. In contrast, monospecific anti-DFS70 antibodies showed a significantly different distribution with a clear trend across the main groups (AARD vs. non-AARD vs. UCTD: 0% [0/7] vs. 22% [2/9] vs. 100% [3/3], p = 0.007). Anti-DFS70 antibody levels among AARD, non-AARD and UCTD patients were not significantly different (p = 0.094). Within the anti-DFS70 antibody positive cases, AARD cohort showed a higher variability (median [min-max]: 3.2 [3.2-450.8] CU) compared to non-AARD (median [min-max]: 3.2 [3.2-75.7] CU) and UCTD patients (median [min-max]: 3.2 [3.2-59.0] CU). Conclusions Our preliminary data showed a similar frequency of anti-DFS70 antibodies in AARD, UCTD and non-AARD cohorts. Monospecificity of anti-DFS70 antibodies but not their mere presence is the key element in the diagnostic algorithm. Mono-specific anti-DFS70 antibodies might be a helpful biomarker to discriminate individuals with AARD from non-AARD presenting with a positive ANA.

Antinuclear antibody testing in a Turkish pediatrics clinic: is it always necessary?

IntroductionThe term anti-nuclear antibody (ANA) is used to define a large group of autoantibodies which specifically bind to nuclear elements. Although healthy individuals may also have ANA positivity, the measurement of ANA is generally used in the diagnosis of autoimmune disorders. However, various studies have shown that ANA testing may be overused, especially in pediatrics clinics. Our aim was to investigate the reasons for antinuclear antibody (ANA) testing in the general pediatrics and pediatric rheumatology clinics of our hospital and to determine whether ANA testing was ordered appropriately by evaluating chief complaints and the ultimate diagnoses of these cases.MethodsThe medical records of pediatric patients in whom ANA testing was performed between January 2014 and June 2016 were retrospectively evaluated. Subjects were grouped according to the indication for ANA testing and ANA titers.ResultsANA tests were ordered in a total of 409 patients during the study period, with 113 positive ANA results. The ANA test was ordered mostly due to joint pain (50% of the study population). There was an increased likelihood of autoimmune rheumatic diseases (ARDs) with higher ANA titer. The positive predictive value of an ANA test was 16% for any connective tissue disease and 13% for lupus in the pediatric setting.Conclusionin the current study, more than one-fourth of the subjects were found to have ANA positivity, while only 15% were ultimately diagnosed with ARDs. Our findings underline the importance of an increased awareness of correct indications for ANA testing.

Detection of antinuclear antibody in autoimmune connective tissue diseases: a comparison between immunofluorescence and solid-phase assay

Background Testing for antinuclear antibodies (ANA) is useful for the diagnosis of autoimmune connective tissue diseases (CTD). Solid-phase assay such as the enzyme-linked immunosorbent (ELISA) assay has replaced the use of indirect immunofluorescence assay (IIF) for the detection of ANA. Patients and methods In this study, ELISA which is based on a qualitative screening of IgG class autoantibodies using commercially available kits from Orgetec Diagnostika GmbH was compared with IIF for the detection of ANA in patients with different connective tissue diseases. The study involved 73 patients with confirmed diagnosis (38 patients diagnosed as systemic lupus erythematosus (SLE), 27 patients with rheumatoid arthritis (RA), and eight patients with other connective tissue diseases: systemic sclerosis, mixed connective tissue diseases, and Sjogren’s syndrome). They were recruited from the outpatient clinic of the Rheumatology and Rehabilitation Department for follow-up and others were admitted patients of the Rheumatology Department at Assuit University Hospitals. Twenty-five apparently healthy participants served as the control group. Results ANA results by IIF: of the 73 patients, 39 (53.4%) had positive ANA results and 34 (46.6%) patients had negative ANA results. All healthy control group ANA results by IIF were negative (100%). ANA results by ELISA: from a total of 73 patients, 42 (57.5%) had positive ANA results, 27 (37%) patients had negative ANA results, and four (5.5%) patients had borderline ANA results. All control group ANA results by ELISA had negative ANA results. ELISA sensitivity was 86.8% compared with 84.2% by IIF in the SLE. In other CTD both tests had the same sensitivity (87.5%). The ELISA and IIF had the same high specificity (100%) in SLE and other CTD. Conclusion There is a comparable result between sensitivity, specificity, PPV, NPV, and accuracy of both ANA tests. So we can rely on the results of ELISA in our laboratories in Assuit University Hospitals as they can deal with large numbers of patients and it saves time. IIF is partly subjective, and therefore there is considerable variation in the interpretation of results between different observers, so we can avoid it. So ANA by ELISA tests can be used as a screening test and if we want to identify the ANA pattern we can use IIF on HEp-2 cells.

Antinuclear antibody testing in obstetric patients.

To assess possible associations between the presence of antinuclear antibodies (ANAs) and pregnancy outcome in order to determine the significance of this test in obstetric practice. A case-control study was performed on 408 patients admitted to an obstetric high care unit and on whom ANA testing was consecutively performed. The study group consisted of 46 patients who tested positive for ANAs and a control group of 92 patients who tested negative for ANAs. In addition to demographic data, indications for admission and pregnancy outcome were compared between the two groups. Of the 46 patients with a positive ANA result, 28 had an antinuclear pattern, 13 an anticytoplasmic pattern and 5 an antinuclear and an anticytoplasmic pattern. No significant differences were observed between the two groups (ANA-positive and negative) with regard to demographic data, indication for admission, clinical and laboratory data, and pregnancy outcome. The patients were also tested for anticardiolipin antibodies, and significantly more patients with severe pre-eclampsia tested positive (24% versus 4.7%, p = 0.01). No difference in HIV status and presence of autoantibodies was found between the two groups. The presence of ANAs was not associated with adverse pregnancy outcome. Therefore routine patient testing for ANAs in an obstetric high-care unit is not recommended.

Use of antipolymer antibody assay in recipients of silicone breast implants

Local complications (encapsulation, rashes, rupture, and leakage) can occur after placement of silicone gel-containing breast implants (SBI). Whether SBI exposure results in systemic manifestations in some recipients is controversial. We have carried out a blinded study to assess whether there is any difference between SBI recipients and non-exposed controls in the proportions positive for serum antibodies directed against polymeric substances. We recruited female SBI recipients (including those without symptoms) who presented to a single rheumatology clinic. A physician global assessment was used to classify SBI recipients who did not meet criteria for specific autoimmune diseases according to the severity of local and systemic signs and symptoms. Controls were recruited from among clinic staff and their acquaintances. Results of the antipolymer antibody (APA) assay were compared with those of an assay for antinuclear antibodies (ANA) and with the severity of the signs and symptoms. Positive APA results were found in one (3%) of 34 SBI recipients with limited symptoms, two (8%) of 26 with mild symptoms, seven (44%) of 16 with moderate symptoms, and 13 (68%) of 19 with advanced symptoms. Four (17%) of 23 healthy non-SBI-exposed controls and two (10%) of 20 non-exposed women with classic autoimmune diseases were positive for APA. Thus, women with moderate or advanced symptoms were significantly more likely than those with limited or mild symptoms, or non-exposed controls to have APA (p < 0.001). The proportion with positive ANA results was higher for women with classic autoimmune diseases 14 (70%) of 20 than for any SBI-exposed subgroup (0-33%). The APA assay can objectively contribute to distinguishing between SBI recipients with limited or mild signs and symptoms. SBI recipients with more severe manifestations, and patients with specific autoimmune diseases. Further studies will be needed to define the signs and symptoms associated with exposure to SBI.

Flow cytometric analyses of the lymphocyte subsets in peripheral blood of children with untreated active juvenile dermatomyositis

Juvenile dermatomyositis (JDMS) is a vasculopathy affecting primarily skin and muscle. Although the etiology is unknown, immunopathogenetic mechanisms appear to play a role in both the susceptibility to the disease and its progression. We measured the percentage and absolute numbers of B cells and T-cell subsets in the peripheral blood of untreated JDMS patients with active early disease and compared the results with those obtained from a study of peripheral blood obtained from a heatlhy age-related control group. The absolute number of total lymphocytes in the peripheral blood of the JDMS patients was significantly lower (P < 0.002) than that observed in the healthy control population, with an associated decrease in the absolute number of all T-cell subsets. No concomitant decrease in the absolute number of B lymphocytes was observed in the JDMS patients. In contrast, the percentage of B lymphocytes and the T-helper/T-suppressor cell ratio were significantly higher in the JDMS group than in the control group (P < 0.001 and P < 0.002, respectively). Retrospective analysis of JDMS patients' serum samples obtained within 1 month of the flow cytometric evaluation indicated that 79% of the sera contained an antinuclear antibody and 46% had immunoglobulin G values above age-adjusted reference ranges. The increased percentage of B cells, the increased T-helper/T-suppressor cell ratio, the positive antinuclear antibody results, and the increased concentration of serum immunoglobulin suggest that humoral immune dysregulation may contribute to the pathogenesis of JDMS.

Autoantibodies in patients with primary pulmonary hypertension: Association with anti-Ku

purpose: Patients with primary pulmonary hypertension (PPH) frequently have Raynaud's phenomenon, serum antinuclear antibodies (ANAs), and/or pulmonary vascular lesions similar to those seen in certain connective tissue diseases, especially scleroderma. A number of relatively disease-specific autoantibodies have been described in connective tissue diseases but have not been studied in patients with PPH. Therefore, sera from PPH patients were studied for a variety of autoantibodies, seeking a possible link between this pulmonary disorder and connective tissue diseases. patients and methods: Sera from 31 patients with PPH and 24 with secondary pulmonary hypertension (SPH) were studied for the following autoantibodies: anti-centromere (indirect immunofluorescence of Hep-2 cells), anti-CENP-B by immunoblotting and enzyme immunoassay (EIA) using cloned CENP-B fusion protein, anti-topoisomerase I (Scl-70), anti-Ku using immunoblotting of affinity purified antigens, anti-cardiolipin using EIA, and anti-Ro (SS-A), La (SS-B), Sm, nRNP, Jo-1, PM-Scl, and Mi-2 by counter-current immunoelectrophoresis. results: Anti-Ku antibodies were found in 23% of patients with PPH, 4% with SPH, and none of 24 normal controls (PPH versus SPH, p = 0.06; PPH versus controls, p = 0.01). Antibodies to CENP-B were found in one patient each with PPH and SPH, anti-topoisomerase I in one with SPH, and anti-Ro (SS-A) and La (SS-B) in one with PPH. Overall, 12 patients (39%) with PPH had Raynaud's phenomenon or positive ANA results, with 9 (29%) having more specific auto-antibodies associated with connective tissue diseases. conclusions: These results further suggest a link between at least a subgroup of patients with PPH and autoimmune connective tissue diseases, with anti-Ku antibodies being a possible new serologic marker.

Anti-Ro/SSA Antibodies

• Twenty-one patients with clinical and histopathologic evidence of subacute cutaneous lupus erythematosus and one patient with Sjogren's syndrome and vasculitis had anti-Ro/SSA (Sjogren's syndrome A) antibodies as demonstrated by double immunodiffusion assay using a saline extract of human spleen as the source of antigen. These serum samples were negative when tested for other nuclear antigens, including native DNA, Sm, and RNP. When tested for antinuclear antibodies (ANAs) by immunofluorescence, only ten of 22 serum samples were ANA positive on mouse liver substrate, while 18 of 22 had a positive ANA when HEp-2 tumor cells were utilized. With imprints of human spleen as test substrate, all 22 serum samples yielded a positive ANA result and a particulate (large speckledlike thread) staining pattern. Absorption of two of these serum samples with human spleen extract containing Ro/SSA antigen inhibited both the particulate staining pattern using human spleen imprints and the anti-Ro/SSA precipitin line by double immunodiffusion. These studies suggest that anti-Ro/SSA antibodies and antibodies producing the particulate nuclear staining pattern on human spleen imprints are either one and the same or closely paralleling antibody systems. ( Arch Dermatol 1985;121:335-338)

Anti-Ro/SSA antibodies. Association with a particulate (large speckledlike thread) immunofluorescent nuclear staining pattern

Twenty-one patients with clinical and histopathologic evidence of subacute cutaneous lupus erythematosus and one patient with Sjögren's syndrome and vasculitis had anti-Ro/SSA (Sjögren's syndrome A) antibodies as demonstrated by double immunodiffusion assay using a saline extract of human spleen as the source of antigen. These serum samples were negative when tested for other nuclear antigens, including native DNA, Sm, and RNP. When tested for antinuclear antibodies (ANAs) by immunofluorescence, only ten of 22 serum samples were ANA positive on mouse liver substrate, while 18 of 22 had a positive ANA when HEp-2 tumor cells were utilized. With imprints of human spleen as test substrate, all 22 serum samples yielded a positive ANA result and a particulate (large speckledlike thread) staining pattern. Absorption of two of these serum samples with human spleen extract containing Ro/SSA antigen inhibited both the particulate staining pattern using human spleen imprints and the anti-Ro/SSA precipitin line by double immunodiffusion. These studies suggest that anti-Ro/SSA antibodies and antibodies producing the particulate nuclear staining pattern on human spleen imprints are either one and the same or closely paralleling antibody systems.

Triad of glomerulonephritis, antinuclear antibodies, and positive skin immunofluorescence: Variant of systemic lupus erythematosus

We are reporting findings in 13 patients who presented with glomerulonephritis without evidence of systemic disease, but who were found to have positive antinuclear antibody results and immunoglobulin and/or complement deposits at the dermal-epidermal junction of normal skin not exposed to light. There was no evidence of other organ involvement, and serologic tests for systemic lupus erythematosus (SLE) gave negative results. The renal disease is characterized by severe proteinuria, focal or diffuse proliferative glomerular lesions on biopsy, with variable patterns of immunoglobulin deposits. No clinical manifestations or serologic results typical of SLE have developed during prolonged observation. HLA phenotyping carried out in eight of the 13 patients revealed DR2 or DR3 alloantigens or both in seven of the eight patients, an incidence similar to that in patients with overt SLE. Because of the specificity of the skin biopsy immunofluorescence, the similarity of HLA-DR antigens, and a favorable response of the renal disease to therapy, we believe that these patients have a variant of SLE.