Nuclear Dense Fine Speckled Pattern Research Articles

The clinical characteristics of nuclear dense fine speckled pattern in 95 289 patients

To investigate the distribution and clinical significance of nuclear dense fine speckled (DFS) pattern in various diseases. A total of 95 289 patients who received DFS tests at Peking Union Medical College Hospital from January 2019 to December 2020 were included in this study. The results of indirect immunofluorescence assay (IIF) for detection of antinuclear antibody (ANA) were evaluated. The positive rates of ANA and DFS were 39.60% (37 733/95 289) and 1.19% (1 139/95 289) respectively. The positive rate of DFS in ANA-positive patients was 3.02% (1 139/37 733). DFS and ANA positivity were significantly different among different age groups rather than gender. The positivity rate of DFS reached the peak (55.57%, 633/1 139) in young patients between 21-40 years, while positive ANA with negative DFS was mainly observed in patients between 41-60 years (37.26%, 13 636/36 594). Additionally, single ANA-positivity were mainly detected in rheumatology department (59.23%, 18 402/31 066), whereas positive DFS was more common in obstetrics and gynecology department (3.08%, 49/1 593). There were 82.88% (944/1 139) patients with positive DFS diagnosed with non-autoimmune disease (non-AID), and 19.49%(222/1 139) with dermatosis. Positive DFS with higher titer (≥1∶320) was detected more frequently in autoimmune disease (AID) patients (5.13%, 10/195) than in non-AID patients (1.69%, 16/944) (P<0.05). The DFS pattern is rare in ANA positive patients, which is mainly observed in women between 21-49 years. High titer of DFS is prevalent in AID patients, but positive DFS is detected more in non-AID patients, especially those with dermatosis.

Distinctive features of positive anti-cell antibody tests (indirect immunofluorescence on HEp-2 cells) in patients with non-autoimmune diseases.

The objective of this study was to determine whether characteristics of positive results in the indirect immunofluorescence assay on HEp-2 cells for anti-cell antibodies (HEp-2 IFA) differ between patients with non-autoimmune diseases (NADs) and patients with systemic autoimmune rheumatic diseases (SARDs). Cross-sectional observational study comparing HEp-2 IFA test results in three groups: (a) 558 NAD patients comprising four subgroups (cancer ( n = 95), infectious diseases ( n = 148), psychiatric diseases ( n = 163), common non-infectious chronic diseases ( n = 152)); (b) 194 SARD patients; (c) 1217 healthy individuals (HIs). Sera were tested at 1:80 dilution and diluted to the end titer. Slides were analyzed by two independent blinded examiners. A positive HEp-2 IFA test occurred in 102 (18.3%) NAD patients, 170 (87.6%) SARD patients and 150 (12.3%) HIs. The four NAD subgroups did not differ regarding HEp-2 IFA frequency, titer or pattern. HEp-2 IFA titer was higher in NAD patients than in HIs and both had lower titer than SARD patients. Nuclear dense fine speckled pattern was more frequent in NAD patients and HIs than in SARD patients ( p < 0.001). Nuclear homogeneous and nuclear coarse speckled patterns were more frequent in SARD patients than in the other groups ( p < 0.001). The nuclear fine speckled pattern was prevalent in all three groups, but presented a gradient in titer across them; HIs and NAD patients had low and intermediary titers, which were significantly lower than in SARD patients ( p < 0.001). Positive HEp-2 IFA frequency, pattern and titer present differential features in NAD and SARD patients, and this attribute adds value to the test in the diagnosis of SARDs.

The antinuclear antibody test: Last or lasting gasp?

Autoantibodies have been regarded as a serologic hallmark of systemic autoimmune rheumatic diseases (ARDs) for more than half a century. Two years following the landmark discovery of the lupus erythematosus (LE) cell and the LE cell phenomenon by Hargraves and colleagues at the Mayo Clinic in 1948 (1), Coons and Kaplan described indirect immunofluorescence (IIF) as a useful approach to the detection of serum autoantibodies directed against intracellular antigens (2). This led to IIF applications designed to detect antinuclear antibodies (ANAs) as a key approach to the laboratory diagnosis of systemic lupus erythematosus (SLE) and eventually other systemic ARDs (3). After more than 50 years of widespread use, the ANA test and other IIF applications have enjoyed a favored position in diagnostic medicine, although they have been plagued by limitations and are now being challenged by newer diagnostic platforms and technologies (4). The advent and acceptance of the newer technologies has also been predicated on the appreciation that the ANA IIF test is not well suited to high-volume and high-throughput laboratories where the containment of medical health care costs has been a determining factor. Nevertheless, it has been recognized that many of these high-throughput technologies have limitations, most notably falsenegative results, in the detection of ANAs (5). To address these issues and concerns, the American College of Rheumatology (ACR) convened a committee to undertake an analysis and provide recommendations with respect to ANA testing as an approach to diagnosing systemic ARDs. In May 2010, a summary of the committee’s findings and recommendations was published; among these was the recommendation that the ANA IIF test using cell substrates should be considered the “gold standard” assay to screen for autoantibodies in sera from patients with systemic ARDs (5). For several decades, it has been well known that the ANA IIF test is compromised by the lack of universal standardization and by false-positive tests that lead (in some clinicians’ opinions) to “unnecessary” referrals or even to inappropriate diagnoses. An interesting case in point are autoantibodies that produce a staining pattern referred to as nuclear dense fine speckled, and in this issue of Arthritis & Rheumatism, Mariz and colleagues elaborate on the nuclear dense fine speckled pattern and provide timely and provocative observations about its usefulness as a screening test for systemic ARDs (6). However, unlike the case with other ANAs, Mariz et al suggest that the detection of the nuclear dense fine speckled staining pattern can be used as a biomarker to rule out the diagnosis of SLE and/or other systemic ARDs. Two key points need to be made: first, it should not be concluded that all sera demonstrating the nuclear dense fine speckled staining pattern are from healthy individuals; second, before the observations and conclusions reached by Mariz and colleagues can be widely accepted and applied in clinics, a number of issues should be addressed.

Pattern on the antinuclear antibody–HEp‐2 test is a critical parameter for discriminating antinuclear antibody–positive healthy individuals and patients with autoimmune rheumatic diseases

To identify features of antinuclear antibody (ANA)-HEp-2 test results that discriminate ANA-positive healthy individuals and patients with autoimmune rheumatic diseases (ARDs). We sequentially retrieved data on 918 healthy individuals and 153 patients with ARDs after clinical assessment. ANA-positive healthy individuals for whom data were available were reevaluated after 3.6-5.0 years. An ANA-HEp-2 test result was considered positive when a clear ANA pattern was observed at 1:80 dilution in 2 distinct commercial HEp-2 slides by 2 blinded independent observers. ANAs were present in 118 healthy individuals (12.9%) and 138 patients with ARDs (90.2%). The ANA titer was higher in patients with ARDs than in healthy individuals (P<0.001). The ANA pattern profile was distinct in the 2 groups. Nuclear homogeneous, nuclear coarse speckled, and nuclear centromeric patterns appeared exclusively in patients with ARDs. The nuclear dense fine speckled pattern occurred only in healthy individuals. The most frequent ANA pattern in both groups was the nuclear fine speckled pattern, which occurred at lower titer in healthy individuals than in patients with ARDs (P<0.001). Anti-extractable nuclear antigen was present in 1 healthy individual (anti-SSA/Ro) and in 52 patients with ARDs (37.7%). None of the 40 reevaluated healthy individuals developed ARDs, and 29 (72.5%) remained ANA positive. All healthy individuals who became ANA negative had an ANA titer of 1:80 at baseline. Our findings suggest that the titer, and especially the pattern, on the ANA-HEp-2 test strongly enhances our ability to discriminate ANA-positive healthy individuals and patients with ARDs.

Importância do padrão de fluorescência na interpretação do teste do FAN: o caso do padrão pontilhado fino denso

Determination of autoantibodies against cellular antigens (ANA-HEp-2) has undergone several methodological changes over the decades and for an appropriate evaluation of results requires reflection on its sensitivity and specificity properties. Currently the test is known to have high sensitivity and questionable specificity since it is frequently positive in a considerable number of non-autoimmune subjects. Awareness that a substantial portion of the population has a positive ANA-HEp-2 test demands that characteristics permitting to distinguish positive tests in autoimmune patients from positive tests in non-autoimmune subjects be identified. Among these characteristics are noteworthy the titer and the fluorescence pattern. In particular, one must bear in mind that the fluorescence pattern results from recognition by autoantibodies of distinct cellular structures and, therefore, the fluorescence pattern provides a preliminary indication of possible autoantigens targeted by the sera being tested. An emblematic example is the nuclear dense fine speckled pattern. It was originally studied by Ochs and collaborators in 1994 in a restricted number of patients with interstitial cystitis. Further studies demonstrated its frequent occurrence in laboratory practice in individuals with diverse non-autoimmune clinical conditions. Indeed, this pattern is one of the most frequently observed in non-autoimmune patients with an ANA-HEp-2 positive reaction. The present review intends to provide elements allowing the clinician to perform a critical interpretation of results of an ANA-HE-2 test, including analysis of the titer and the fluorescence pattern.

Análise crítica do teste de anticorpos antinúcleo (FAn) na prática clínica

A pesquisa de anticorpos contra antígenos celulares, tradicionalmente denominada FAN (fator antinúcleo) ou FAN-HEp-2, tem apresentado contínua evolução que requer dos profissionais envolvidos uma acurada e constante revisão sobre os paradigmas que norteiam a interpretação dos resultados obtidos. Os avanços metodológicos ocasionaram expressivo aumento na sensibilidade do teste e conseqüente diminuição de sua especificidade. Isto se verifica pelo crescente número de exames positivos em indivíduos aparentemente hígidos. Este fato tem criado situações desconfortáveis e muitas vezes angustiantes, sendo necessário buscar elementos para auxiliar os profissionais envolvidos. Estudos criteriosos e a experiência têm nos ensinado que há características peculiares usualmente associadas aos auto-anticorpos observados em pacientes auto-imunes e em indivíduos não auto-imunes. A presente revisão fornece uma abordagem sobre os pontos importantes para a correta valorização dos achados do teste do FAN-HEp-2 e que possam auxiliar na identificação de pacientes com doenças auto-imunes. Discute-se a importância do título e do padrão de imunofluorescência na valorização de um teste positivo e no desdobramento da pesquisa de auto-anticorpos específicos. Indivíduos não auto-imunes usualmente apresentam FAN-HEp-2 em títulos baixos, enquanto pacientes auto-imunes, geralmente, títulos médios ou altos. Entretanto, observam-se freqüentes exceções em ambos os contextos. Os padrões de fluorescência nucleares pontilhado grosso e homogêneo quase sempre se associam a um contexto de auto-imunidade sistêmica. Por outro lado, o padrão nuclear pontilhado fino denso é um dos mais freqüentemente observados em pessoas não auto-imunes com exame positivo de FAN-HEp-2. O Consenso Nacional para Padronização dos Laudos de FAN-HEp-2 tem desempenhado importante papel na melhoria da interpretação do exame de FAN-HEp-2 em nosso país. Finalmente, há que se considerar os possíveis e diversos significados de um teste positivo de FAN-HEp-2 em um paciente sem evidência objetiva de doença auto-imune.