Rheumatoid Factor

What the laboratory says this test is for

This panel can be helpful in the diagnosis of Sjogren syndrome by simultaneously testing for antinuclear antibodies (ANAs) with an immunofluorescence assay (IFA), performed on human epithelial type 2 (HEp-2) cells, as well as SSA antibodies, SSB antibodies, rheumatoid factor (RF), thyroid peroxidase (TPO) antibodies, and anti-mitochondrial antibodies (AMAs). For specimens with positive ANA IFA results, reflex testing for ANA titer and pattern is performed. For specimens with positive AMA results, reflex testing for AMA titer is performed.The laboratory evaluation for individuals with clinical suspicion of autoimmune diseases often begins with an ANA screen. The classic ANA IFA on HEp-2 cells is considered by the American College of Rheumatology (ACR) as the current gold standard because of its overall high sensitivity for several autoimmune diseases [1]. Knowing the ANA titer and fluorescent staining pattern can be helpful in interpreting positive results [2]. Individuals with negative results on the ANA IFA usually also have negative results on specific autoantibodies. However, SSA antibody may be detected in some ANA IFA-negative patients with lupus or Sjogren syndrome [3].The 2012 ACR classification criteria for Sjogren syndrome indicate that testing for SSA or SSB antibody has the highest sensitivity and specificity, and that a positive RF result in addition to an ANA titer ≥1:320 is consistent with Sjogren syndrome [4]. However, the 2016 ACR/European League Against Rheumatism (EULAR) classification criteria for Sjogren syndrome do not include SSB/La, RF, and ANA titer, because studies showed that these markers do not add sufficient value to SSA/Ro testing [5].Primary Sjogren syndrome is associated with an increased frequency of certain other autoimmune diseases [6]. Detecting characteristic markers, such as AMAs for primary biliary cholangitis and TPO antibodies for autoimmune thyroid disease, may aid in the evaluation of coexisting autoimmune diseases.The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.References1. Methodology of testing for antinuclear antibodies (position statement). 2009. American College of Rheumatology. Updated December 2019. Accessed May 15, 2023. https://assets.contentstack.io/v3/assets/bltee37abb6b278ab2c/blta48818378bc89445/acr-position-statement-methodology-testing-antinuclear-antibodies.pdf2. Tozzoli R, et al. Am J Clin Pathol. 2002;117(2):316-324.3. Yazdany J, et al. Arthritis Care Res (Hoboken). 2013;65(3):329-339.4. Shiboski SC, Arthritis Care Res (Hoboken). 2012;64(4):475-487.5. Shiboski CH, et al. Ann Rheum Dis. 2017;76(1):9-16.6. St. Clair EW, et al. Sjogren's Syndrome. In: Firestein GS, et al, eds. Kelley & Firestein's Textbook of Rheumatology. 10th ed. Elsevier; 2017.

What the laboratory says this test is for

About 10-30% of patients continue with lingering symptoms four or more weeks after COVID-19 infection, including those who had mild, or no symptoms termed as post-COVID conditions. The Centers for Disease Control (CDC) provided Interim Guidance for Assessment and Testing for Evaluating and Caring for Patients with Post-COVID Conditions. The CDC recommends laboratory testing be guided by the patient history, physical examination, and clinical findings. Specialized tests might be considered if symptoms persist for 12 weeks post COVID. This panel is to be considered for persistent symptoms such as joint pains or rheumatological conditions.

What the laboratory says this test is for

A subset of interstitial lung disease (ILD) patients have underlying connective tissue diseases (CTDs). This panel serves as an aid for the diagnosis of CTDs, including rheumatoid arthritis, inflammatory myositis, systemic sclerosis, and Sjogren’s syndrome, that are associated with the development of ILD. If left untreated, these CTD patients may develop lung fibrosis and inflammation. ILD is a direct consequence of these pathological changes. When severe, ILD leads to restrictive lung disease, pulmonary arterial hypertension, and cardiac disease (cor pulmonale).

What the laboratory says this test is for

This panel can be helpful in the diagnosis of autoimmune rheumatic diseases, including systemic lupus erythematosus, systemic sclerosis, Sjogren syndrome, mixed connective tissue disease, and rheumatoid arthritis. All specimens are screened for antinuclear antibodies (ANAs) with multiplex immunoassay. This approach simultaneously detects antibodies to dsDNA, chromatin, ribosomal protein, SSA, SSB, Smith (Sm), Sm/RNP, RNP, Scl-70, Jo-1, and centromere B. A positive result indicates the presence of at least 1 of these antibodies; a negative result indicates that none of the component antibodies were detected. Regardless of the result, this panel also detects antibodies to dsDNA, Sm, Sm/RNP, Scl-70, SSA and SSB as well as rheumatoid factor.ANA immunofluorescence assay (IFA) on HEp-2 cells is considered by the American College of Rheumatology as the current gold standard for ANA screening because of its overall high sensitivity for several autoimmune diseases [1]. However, because patients with other diseases and healthy individuals may be positive for ANA IFA, using immunoassays for screening may be more specific for a systemic rheumatic disorder [2]. On the other hand, multiplex immunoassay screening cannot rule out autoimmune diseases characterized by other antibodies, such as autoimmune hepatitis and primary biliary cholangitis, which may be positive for ANA IFA.The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.⁠⁠⁠⁠⁠⁠⁠References1. Methodology of testing for antinuclear antibodies (position statement). 2009. American College of Rheumatology. Updated December 2019. Accessed May 15, 2023. https://assets.contentstack.io/v3/assets/bltee37abb6b278ab2c/blta48818378bc89445/acr-position-statement-methodology-testing-antinuclear-antibodies.pdf2. Fritzler MJ, et al. J Appl Lab Med. 2022;7:357-361.

What the laboratory says this test is for

This panel can be helpful in the diagnosis of systemic lupus erythematosus (SLE) and several other autoimmune diseases, including mixed connective tissue disease, Sjogren syndrome, systemic sclerosis, and autoimmune thyroid disease. The panel simultaneously tests for antinuclear antibodies (ANAs) with an immunofluorescence assay (IFA), performed on human epithelial type 2 (HEp-2) cells, and 11 biomarkers associated with these conditions. For specimens with positive ANA IFA results, reflex testing for ANA titer and pattern is performed.The ANA testing has high sensitivity (97%) for SLE but limited specificity (34%) [1]. Thus, a positive ANA test does not exclude other autoimmune diseases with similar clinical features [2]. Testing for specific antibodies in a panel may expedite the evaluation of SLE but is generally not recommended [3].The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.References1. Petri M, et al. Arthritis Rheum. 2012;64(8):2677-2686.2. Kavanaugh A, et al. Arch Pathol Lab Med. 2000;124(1):71-81.3. Yazdany J, et al. Arthritis Care Res (Hoboken). 2013;65(3):329-339.

What the laboratory says this test is for

Sensory-motor neuropathies may occur by various mechanisms. These include development of autoantibodies to neuronal structures such as myelin associated glycoprotein (MAG) antibody, Hu antibody, and the ganglioside antibodies. Sensory-motor neuropathies may also occur via antibody cross-reactivity or local immune complex deposition as seen in autoimmune disease with primarily non-neuronal targets including Sjogren's syndrome (SSA/SSB), systemic lupus erythematosus and related conditions (ANA IFA), celiac disease (tTG antibody), vasculitis (ANCA), and immune complex deposition (cryoglobulins, rheumatoid factor). Motor-sensory neuropathy may be associated with monoclonal gammopathy (serum immunofixation and serum immunoglobulins).

What the laboratory says this test is for

This test can be helpful in the diagnosis of autoimmune rheumatic diseases. Specimens with positive results for antinuclear antibodies (ANA) by indirect immunofluorescence assay (IFA) are subsequently tested for a series of ANA-specific autoantibodies in cascade tiers. The first tier focuses on autoantibodies associated with systemic lupus erythematosus (SLE) and mixed connective tissue disease; the second tier detects autoantibodies seen in Sjogren syndrome, systemic sclerosis and polymyositis; and the third tier includes markers of the limited form of systemic sclerosis and neuropsychiatric SLE. This screen also includes the following markers of rheumatoid arthritis: rheumatoid factor, anti-cyclic citrullinated peptide antibody and anti-mutated citrullinated vimentin antibody.Note that the cascade stops with the first tier in which a positive antibody result is observed. Therefore, even if an antibody included in a subsequent tier is present, it will not be reported with this test. If the ANA IFA result is positive but all the specific autoantibodies tested in the cascade antibody tests are negative, the patient may still have an autoimmune disease other than those typically associated with the antibodies tested.

What the laboratory says this test is for

Autoantibody testing has a major role in the diagnosis of RA. This panel includes Rheumatoid factor (RF), anti-cyclic citrullinated peptide (CCP) and anti-mutated citrullinated vimentin (MCV). RF is found in a majority of patients with RA but is not specific for the diagnosis. Anti-CCP antibody is more sensitive and highly specific. RF and anti-CCP are included in the most recent classification criteria for RA. The past several years have seen a search for biomarkers which might increase sensitivity in order to identify the minority of RA patients who are negative for either RF or CCP, especially early in the course of disease. The addition of anti-MCV increases sensitivity for RA when tested together with RF and CCP.

What the laboratory says this test is for

This panel can be helpful in the diagnosis of autoimmune diseases with a focus on rheumatoid arthritis (RA) by simultaneously testing for antinuclear antibodies (ANAs) with an immunofluorescence assay (IFA), performed on human epithelial type 2 (HEp-2) cells, as well as the RA markers rheumatoid factor (RF) and cyclic citrullinated peptide (CCP) antibody (IgG). For specimens with positive ANA IFA results, reflex testing for ANA titer and pattern is performed.The laboratory evaluation for individuals with clinical suspicion of autoimmune diseases often begins with an ANA screen. The classic ANA IFA on HEp-2 cells is considered by the American College of Rheumatology (ACR) as the current gold standard because of its overall high sensitivity for several autoimmune diseases [1]. Although RA is not generally associated with ANA, occasional patients may present with features of RA and SLE ("rhupus") and be positive for ANA and RA markers [2].This panel includes RF and CCP IgG antibody, 2 widely used laboratory markers that are included in the ACR/ European League Against Rheumatism classification (EULAR) criteria for RA [3]. The combination of RF and CCP antibody provides greater sensitivity than either assay alone [4] and is commonly used in the diagnostic evaluation of suspected RA.The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.References1. Methodology of testing for antinuclear antibodies (position statement). 2009. American College of Rheumatology. Updated December 2019. Accessed May 15, 2023. https://assets.contentstack.io/v3/assets/bltee37abb6b278ab2c/blta48818378bc89445/acr-position-statement-methodology-testing-antinuclear-antibodies.pdf2. Antonini L, et al. Autoimmun Rev. 2020;19(9):102612.3. Aletaha D, et al. Arthritis Rheum. 2010;62(9):2569-2581.4. Maksymowych WP, et al. J Rheumatol. 2014;41(11):2104-2113.

What the laboratory says this test is for

This panel can be helpful in the diagnosis of Sjogren syndrome by simultaneously testing for antinuclear antibodies (ANAs) with an immunofluorescence assay (IFA), performed on human epithelial type 2 (HEp-2) cells, as well as SSA antibodies, SSB antibodies, and rheumatoid factor (RF). For specimens with positive ANA IFA results, reflex testing for ANA titer and pattern is performed.The laboratory evaluation for individuals with clinical suspicion of autoimmune diseases often begins with an ANA screen. The classic ANA IFA on HEp-2 cells is considered by the American College of Rheumatology (ACR) as the current gold standard because of its overall high sensitivity for several autoimmune diseases [1]. Knowing the ANA titer and pattern can be helpful in interpreting positive ANA results [2]. Individuals with negative results on the ANA IFA usually also have negative results on specific autoantibodies. However, SSA antibody may be detected in some ANA IFA-negative patients with lupus or Sjogren syndrome [3].The 2012 ACR classification criteria for Sjogren syndrome indicate that testing for SSA or SSB antibody has the highest sensitivity and specificity, and that a positive RF result in addition to an ANA titer ≥1:320 is consistent with Sjogren syndrome [4]. However, the 2016 ACR/European League Against Rheumatism (EULAR) classification criteria for Sjogren syndrome do not include SSB/La, RF, and ANA titer, because studies showed that these markers do not add sufficient value to SSA/Ro testing [5].The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.References1. Methodology of testing for antinuclear antibodies (position statement). 2009. American College of Rheumatology. Updated December 2019. Accessed May 15, 2023. https://assets.contentstack.io/v3/assets/bltee37abb6b278ab2c/blta48818378bc89445/acr-position-statement-methodology-testing-antinuclear-antibodies.pdf2. Tozzoli R, et al. Am J Clin Pathol. 2002;117(2):316-324.3. Yazdany J, et al. Arthritis Care Res (Hoboken). 2013;65(3):329-339.4. Shiboski SC, Arthritis Care Res (Hoboken). 2012;64(4):475-487.5. Shiboski CH, et al. Ann Rheum Dis. 2017;76(1):9-16.

What the laboratory says this test is for

The combination of RF and anti-CCP antibodies provide greater specificity for the diagnosis of Rheumatoid Arthritis (RA). CCP antibodies may be present earlier than RF and often indicate increased erosive disease in RA.

What the laboratory says this test is for

Elevated RF is found in collagen vascular diseases such as SLE, rheumatoid arthritis, scleroderma, Sjogren's syndrome, and in other conditions such as leprosy, tuberculosis, syphilis, malignancy, thyroid disease and in a significant percentage of otherwise normal elderly patients.