{"id":4472,"date":"2026-09-22T15:58:56","date_gmt":"2026-09-22T22:58:56","guid":{"rendered":"https:\/\/www.ultalabtests.com\/blog\/?p=4472"},"modified":"2026-09-22T15:58:59","modified_gmt":"2026-09-22T22:58:59","slug":"tests-before-biologics-rheumatoid-arthritis","status":"publish","type":"post","link":"https:\/\/www.ultalabtests.com\/blog\/arthritis\/rheumatoid-arthritis\/tests-before-biologics-rheumatoid-arthritis\/","title":{"rendered":"Tests Before Biologics for Rheumatoid Arthritis (RA): TB and Hepatitis Screening"},"content":{"rendered":"\n
\"Torso
TB and hepatitis screening address infection-related questions before selected treatments. Results need to be reviewed with symptoms, exposure history, and the planned medicine.<\/figcaption><\/figure>\n\n\n\n

Before certain rheumatoid arthritis treatments begin, infection screening helps the care team plan safer treatment.<\/strong> Someone can feel well and still have evidence of a past infection that matters when the immune system is altered. Screening is therefore a preparation step, not an assumption that you are currently ill.<\/p>\n\n\n\n

This article explains tuberculosis and hepatitis testing before a biologic. Our rheumatoid arthritis blood-testing guide<\/a> provides the overall treatment-monitoring framework, and our infectious-disease testing guide<\/a> explains broader screening principles.<\/p>\n\n\n\n

Why infection history matters before treatment<\/h2>\n\n\n\n

Biologic medicines target parts of the immune system involved in inflammation. Some treatments can increase the likelihood that an infection becomes active or more serious. The risk differs by medicine, previous infections, exposure history, and other treatments.<\/p>\n\n\n\n

For example, the American College of Rheumatology's infliximab information<\/a> recommends tuberculosis and hepatitis testing before treatment. Other medicines have their own requirements. Targeted synthetic medicines, such as JAK inhibitors, are not biologics, but they may also require infection screening.<\/p>\n\n\n\n

Tell your rheumatology team about prior positive tests, previous treatment, vaccinations, travel or residence in higher-risk settings, known exposures, and current symptoms. Old records may be more informative than simply ordering the same screening test again.<\/p>\n\n\n\n

The main tests and what they answer<\/h2>\n\n\n\n
Test<\/th>Main question<\/th>What it does not settle alone<\/th><\/tr><\/thead>
QuantiFERON-TB Gold Plus<\/a><\/td>Is there an immune response consistent with TB infection?<\/td>Whether infection is latent or active.<\/td><\/tr>
Hepatitis B surface antigen with reflex confirmation<\/a><\/td>Is there evidence that may indicate current hepatitis B infection?<\/td>The full stage of infection or the treatment plan.<\/td><\/tr>
Hepatitis B surface antibody, quantitative<\/a><\/td>Is surface antibody present, as may occur after vaccination or recovery?<\/td>Whether prior natural infection occurred.<\/td><\/tr>
Hepatitis B core antibody, total<\/a><\/td>Is there evidence of previous or current natural exposure to hepatitis B?<\/td>Whether infection is currently active.<\/td><\/tr>
Hepatitis C antibody with reflex to RNA quantitative PCR<\/a><\/td>Is antibody present, and if reactive, is viral RNA detected?<\/td>A reactive antibody result alone cannot establish current infection.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Understanding a TB blood-test result<\/h2>\n\n\n\n

QuantiFERON-TB Gold Plus<\/a> is an interferon-gamma release assay, or IGRA. It measures an immune response to TB-related antigens. According to CDC guidance on TB blood testing<\/a>, prior BCG vaccination does not cause a positive IGRA result.<\/p>\n\n\n\n

A positive result generally leads to a clinical evaluation to distinguish latent infection from active disease. That may include a symptom review, chest imaging, and additional investigations. The screening blood test cannot make this distinction by itself.<\/p>\n\n\n\n

A negative result is not a guarantee that TB is absent, particularly with recent exposure, symptoms, or impaired immune responses. An indeterminate result is not a negative result; it means the test did not provide a clear answer. The clinician decides whether another specimen or another approach is appropriate.<\/p>\n\n\n\n

If you have documentation of a previous positive TB test or completed treatment, share it before booking another test. Repeating an IGRA is generally not a way to prove that treatment worked. Collection and specimen-handling requirements also matter, so confirm instructions for your appointment.<\/p>\n\n\n\n

Why hepatitis B screening uses three markers<\/h2>\n\n\n\n
\"Three
HBsAg, anti-HBs, and total anti-HBc answer different questions. Interpret their pattern with clinical and vaccination history.<\/figcaption><\/figure>\n\n\n\n

Hepatitis B screening needs more context than the word \u201cpositive.\u201d Surface antigen<\/a>, surface antibody<\/a>, and total core antibody<\/a> answer different questions. The CDC's recommended triple-panel approach<\/a> uses all three.<\/p>\n\n\n\n

The Hepatitis B Titer Test Panel<\/a> offered by Ulta includes those three tests. If you already have recent results, ask whether they are adequate before repeating the panel.<\/p>\n\n\n\n

Illustrative pattern<\/th>Possible interpretation<\/th>Why follow-up matters<\/th><\/tr><\/thead>
Surface antigen<\/a> negative; core antibody<\/a> negative; surface antibody<\/a> positive<\/td>May be consistent with vaccine-related immunity when the vaccination history fits.<\/td>The clinician considers vaccination records and the full clinical context.<\/td><\/tr>
Surface antigen<\/a> negative; core antibody<\/a> positive; surface antibody<\/a> positive<\/td>Commonly indicates resolved natural infection.<\/td>Past infection can still matter for reactivation risk during immunosuppression.<\/td><\/tr>
Surface antigen<\/a> positive<\/td>May indicate current infection.<\/td>Confirmation, further evaluation, and a treatment-safety plan are needed.<\/td><\/tr>
Surface antigen<\/a> negative; core antibody<\/a> positive; surface antibody<\/a> negative<\/td>An isolated core-antibody pattern has several possible explanations.<\/td>It should not be automatically labeled active infection or vaccine immunity.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

All three markers being negative may indicate susceptibility, but interpretation also considers vaccine history, timing, and immune status. These patterns are educational examples, not a complete diagnostic algorithm.<\/p>\n\n\n\n

For a person with evidence of prior hepatitis B, the planned medication influences whether preventive antiviral treatment or a monitoring plan is appropriate. The CDC screening recommendations<\/a> explain why identifying past infection matters before immunosuppressive therapy. A positive antibody does not automatically make RA treatment impossible.<\/p>\n\n\n\n

Why a hepatitis C antibody result may need a second step<\/h2>\n\n\n\n

The hepatitis C antibody test with reflex to RNA quantitative PCR<\/a> begins with an antibody screen. If the screen is reactive, the reflex step checks for viral RNA, subject to the laboratory's testing criteria.<\/p>\n\n\n\n

A reactive antibody can reflect current infection, a past infection that has cleared, or sometimes a false-positive result. RNA detected on the reflex test<\/a> supports current infection and requires clinical follow-up. RNA not detected<\/a> generally means there is no current infection, although recent exposure or other clinical concerns may justify additional testing.<\/p>\n\n\n\n

CDC guidance<\/a> also notes that recent exposure and immunocompromised status can change the testing approach. Tell the clinician about those circumstances even if an initial antibody result is negative.<\/p>\n\n\n\n

Screening is one part of getting ready<\/h2>\n\n\n\n

The treating team may also request a CBC with differential and platelets<\/a> or comprehensive metabolic panel<\/a> for baseline safety assessment. These panels do not replace infection-specific screening. Vaccination planning, current infection symptoms, other medical conditions, and medicine-specific precautions remain part of the visit.<\/p>\n\n\n\n

Do not assume that a single negative screening panel means you are cleared to begin treatment. The prescriber must review the results and any outstanding investigations. Similarly, repeat screening during treatment should follow exposure risks, clinical circumstances, and the medicine's requirements rather than an automatic schedule selected online.<\/p>\n\n\n\n

Questions to ask before the first dose<\/h2>\n\n\n\n