Our CB-CAPs biomarkers detect c4d deposited onto circulating cells as a result of over-activation of the complement system. Measuring CB-CAPs in B-lymphocytes (BC4d), erythrocytes (EC4d) and platelets (PC4d) offers greater insight into the disease process in SLE. Extensive research has revealed the following important associations:

• BC4d aids in the diagnosis of SLE as a stable biomarker of complement activation, offering superior clinical performance characteristics compared to abnormal levels of C3, C4, anti-Smith or anti dsDNA alone.^{1, 2}
• EC4d aids in the diagnosis of SLE and assessing levels of disease activity. Levels of this biomarker have been shown to decrease significantly in conjunction with initiation of effective therapy that leads to a decline in disease activity.^{1, 5, 6}
• PC4d is a biomarker that is closely associated with a history of thrombosis in lupus. Patients with persistent elevated PC4d have been shown to have significant association with thrombosis and ischemic stroke.^{7, 8}

Our expansive menu of immunology testing also includes specialized biomarkers such as:

• Anti-C1q to help assess lupus nephritis^{9, 10}
• Anti-phosphatidylserine/prothrombin (PST/PT), which demonstrates high correlation to lupus anti-coagulant (LAC) without effects from anticoagulant therapy¹¹
• Anti-CarP is a marker of more severe disease prognosis in RA, independent of Anti-CCP or RF status. It is useful in assessing the risk for joint erosions in any RA patient, especially those with seronegative RA.¹²
• Methotrexate polyglutamate (MTXPG) and hydroxychloroquine (HCQ) to assess patient exposure to active blood levels^{12, 13}