From Pam Owens at TriCore Reference Laboratories in Albuquerque: We are wondering if other labs research their patients’ positive antiphospholipid antibodies (APA) such as the lupus-like inhibitor (LLI, lupus anticoagulant, LA), anti-cardiolipin antibody (ACL) and β-2-glycoprotein 1 (β2GP1)) results to differentiate between persistent and new diagnoses. If so, how far back do they look for a positive? For example, if a patient had a positive result in 2000, 2002, and 2004 but was negative in 2005 and 2010 and is now positive, is she persistent or new, given the eight- year gap? Does the overall diagnosis become a factor, such as if the patient has lupus or rheumatoid arthritis (RA)? We were thinking 5 years was a good look back, but what are others doing?
Hi, Pam, thanks for a head-scratcher! I’ve checked references and farmed your question to a couple of APA experts and am awaiting answers. Meanwhile, I will reference a Dave McGlasson publication on February 23 under the heading “PTT Mix Prolonged Beyond Patient PTT” that describes a patient who had experienced repeated spontaneous abortions and who had elevated ACL results during pregnancy that went back to normal when she was not pregnant. She eventually had two successful pregnancies while treated with aspirin and heparin. Based on this case, we can at least propose that for some patients, the APA waxes and wanes. Don’t give up, I’m going to keep digging for an answer.