Effective Tuesday, March 11, 2014, the University of Iowa Hospitals and Clinics core clinical chemistry laboratory will institute new assays for the antiphospholipid antibody tests for cardiolipin and beta-2 glycoprotein I.  These replace the following tests: BETA-2 GLYCOPROTEIN I ANTIBODIES, IGG AND IGM (LAB1265) and ANTI-CARDIOLIPIN ATBYS G/M (LAB1253).  IgA antibodies for cardiolipin and beta-2 glycoprotein I will also now be available.

Reference ranges are standardized to the 99th percentile cutoff as described by the Miyakis/Sapporo criteria (International Consensus Statement on an Update of the Classification Criteria for Definite Antiphospholipid Syndrome, Journal of Thrombosis and Hemostasis 2006; 4:295-306).  A positive of 20 U/mL or greater for beta-2 glycoprotein and/or cardiolipin IgG or IgM assays can fulfill the laboratory portion of the criteria needed for diagnosis of antiphospholipid syndrome (two positives at least 12 weeks apart are required).

Anti-cardiolipin and anti-beta-2 glycoprotein of the IgA isotype are not part of the formal laboratory criteria for antiphospholipid syndrome due to lack of specificity.  The presence of IgA antibodies to cardiolipin or beta-2-glycoprotein I at levels greater than 99th percentile is, however, part of the SLICC (Systemic Lupus International Collaborating Clinics) Classification Criteria for Systemic Lupus Erythematosus immunologic criteria.

Test availability is 24 hours/day, 7 days a week (including holidays), with turn-around time of 2 hours or less upon receipt in the laboratory.  Other details on the tests are as follows:

Test name	Epic #	Specimen*	Reference range (U/mL)
BETA-2 GLYCOPROTEIN I IGA	LAB8035	Plasma separator tube	Negative: < 20 Positive: 20 or greater
BETA-2 GLYCOPROTEIN I IGG	LAB8036
BETA-2 GLYCOPROTEIN I IGM	LAB8037
CARDIOLIPIN IGA	LAB8038
CARDIOLIPIN IGG	LAB8039
CARDIOLIPIN IGM	LAB8040

* 3 mL whole blood or two pediatric microtainers

These changes do not impact LUPUS ANTICOAGULANT (LAB478) performed by coagulation methods.  This will continue to be offered without any changes.

Questions should be directed to Matthew Krasowski, MD, PhD, medical director of the Clinical Chemistry Laboratory (384-9380, matthew-krasowski@uiowa.edu).