Naslov
Laboratory evaluation of antiphospholipid antibodies: have the recommended guidelines for diagnosing antiphospholipid syndromebeen followed

Autori
Margetić Sandra ; Tešija Kuna Andrea, Vukasović Ines, Vrkić Nada

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, ostalo

Skup
XXIV Congress of the International Society on Thrombosis and Haemostasis

Mjesto i datum
Amsterdam, Nizozemska, 29.06.2013. - 04.07.2013

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
antiphospholipid antibodies; guidelines; antiphospholipid syndrome; lupus anticoagulant; anticardiolipin antibodies; anti-beta2-glycoprotein-1 antibodies

Sažetak
Background: In addition to clinical indicators, laboratory evaluation of antiphospholipid antibodies (aPLAs) is an integral part of the diagnostic criteria for antiphospholipid syndrome (APS). Based primarily on the method detection, there are three major subgroups of aPLAs: lupus anticoagulant (LA), anticardiolipin antibodies (ACL) and anti- beta2-glycoprotein-1 antibodies (anti- beta2GPI). According to the International Society on Thrombosis and Haemostasis (ISTH) recommended guidelines, the laboratory investigation of aPLAs should always include determination of all three groups of antibodies. Aim: The aim of this study was to analyze the results of laboratory evaluation of aPLAs in unselected consecutive patients who referred for testing during one year period. Methods: LA antibodies were identified by a panel of commercial coagulation assays (Siemens, Germany) including screening tests (activated partial thromboplastin time (APTT, Actin FSL), APTT mixing test, dilute Russells viper venom time dRVVT screen and dRVVT confirmation test. The laboratory evaluation of ACL and anti-2GPI antibodies was performed using enzyme-linked immunosorbent (ELISA) assays (Orgentec, Germany) for immunoglobulin M (IgM) and immunoglobulin G (IgG) isotypes. Results: The prevalence of positive results for individual aPLAs were: LA=33/991, 3.3% ; ACL=67/1253, 5.3% (IgG=22/67, 33% ; IgM=31/67, 46% ; IgG and IgM=14/67, 21%) and anti- 2GPI=7/177, 4.0% (IgG 4/7 ; IgM 3/7, IgG and IgM 1/7). Only for 11/86 (13%) of all positive patients, laboratory investigation included all three groups of aPLAs. Anti-2GPI were ordered only for 16/86 (18.6%) patients. LA and ACL were simultaneously ordered for 48/86 (56%) of positive patients, while LA alone was ordered for 10/86 (12%) patients and ACL alone for 33/86 (38%) patients. Among 44 positive cases for simultaneously ordered LA and ACL, 15/44 (34%) were positive for both LA and ACL, 9/44 (20%) were LA positive and ACL negative and 20/44 (46%) were ACL positive and LA negative. Of the total 86 positive results, LA was ordered for 58 patients (67%) with positivity of 57% (33/58), while ACL antibodies were ordered for 77 (90%) patients with positivity of 87% (67/77). Only in 4/33 (12%) of LA positives, 8/67 (11.9%) of ACL positives and 1/7 of anti-2GPI positives, laboratory evaluation was performed on two separate occasions at least 12 weeks apart. Conclusions: The laboratory investigation of individual aPLAs among unselected consecutive patients had shown the prevalence of 3.3-5.3% for individual subgroups of antibodies, with the highest prevalence of ACL antibodies. Our results indicated that laboratory investigation has not been completely performed in accordance with the recommended guidelines on testing, since only for a small number of patients testing was performed for all three subgroups of antibodies or at least for two (LA and ACL). Additionally, for a minority of positive patients testing was ordered on two separate occasions at least after 12 weeks. It is obvious that laboratory has to take the more substantial role in the investigation process of APS, than just providing doctors with numbers. The corrective actions should primarily include ongoing education of clinicians pointing the importance of determining all three subgroups of aPLAs, since patients may be negative for one subgroup of aPLAs and positive for others.

Izvorni jezik
Engleski

Znanstvena područja
Kliničke medicinske znanosti

Napomena
PB 3.62-5 Postersko izlaganje i usmena prezentacija rada

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