Lupus Anticoagulanthypoprothrombinemia Syndrome (LAHPS): Report of 4 Cases

REMOTTI L; INGRATTI M; GROSSO S; BLANCO A; SÁNCHEZ LUCEROS A; ROMERO ML; VERA MP

Berlin

Congreso; 26th Congress of ISTH & 63rd Annual Scientific and Standardization Committee (SSC) Meeting; 2017

International Society on Thrombosis and Haemostasis

Background: LAHPS, the association of acquired FII deficiency and lupus anticoagulant (LA), is a rare disorder caused by aFII antibodies. It is drastically different from antiphospholipid syndrome (APS); it may cause predisposition to severe bleeding, in addition or not to thrombosis.Aims: We report and discuss 4 cases of LAHPS.Methods: LA was detected using a sensitive APTT and DRVVT, according to the ISTH guidelines. Hypoprothrombinemia was defined as FII under reference value (< 70IU/dL); abnormal PT and FII, were corrected by normal plasma (NP). Coagulation factors were determined by one-stage methods; those tests based on APTT were interfered by LA.Results: Table 1 summarises laboratory results and clinical features. All cases showed abnormal PT, corrected by NP, and prolonged APTT, not corrected by NP. Cofactor effect on APTT was observed when FII was ≤25IU/dL. No time-temperature dependent inhibition was detected. Cases showed APTT and DRVVT tests compatible with LA, as well as low FII (8-52IU/dL) corrected by NP. In 3/4 cases, lowFVIII (1.2-50IU/dL) and FIX (2-40IU/dL) and increased apparent activity on progressive dilutions of sample were observed. Acetic acid clot solubility test was abnormal, suggesting low FXIII in 1 patient; he also showed thrombocytopenia. Other tests, like those to study von Willebrand disease and platelet function, were normal. One case was asymptomatic, the rest had suffered from bleeding. No other associated condition was found.Conclusions: LAHPS has a heterogeneous spectrum of appearance. While it has been reported associated with other clinical conditions (primary APS, infections, drugs, systemic lupus erythematosus), in any of cases presented here, an associated condition was found; all except one, referred bleeding symptoms. LAHPS diagnosis is challenging; it should be suspected when abnormal PT+positive LA results were observed, mainly in the context of bleeding complications.A careful analysis should be done in order to achieve accurate diagnosis.