LETTER
Year : 2015  |  Volume : 61  |  Issue : 4  |  Page : 268

Authors' reply

Correspondence Address:
T Koufakis
Department of Internal Medicine, General Hospital of Larissa, Larissa
Greece

Source of Support: None, Conflict of Interest: None

Check

PMID: 26482023

1. Although heparin-induced thrombocytopenia (HIT) type II is often suspected, its diagnosis remains a challenge. HIT type II diagnosis is established when clinical probability meets compatible results of laboratory testing. Our patient met both criteria, i.e., total 4T score for HIT was 8/8 while enzyme-linked immunosorbent assay (ELISA) test and serotonin release assay (SRA) for platelet factor 4 (PF4)-heparin antibodies proved to be positive. Detection of HIT type II antibodies is not a definite proof of HIT type II. However, the combined use of a functional assay and an immunological assay, as happened in the reported case, enhances the probability of correctly diagnosing HIT type II. ^[2] Therefore, the HIT type II diagnosis in the described case was established according to the current literature evidence. With regard to the cause of pain, the specific patient was diagnosed with thrombosis of the right common iliac and right common femoral veins, which are well-described causes of abdominal pain. ^[3]
2. Indeed, fondaparinux is not U.S. Food and Drug Administration (FDA) approved for the treatment of HIT type II. None of the FDA-approved drugs for the management of HIT type II was available in our hospital at that time. Still, there is enough evidence supporting the fact that fondaparinux can be an alternative, effective, and safe agent for the treatment of HIT. ^{[4],[5],[6],[7],[8]}
3. When the patient was passed on acenocoumarol, bridging therapy with fondaparinux was used. We considered it unnecessary to mention, given that overlap therapy is a well-established, common practice for most physicians.

:: References

1.	Koul AN. A case of probable bemiparin-induced heparin-induced thrombocytopenia type II managed with low-dose fondaparinux. J Postgrad Med 2015;61:267.
2.	Leo A, Winteroll S. Laboratory diagnosis of heparin-induced thrombocytopenia and monitoring of alternative anticoagulants. Clin Diagn Lab Immunol 2003;10:731-40.
3.	Koopman MM, Sluzewski M, van der Heul C. Deep-vein thrombosis--an unusual cause of low abdominal pain. Neth J Med 1991;39:346-9.
4.	Warkentin TE. How I diagnose and manage HIT. Hematology Am Soc Hematol Educ Program 2011;2011:143-9.
5.	Kuo KH, Kovacs MJ. Successful treatment of heparin induced thrombocytopenia (HIT) with fondaparinux. Thromb Haemost 2005;93:999-1000.
6.	Lobo B, Finch C, Howard A, Minhas S. Fondaparinux for the treatment of patients with acute heparin-induced thrombocytopenia. Thromb Haemost 2008;99:208-14.
7.	Grouzi E, Kyriakou E, Panagou I, Spiliotopoulou I. Fondaparinux for the treatment of acute heparin-induced thrombocytopenia: A single-center experience. Clin Appl Thromb Hemost 2010;16: 663-7.
8.	Warkentin TE, Pai M, Sheppard JI, Schulman S, Spyropoulos AC, Eikelboom JW. Fondaparinux treatment of acute heparin-induced thrombocytopenia confirmed by the serotonin-release assay: A 30-month, 16-patient case series. J Thromb Haemost 2011;9:2389-96.