Fehldiagnose HIT bei einem thrombozytopenen Patienten – Fallbeschreibung mit Anmerkungen zur Differenzialdiagnose*

Zusammenfassung

Wir berichten über einen Patienten mit klinischen Zeichen einer medikamenteninduzierten Thrombozytopenie, bei welchem die Diagnose initial durch einen positiven HIT-Antikörpertest fehlgeleitet wurde. Der präsentierte Fall unterstreicht, dass ein positiver Antigentest bei HIT-Verdacht weiter untersucht werden muss, besonders bei niedriger Prä-Test-Wahrscheinlichkeit. Dies ist besonders wichtig, wenn der Antigentest nicht IgG-spezifisch ist. Wir empfehlen die Anwendung des klinischen „4 T-scores“ sowie eine weitere Laboraufbereitung von positiven HIT-Antigentesten mithilfe funktioneller Tests, die einzigen, welche die thrombozytenaktivierende Eigenschaft von HIT-Antikörpern nachweisen können (nicht aktivierende, niedrigtitrige IgG-Antikörper haben wahrscheinlich keine klinische Relevanz).

Abstract

We report on a patient with clinical signs of drug-induced thrombocytopenia in whom the correct diagnosis was delayed by a positive HIT-antibody test. The clinical course demonstrates that a positive antigen test in suspected HIT has to be further examined, especially if pre-test probability is low. This is particularly important if the assay is not IgG-specific. We recommend the use of the “4-T”-score as well as follow-up of positive HIT-antigen tests with functional assays which are the only tests that can demonstrate the platelet activating property of HIT-antibodies (nonactivating, low-titer IgG antibodies are probably clinically irrelevant).

Schlüsselwörter

heparininduzierte Thrombozytopenie - HIT - piperacillininduzierte Thrombozytopenie

Key words

Heparin-induced thrombocytopenia - HIT - piperacillin-induced thrombocytopenia

• Literatur

• 1 Greinacher A, Selleng K. Thrombocytopenia in the intensive care unit patient. Hematology Am Soc Hematol Educ Program 2010; 2010: 135-143
• 2 Greinacher A, Eichler P, Lubenow N et al. Drug-induced and drug-dependent immune thrombocytopenias. Rev Clin Exp Hematol 2001; 5: 166-200
• 3 Greinacher A, Juhl D, Strobel U et al. Heparin-induced thrombocytopenia: a prospective study on the incidence, platelet-activating capacity and clinical significance of antiplatelet factor 4/heparin antibodies of the IgG, IgM, and IgA classes. J Thromb Haemost 2007; 5: 1666-1673
• 4 Lo GK, Sigouin CS, Warkentin TE. What is the potential for overdiagnosis of heparin-induced thrombocytopenia?. Am J Hematol 2007; 82: 1037-1043
• 5 Hron G, Knutson F, Thiele T et al. Alternative diagnosis to heparin-induced thrombocytopenia in two critically ill patients despite a positive PF4/heparin-antibody test. Ups J Med Sci 2013; 118: 279-284
• 6 Eichler P, Budde U, Haas S et al. First workshop for detection of heparin-induced antibodies: validation of the heparin-induced platelet-activation test (HIPA) in comparison with a PF4/heparin ELISA. Thromb Haemost 1999; 81: 625-629
• 7 Warkentin TE, Greinacher A, Koster A et al. American College of Chest Physicians. Treatment and prevention of heparin-induced thrombocytopenia: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Chest 2008; 133 (Suppl. 06) S340-S380
• 8 Martel N, Lee J, Wells PS. Risk for heparin-induced thrombocytopenia with unfractionated and low-molecular-weight heparin thromboprophylaxis: a meta-analysis. Blood 2005; 106: 2710-2715
• 9 Rousan TA, Aldoss IT, Cowley jr. BD et al. Recurrent acute thrombocytopenia in the hospitalized patient: sepsis, DIC, HIT, or antibiotic-induced thrombocytopenia. Am J Hematol 2010; 85: 71-74
• 10 Lo GK, Juhl D, Warkentin TE et al. Evaluation of pretest clinical score (4 Tʼs) for the diagnosis of heparin-induced thrombocytopenia in two clinical settings. J Thromb Haemost 2006; 4: 759-765
• 11 Bakchoul T, Giptner A, Najaoui A et al. Prospective evaluation of PF4/heparin immunoassays for the diagnosis of heparin-induced thrombocytopenia. J Thromb Haemost 2009; 7: 1260-1265
• 12 Lindhoff-Last E, Gerdsen F, Ackermann H et al. Determination of heparin-platelet factor 4-IgG antibodies improves diagnosis of heparin-induced thrombocytopenia. Br J Haematol 2001; 113: 886-890