Assessment of the underlying causes of the immune thrombocytopenia: Ten years experience.

OBJECTIVE: Immune thrombocytopenia (ITP) is an immune haematologic disorder causing platelet destruction mediated by anti-platelet antibodies. In this study we aimed to evaluate the clinical and laboratory variables of ITP patients in southeast of Turkey. METHODS: In this retrospective study 167 ITP patients between 2005 and 2015 were evaluated. All patients were screened for immunological parameters including ANA (antinuclear antibodies), anti dsDNA (anti-double-stranded-DNA), ACA(anti-cardiolipin) IgM and IgG, LA (lupus anticoagulants). All patients were screened for Helicobacter pylori, HBsAg (Hepatitis B surface antigen), anti-HCV (hepatitis C virus antibody), and anti-HIV ½ (HIV antibody) and brucellosis.. RESULTS: Among the patients, 50 (29.9%) patients were male, 117 (70.1%) were female. The age range of patients was 18-86 (mean 38.16±14). In 56 patients (33.5%) splenectomy was performed. 36 patients (21.6%) were positive for ANA, 5 (3%) were positive for anti dsDNA, 14 (8.4%) for ACA Ig G, and 14 (8.4%) patients for ACA IgM. LA was tested in 165 patients and 30 (18%) patients were positive for LA. Microbiologic evaluation was as follows: 16 patients (9.6%) were positive for HbsAg, 109 (65.3%) positive for Anti-HBs, 5 positive for anti-HCV (3%), 56 (33.5%) patients were positive for Helicobacter pylori antigen, 5 (2.9%) for Brucella and one patient was positive for anti-HIV ½. CONCLUSIONS: Immune thrombocytopenia patients have to be evaluated according to their demographic characteristics and laboratory results. Secondary causes of ITP were HIV, HCV, Helicobacter pylori, brucellosis, tuberculosis, and autoimmune diseases in our region. Management of ITP patients can change in different regions.

Risky business: the interpretation, use, and abuse of antiphospholipid antibody tests in clinical practice.

Antiphospholipid antibodies (aPL) are best considered as risk factors. aPL are not diagnostic tests and considering them as such can be misleading and may direct attention away from the more important clinical issue of risk modification and management. When considering aPL as risk factors, quantitative aPL tests such enzyme-linked immunosorbent assay (ELISA) for anticardiolipin (aCL) and anti-beta(2)-glycoprotein I (anti-beta(2)GPI) antibodies, should be interpreted carefully. Risk for clinical manifestations appears to be associated with moderate to high levels of these autoantibodies. Lower levels may be statistically abnormal compared with a control population, but may not be associated with the risk of thrombosis or pregnancy loss. Lupus anticoagulants (LA) are generally thought to be more strongly associated with the risk of clinical manifestation of antiphospholipid syndrome (APS) than aCL and anti-beta(2)GPI antibodies. One reason for the stronger association may be related to patients' antibody titers. LA assays are not very analytically sensitive, i.e. a relatively high concentration of antibodies is required to prolong the clotting time in these tests. Thus, the presence of LA indicates a high titer of aPL and this, rather than the intrinsic functional characteristics of LA antibodies, may explain the high risk of clinical manifestations associated with LA.

Thrombotic risk assessment in the antiphospholipid syndrome requires more than the quantification of lupus anticoagulants.

Lupus anticoagulants (LACs) are associated with thromboembolic complications (TECs). LACs can be detected by their anticoagulant properties in thrombin generation assays, by the peak height (PH) and lag time (LT). To assess the thrombotic risk in LAC-positive patients, we have expressed the LAC activity quantitatively by PH/LT calibration curves, constructed for mixtures of monoclonal antibodies against beta2-glycoprotein I (beta2GPI) and prothrombin, spiked in normal plasma. PH/LT was determined in LAC patients, with (n = 38) and without (n = 21) TECs and converted into arbitrary LAC units. LAC titers ranged from 0 to 200 AU/mL, with 5 of 59 patients being negative. In the positive LAC titer population (54 of 59), LAC and anti-beta2GPI immunoglobulin G (IgG) titers correlated with TECs, with odds ratios of 3.54 (95% CI, 1.0-1.7) and 10.0 (95% CI, 1.98-50.6), respectively. In patients with single or combined low titers, useful predictions on thrombosis could be made only after additional measurements of soluble P-selectin and factor VII. This layered strategy yielded positive and negative predictive values, sensitivity, and specificity values approximately 90% in this subgroup. Hence, LAC and anti-beta2GPI IgG titers, when combined with selected markers of the hypercoagulable state, allow a relevant thrombotic risk assessment in nearly all patients with LACs.

Learning from peer assessment: the role of the external quality assurance multilaboratory thrombophilia test process.

The quality control process is a critical feature of pathology best practice. In addition to internal quality control processes applied on a test-to-test or day-to-day basis, the participation of laboratories in external quality assurance programs (QAPs) is critical to achieving ongoing test accuracy. There are several such programs operating in the international arena. With respect to thrombophilia, these include the Australia-based Royal College of Pathologists of Australia QAP, the United Kingdom-based National External Quality Assessment Service, and the International Thrombophilia External Quality Assessment Scheme, based in the Netherlands. Although there are some similarities between the programs, some diversity is also apparent. Each of the programs assess for the common markers of congenital thrombophilia, such as antithrombin, protein C, protein S, and activated protein C resistance. Testing of some acquired markers of thrombophilia, such as lupus anticoagulant, and genetic tests such as factor V Leiden and prothrombin G20210A mutation, are also available. This report focuses on some recent trends from these programs.