Increased FVIII and Anti-Phospholipid Antibodies Do Not Modify the Clinical Course of Chronic Immune Thrombocytopenia
Authors: Kumar Meet , Bhattyacharyya Maitryee , Datta Shyamali 
Published: October 2019

INTRODUCTION:

Immune thrombocytopenia is a heterogenous disease with majority patients having a mild bleeding phenotype and one-fourth being asymptomatic. Bleeding episodes are usually seen in patients with platelet counts typically <30,000/cumm. There is no study till date to identify patients with platelet count <30,000/cumm and at high risk for bleeding. Although patients who harbor anti phospholipid antibodies have a higher risk of arterial and venous thrombosis, it is not known whether presence of acquired thrombophilia modifies the clinical course of bleeding in low platelet count ITP patients. We evaluated the role of FVIII and lupus anticoagulant in modifying the clinical course of such patients.

MATERIALS AND METHODS:

Patients of all age groups with persistent and chronic immune thrombocytopenia were eligible for study enrolment. Patients with acute ITP and secondary ITP were excluded. Eligible patients were evaluated with baseline parameters, ITP bleeding score (ITP-BAT, version 1.0 by IWG on ITP) at baseline and then at every visit and FVIII and lupus anticoagulant at baseline and repeat at six months.Patients were called for monthly scheduled visits if platelet counts were >30,000/cummand more frequently at lower platelet counts. Patients with any evidence of underlying infection or raised c-reactive protein and procalcitonin were deferred evaluation.All patients were treated as per institutional protocol to avoid treatment bias. Patients were followed up for one year. We finally calculated the average bleeding scores of all patients at different platelet counts (for eg. average of skin, mucosal and organ bleeding scores of all patients that had platelet counts <10,000/cumm, 10-30,000/cumm etc) and analysed it with FVIII and anti-phospholipid antibody levels.

RESULTS:

A total of 45 patients were enrolled with M:F=1:3.2. Median age of patients is 28years (3-72 years). Two patients were excluded (both progressed to SLE) and another two were lost to follow-up. Median duration from ITP diagnosis to study enrolment was 62.4months (8-590 months). Median follow-up of all patients was 14.2 months (13.2-16.4 months). Nine patients had persistent and 32 patients had chronic ITP. ITP-BAT could differentiate intensity of bleeding at different platelet counts by means of bleeding scores (Table 1). Correlation of bleeding scores with prothrombotic markers could not establish a disease course modifying relationship between the two (Table 2).

CONCLUSION:

Presence of high FVIII and anti phosphoilipid antibodies donot modify the bleeding risks in patients with ITP and low platelet counts. Table 1Platelet count (x109/cumm)Total episodesAverage bleeding scoreP value<1014S2.4 M1.4 O0 0.00210-3015S1.4 M0.9 O030-6018S0.3 M0.1 O0>600S0 M0 O0

Table 2 Platelet count <10,000/cumm Platelet count 10-30,000/cumm N Av BS P= N Av BS P= FVIII>150 5 S2.5M1.1O0 0.02 6 S1.1M0.8O0 0.1 FVIII<150 9 S2M0.7O0 11 S1.4M0.6O0 LA1:LA2>2 1 S2.2M1.5O0 0.03 S1.1M0.8O0 0.2 LA1:LA2<1 12 S2.6M1.2O0 S1.2M0.6O0

Table 3 Platelet count 30-60,000/cumm Av BS P= FVIII>150 4 S0.9M0.1O0 0.2 FVIII<150 11 S0.3M0.1O0 LA1:LA2>2 Nil LA1:LA2<1 9 S1.1M0.4O0

Disclosures

No relevant conflicts of interest to declare.