Incidence of Antiphospholipid Antibodies in Patients With Immune Thrombocytopenia and Correlation With Treatment With Steroids in North Indian Population.

INTRODUCTION

Antiphospholipid antibodies (APLAs) have been variably reported in 14% to 75% of patients with immune thrombocytopenia (ITP). There is lack of Indian data on incidence of APLA in ITP.

OBJECTIVE

We studied the incidence of APLA in patients with pediatric and adult Indian ITP.

MATERIALS AND METHODS

We prospectively studied 100 patients including acute (n = 37), persistent (n = 13), and chronic (n = 50) ITP. Male to female ratio was 1.22:1. Median age was 18 years (1.5-56). All patients underwent investigations for lupus anticoagulant (LA), anticardiolipin (aCL) immunoglobulin G (IgG) and IgM antibodies, and anti-β2 glycoprotein 1 (β2GP1) IgG and IgM antibodies. Patients with secondary ITP were excluded. Bleeding manifestations were recorded. Patients with acute and persistent ITP were assessed for steroid response. Response rates were compared between APLA-positive and APLA-negative patients.

RESULTS

Antiphospholipid antibodies were detected in ∼12% of patients with ITP: 8.1% (3 of 37) in acute, 0% (0 of 13) in persistent, and 18% (9 of 50) in chronic ITP. Anti-β2GP1 antibodies were most frequent (9%). Only 2 patients each were positive for anti-aCL antibodies and LA. Although platelet counts were significantly higher in APLA-positive patients, there was no significant difference in bleeding between the APLA-positive versus APLA-negative patients with ITP. There was also no significant difference in steroid response between APLA-positive and APLA-negative patients with acute/persistent ITP. In the short follow-up (median 8 months), none of the APLA-positive patients developed thrombosis.

CONCLUSIONS

Incidence of APLA in Indian population was lower than reported in the West, which indicates that not all patients of ITP need to be subjected to these manifestations upfront at diagnosis.