Evaluating T-Cell Large Granular Lymphocytes in ITP Population

The relationship between T-cell large granular lymphocytes (T-LGL) and immune thrombocytopenia (ITP) is unclear, according to Caroline Gabe and colleagues. In a prospective study, they evaluated T-LGL cells and potential associations with disease outcomes in patients with ITP.

Overall, the authors acknowledged that the presence of T-LGL in ITP is still generally uncertain; however, they reported that abnormal T-LGL counts in some patients could indicate a more severe and treatment-resistant type of ITP. Their findings were presented in Platelets.

Abnormal T-LGL May Indicate More Severe ITP Type

The investigators used flow cytometry to evaluate T-LGL and positive T-cell receptor clonality in patients with ITP or nonimmune thrombocytopenia, with a threshold of ≥0.3 × 10⁹/L for excessive T-LGL. Researchers used descriptive statistics to establish any correlations between T-LGL and ITP, ITP treatment response (rituximab and splenectomy), or T-LGL treatment response.

Gabe reported that 13 (14.3%) of 91 patients with ITP had evidence of excess T-LGL population, whereas 3 (10.3%) out of 29 patients with nonimmune thrombocytopenia had similar evidence. Furthermore, patients with ITP with T-LGL had lower nadir platelet counts (2 × 10⁹/L) compared with those without (47 × 10⁹/L) and had received a median of 6 ITP treatments compared with 3 in patients with ITP without T-LGL.

Rituximab responses occurred in 1 (14.3%) of 7 patients with ITP with T-LGL compared with responses in 6 (54.5%) of 11 without T-LGL. Likewise, responses to splenectomy were successful in 2 (25%) of 8 patients with T-LGL and 9 (56.2%) of 16 without. The authors noted that 4 patients with ITP were administered methotrexate for T-LGL, though none of the patients showed any improvements in platelet count levels.

“Further clinical and biochemical studies are needed to understand the effect of abnormal lymphocytes on the development of thrombocytopenia and on ITP outcomes,” the authors suggested. “Our results do not justify routine testing for T-LGL for all patients with ITP,” they added.

Related: Does Splenectomy Prevent Increased Valve Disease Risk in ITP?