Is Interleukin-2 Implicated in the Pathogenesis of Aplastic Anaemia?

Objective: To explore whether or not interleukin-2 (IL-2) is the culprit in the pathogenesis of idiopathic aplastic anaemia. Material and Methods: This retrospective study was carried out at the department of Pathological Sciences and department of Haematology, Manchester Royal Infirmary hospital Christie Hospital, UK. By applying non-radioactive in situ hybridization (ISH) technique, 75 trephine biopsies (10 pre-treated, 35 post-treated idiopathic aplastic anaemia (AA) groups and 30 control group were examined for the presence of total messenger RNA (mRNA) message. Thereafter by using cDNA probe to IL-2, non-radioactive in situ hybridization technique was applied on the 45 trephine biopsies, which contained the total mRNA message. Results: We found that IL-2 positive lymphocytes were decreased in the pre-treated AA group as compared control and post-treated AA groups. These groups were not statistically different from each other. But when IL-2 positive lymphocytes expressed as proportion of CD3 positive lymphocytes among the control, pre-treated and post-treated AA groups, it showed that the proportion of IL-2 positive lymphocytes were decreased in the pre-treated AA group and on statistical analysis, a significant difference was found (P 0.002) from the control group. No significant statistical difference was found between pre-treated and posttreated AA groups versus control group. Conclusion: Our study indicates that the accumulation of lymphocytes is not IL-2 stimulated. Hence IL-2 is not involved in the pathogenesis of idiopathic aplastic anaemia in our study groups