OBJECTIVETo investigate the changes of relative telomere length (RTL) of peripheral blood (PB) CD3⁺, CD3⁺CD4⁺, CD3⁺CD8⁺T lymphocytes, CD19⁺B lymphocytes and bone marrow (BM) CD34⁺ cells and its association with disease severity in untreated patients with immuno-related pancytopenia (IRP).

METHODSThe PB CD3⁺ , CD3⁺ CD4⁺ , CD3⁺ CD8⁺ T lymphocytes, CD19⁺ B lymphocytes, and BM CD34⁺ cells were purified by magnetic activated cell sorting (MACS), and RTL were measured with flow-fluorescence in situ hybridization (FLOW-FISH).

RESULTSThe RTL of CD3⁺, CD3⁺CD4⁺ , and CD3⁺CD8⁺T lymphocytes in untreated IRP patients were (27.754 ± 16.323)%, (7.526 ± 3.745)% and (25.854 ± 14.789)%, respectivly, which were significantly shorter than those in healthy-controls (54.555 ± 19.782)%, (12.096 ± 2.805)%, and (38.367 ± 4.626)% (P<0.05). The RTL of CD19⁺ lymphocytes in untreated IRP patients was (22.136 ± 16.142)%, which was significantly shorter than that in healthy controls (42.846 ± 16.353)% (P<0.01). There was no significant difference of BM CD34⁺ cells RTL between the untreated IRP patients (22.528 ± 21.601)% and the healthy controls (23.936 ± 19.822)% (P>0.05). There were significantly positive correlations between the RTL of B lymphocytes and the count of white blood cell (r=0.706, P=0.015). There were negative correlations between RTL of B lymphocytes and the clinical symptoms (r=-0.613, P=0.045) and positive correlations with therapeutic effect (r=0.775, P=0.005).

CONCLUSIONThe shorter RTL of CD3⁺, CD3⁺CD4⁺, CD3⁺CD8⁺, CD19⁺ lymphocytes, and the normal RTL of BM CD34⁺ cells in untreated IRP patients were identified, which might imply that IRP is a type of acquired autoimmune diseases.