Subsets and Function Changes of Th Cells in the Bone Marrow of Patients with Immune Related Pancytopenia.

Objectives

To explore the subsets and function of T helper (Th) in bone marrow of the patients with immune related pancytopenia(IRP).

Methods

The CD₄⁺ cells producing IFN-γ or IL-4 in cytoplasm were defined as Th1 or Th2 cells respectively. All these cells in bone marrow were measured from 16 normal controls, 25 untreated IRP patients; The mRNA expressions of IL-4, IL-10, IFN-γ and IL-2 genes in unstimulated bone marrow mononuclear cells(BMMNC)from 25 untreated IRP patients, 10 normal controls were measured by reverse transcription polymerase chain reaction (RT-PCR).

Results

The percentage of Th1 cells, Th2 cells and ratio of Th1/Th2 in bone marrow of normal controls was: 0.42%, 0.24%, 1.57 respectively, and the percentage of Th1 cells in untreated patients with IRP was 0.58%, which was not markedly different from the that of normal controls(t=0.903, P>0.05). But the percentage of Th2 cells of the patients with IRP was significantly higher than that of normal controls(t=4.673, P<0.01), and the balance of Th1/Th2 shifted to Th2 more significantly by comparing to that of normal controls (t=4.880, P<0.01). The mRNA expressions of IL-4 and IL-10 in the Th2 cells of the untreated IRP patients were significantly higher than those of the normal controls, however difference of the expressions of IFN-γ and IL-2 in the Th1 cells were not significantly.

Conclusions

The percentage of Th2 cells increased in the patients with IRP, and the balance of Th1/Th2 shifted to Th2. And the expression of Th2 type cytokines was more frequent in IRP. The imbalance of subtypes of Th lymphocytes and hyperfunction of Th2 lymphocytes might play important roles in the pathogenic mechanism of IRP, which lead to more B lymphocytes and producing autoantibodies consistenly.