Isgrò Antonella, Sirianni Maria Caterina, Gramiccioni Claudia, Mezzaroma Ivano, Fantauzzi Alessandra, Aiuti Fernando
Division of Allergy and Clinical Immunology, University of Rome La Sapienza, Rome, Italy.
Int Arch Allergy Immunol. 2005 Apr;136(4):379-84. doi: 10.1159/000084258. Epub 2005 Mar 2.
Idiopathic CD4+ lymphocytopenia is defined by a stable decrease of CD4+ T cells in the absence of any known cause of immune deficiency. The mechanisms responsible for the immunological impairment are still unknown, but a regenerative failure of hematopoietic stem/progenitor cells has been hypothesized.
We evaluated in the bone marrow (BM) of 5 patients with idiopathic CD4+ lymphocytopenia the phenotype of BM progenitor cells, their differentiation capacity with colony-forming cells and long-term culture-initiating cell assays, in parallel with the spontaneous IL-7 production in the patient sera.
Compared with controls, a regenerative failure of hematopoietic stem cells has been observed, both in 'committed' and in 'uncommitted' progenitor cells, despite high IL-7 serum levels. The percentage of phenotypically primitive CD34+CD38-DR+ cells (this includes the lymphoid precursor cells) was decreased, suggesting an involvement of the more primitive BM compartment in the de novo T cell generation.
Despite the low number of patients, due to the low incidence of the disease, the decrease of primitive precursors sustains the possibility that diminished stem cell precursors might contribute to the development of CD4+ T cell depletion.
特发性CD4+淋巴细胞减少症的定义是在没有任何已知免疫缺陷病因的情况下，CD4+T细胞持续减少。导致免疫功能受损的机制尚不清楚，但有人推测是造血干/祖细胞的再生失败所致。
我们评估了5例特发性CD4+淋巴细胞减少症患者骨髓中祖细胞的表型，通过集落形成细胞和长期培养起始细胞试验检测其分化能力，并同时检测患者血清中白细胞介素-7（IL-7）的自发产生情况。
与对照组相比，尽管血清IL-7水平较高，但在“定向”和“未定向”祖细胞中均观察到造血干细胞的再生失败。表型原始的CD34+CD38-DR+细胞（包括淋巴样前体细胞）百分比降低，提示更原始的骨髓区室参与了新生T细胞的生成。
尽管患者数量较少，由于该疾病发病率较低，但原始前体细胞的减少支持了干细胞前体减少可能导致CD4+T细胞耗竭的可能性。
