Page 126 - 2021_03-Haematologica-web

X. Li et al.
Table 1. Clinical characteristics of untreated immune thrombocytopenia patients.
Patient No. Sex/Age (yr) Platelets counts Bleeding symptoms Autoantibodies
(x109/L) Anti-GPIb/IX Anti-GPIIb/IIIa
1 M/76 2 EP + +
2 M/62 2 EP,GUH + +
3 M/62 10 PT,EC + +
4 F/56 8 EC,EP,GH + +
5 M/23 14 EC,GH + -
6 F/26 21 EC + -
7 F/50 4 None + -
8 M/18 4 EP,GUH + -
9 M/44 4 EC - +
10 F/33 1 EC,GH - +
11 F/43 6 GH,GUH - +
12 M/37 20 EC,GH,EP - +
13 M/50 1 GH,EC - -
14 M/21 6 EC,GUH - -
15 F/55 9 GH,EC - -
16 M/16 10 EC - -
17 F/30 11 EC,GH - -
18 M/73 1 PT,EC + +
19 F/33 16 GH,EC,GUH + +
20 F/76 2 EC,GH + -
21 M/23 29 EC + -
22 F/54 1 EC,PT - +
23 M/26 21 EC - +
24 F/66 5 EC,GH - +
25 F/24 7 EC,PT - +
26 M/47 19 EC - -
27 F/48 3 EC - -
28 M/16 6 EC - -
29 F/27 3 GH,EC - -
30 M/36 3 None - -
31 F/34 15 EC - -
32 F/47 7 EC,PT - -
33 M/32 2 EC,GH - -
34 M/27 20 None - -
35 M/28 5 EC,PT - -
36 F/39 10 None - -
No: number; F: female; M: male; yr: years; PT: petechiae; EC: ecchymoses; EP: epistaxis; GH: gingival hemorrhage; GUH: genitourinary hemorrhage. Plasma samples from patient No.1-50 were collected for the detection of secreted human leukocyte antigen-G (sHLA-G) with enzyme linked immunosorbent assay (ELISA). Peripheral blood mononuclear cell (PBMC) from patient No.1-17 were isolated for the in vitro investigation of membrane-bound HLA-G (mHLA-G) and immunoglobulin-like transcript (ILT) in immune cells.
Statistical analysis
Data are presented as mean ± standard deviation (SD). Differences between rhHLA-G modulated and unmodulated cells were determined by paired Student t tests. Correlative analysis was determined by nonparametric Pearson correlation. All the other statistics were analyzed with the Mann-Whitney U test. P<0.05 was considered a significant difference.
Results
HLA-G and ILT expression reduced in ITP patients
Platelet antibodies were identified by monoclonal anti-
body immobilization of platelet antigens (MAIPA) assay (shown in Table 1). In order to investigate the level of sHLA-G in ITP patients, platelet poor plasma (PPP) was isolated and sHLA-G was measured by enzyme linked immunosorbent assay (ELISA). Plasma HLA-G was reduced in ITP patients with anti-platelet antibodies com- pared to patients without autoantibodies and healthy controls. Among these patients, 11 were positive for anti- GPIIb/IIIa antibodies, 12 for anti-GPIb/IX antibodies, and 11 for both. However, no significant differences were found in the sHLA-G levels based on antibody type. ITP patients without anti-platelet antibodies showed no sig- nificant difference compared to healthy controls (Figure
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