Duke University Health System, Box 3486, Room 304 Sands Bldg, Durham, NC 27710, USA.
Am J Clin Pathol. 2010 Nov;134(5):774-80. doi: 10.1309/AJCPG0MNR5NGKNFX.
Platelet factor 4 (PF4)/heparin antibody, typically associated with heparin therapy, is reported in some heparin-naive people. Seroprevalence in the general population, however, remains unclear. We prospectively evaluated PF4/heparin antibody in approximately 4,000 blood bank donors using a commercial enzyme-linked immunosorbent assay for initial and then repeated (confirmatory) testing. Antibody was detected initially in 249 (6.6%; 95% confidence interval [CI], 5.8%-7.4%) of 3,795 donors and repeatedly in 163 (4.3%; 95% CI, 3.7%-5.0%) of 3,789 evaluable donors. "Unconfirmed" positives were mostly (93%) low positives (optical density [OD] = 0.40-0.59). Of 163 repeatedly positive samples, 116 (71.2%) were low positives, and 124 (76.1%) exhibited heparin-dependent binding. Predominant isotypes of intermediate to high seropositive samples (OD >0.6) were IgG (20/39 [51%]), IgM (9/39 [23%]), and indeterminate (10/39 [26%]). The marked background seroprevalence of PF4/heparin antibody (4.3%-6.6%) with the preponderance of low (and frequently nonreproducible) positives in blood donors suggests the need for further assay calibration, categorization of antibody level, and studies evaluating clinical relevance of "naturally occurring" PF4/heparin antibodies.
血小板因子 4 (PF4)/肝素抗体通常与肝素治疗有关，但也有一些肝素初治人群会出现这种抗体。然而，一般人群的血清流行率仍不清楚。我们使用商业酶联免疫吸附试验对大约 4000 名血库献血者进行前瞻性评估，最初进行检测，然后进行重复（确认）检测。在 3795 名供者中，最初有 249 名（6.6%；95%置信区间[CI]，5.8%-7.4%）检测到抗体，在 3789 名可评估供者中，重复检测有 163 名（4.3%；95%CI，3.7%-5.0%）检测到抗体。“未确认”阳性者大多（93%）为低阳性（吸光度[OD] = 0.40-0.59）。在 163 例重复阳性样本中，116 例（71.2%）为低阳性，124 例（76.1%）表现出肝素依赖性结合。中至高阳性（OD>0.6）的主要免疫球蛋白型为 IgG（20/39 [51%]）、IgM（9/39 [23%]）和不确定（10/39 [26%]）。血小板因子 4/肝素抗体的显著背景血清流行率（4.3%-6.6%），加上献血者中低（且常不可重复）阳性的优势，表明需要进一步校准检测、抗体水平分类以及评估“天然存在”血小板因子 4/肝素抗体的临床相关性的研究。
