目的:研究MYH9相关综合征(MYH9-RD)患者血小板、中性粒细胞的超微结构及其病理特点。方法:采用光学显微镜和透射电镜观察患者外周血的中性粒细胞、血小板及其细胞器形态结构特点。结果:患者具有“巨大血小板、血小板数量减少和中性粒细胞包涵体”三联征;各血小板所含的细胞器数量差异明显,多数血小板的微管系统、n颗粒和致密颗粒数量与血小板体积成比例增加。在所统计的血小板中,有约85%的线粒体肿胀明显,62%的开放管道数量增多,90%血小板有伪足伸出。巨大血小板中有被微管和内质网包围的特殊区域,形态与中性粒细胞包涵体类似。结论:非肌肉肌球蛋白重链-ⅡA(NMMHC-ⅡA)异常导致血小板细胞器分布不均、开放管道数量增加,可能是MYH9-RD患者血小板一直处于被激活状态的重要因素。
Objective: To study the ultrastructure and pathologic features of platelet and neutrophil in pa tients from a family (GXMS family) with non-muscle myosin heavy chain 9 related disease (MYH9-RD). Methods: Morphological characteristics of neutrophils, platelets and their organdies in peripheral blood of patients were observed by optical microscope and transmission electron microscope. Results: The proband in the GXMS family presented with giant platelet, thrombocytopenias and neutrophil inclusions. The platelets of all patients were heterogeneous in organelles content, and had increasing number of dense and agranules, as well as open-canalicular systems, which were proportional to the increased platelet volume. The mitochondrial swelled significantly in 85% of the platelets, the open-tubular increased obviously in 62 % of the platelets, and the pseudopodia were observed in 90% of the platelets. Some regions in giant platelets were surrounded by mierotubules and endoplasmic reticulum, which were similar to the neutrophil inclusions in shape. Conclusion: Abnormal NMMHC- ⅡA resulted in a inhomogeneous organelle distribu tion within platelets, and it is likely to be an essential factor for maintaining the activation state of the platelets in patients with MYH9-RD.