Divisions of Hematology, Adnan Menderes University Medical Faculty, 09100 Aydin, Turkey.
Rheumatol Int. 2012 Jan;32(1):269-71. doi: 10.1007/s00296-010-1747-0. Epub 2011 Jan 18.
Thrombocytosis is an important laboratory finding in rheumatoid arthritis (RA) and it has a correlation with disease activity. Janus kinase 2 valin 617 phenylalanine (JAK2V617F) mutation has gained importance in the diagnosis of myeloproliferative diseases recently. There is no published report in literature on the association between RA and JAK2V617F-positive essential thrombocythemia (ET). In this report, we present a JAK2V617F-positive ET case that had RA. A 57-year-old male patient was diagnosed with RA according to the criteria of American College of Rheumatology (ACR), whose complaint was of pain in the hands and morning stiffness lasting for about 2 h. The patient was evaluated for thrombocytosis because he was in remission and suffering persistent thrombocytosis under treatment. After excluding the causes of secondary thrombocytosis, bone marrow aspiration and biopsy was performed. On peripheral blood and bone marrow PCR examination, the patient was detected to be JAK2V617F positive heterozygously and diagnosed with ET. As a conclusion, mild-moderate thrombocytosis is frequent in RA; however, ET can be diagnosed by JAK2V617F evaluation in peripheral blood in thrombocytosis, especially when platelet count is more than 1 million/ml and when persisting thrombocytosis is detected in RA remission.
血小板增多症是类风湿关节炎（RA）中的一个重要实验室发现，与疾病活动度相关。Janus 激酶 2 缬氨酸 617 苯丙氨酸（JAK2V617F）突变最近在骨髓增殖性疾病的诊断中变得重要。目前，文献中尚无 RA 和 JAK2V617F 阳性原发性血小板增多症（ET）之间关联的报道。在本报告中，我们介绍了一例伴有 RA 的 JAK2V617F 阳性 ET 病例。一名 57 岁男性患者根据美国风湿病学会（ACR）标准被诊断为 RA，其主要症状为手部疼痛和晨僵，持续约 2 小时。由于该患者处于缓解期，但在治疗过程中持续出现血小板增多，因此评估其出现血小板增多的原因。在排除继发性血小板增多症的原因后，进行了骨髓抽吸和活检。外周血和骨髓 PCR 检查发现患者 JAK2V617F 杂合阳性，诊断为 ET。总之，RA 患者中常出现轻中度血小板增多症；然而，在血小板增多症中，特别是当血小板计数超过 100 万/ml 且在 RA 缓解期检测到持续血小板增多症时，可以通过外周血 JAK2V617F 评估来诊断 ET。
