Saad Mahnoor, Babar Laila, Khawaja Sheza
Internal Medicine, Howard University Hospital, Washington DC, USA.
Internal Medicine, Allegheny General Hospital, Pittsburgh, USA.
Cureus. 2024 Nov 17;16(11):e73844. doi: 10.7759/cureus.73844. eCollection 2024 Nov.
Human granulocytic anaplasmosis (HGA) is transmitted by the black-legged tick and presents with fever, thrombocytopenia, leukocytopenia, and elevated transaminases. If left untreated, HGA can progress to hemophagocytic lymphohistiocytosis (HLH), which can be fatal. Here, we discuss a case of a woman diagnosed with anaplasmosis who was treated promptly. A 63-year-old female presented with a two-day history of fever and fatigue. She denied any history of hiking but confirmed an avid gardening hobby. She did not report any tick bites or rashes. Upon presentation, she was febrile but hemodynamically stable. Her laboratory results showed elevated liver function tests (LFTs) and bicytopenia, with a white blood cell count (WBC) of 0.77 k/mcL (normal = 4.4-11.3 k/mcL), an absolute neutrophil count (ANC) of 150/µL (normal = >500/µL), and a platelet count of 50 k/mcL (normal = 145-445 k/mcL). Her liver function tests (LFTs) were elevated, including alanine aminotransferase (ALT) of 75 U/L (normal = 0-40 U/L) and aspartate aminotransferase (AST) of 66 U/L (normal = 0-40 U/L). Her lab results had been normal one month prior during routine testing. She was tested for Lyme antibodies, antibodies, and anaplasmosis via a polymerase chain reaction (PCR) test. She was started on doxycycline, and within two days, her counts began to recover. Her Lyme antibody titers and antibody tests were negative, but she tested positive for antibodies, confirming anaplasmosis. She was discharged home, and on follow-up, her WBC had risen to 4.6 k/mcL (normal = 4.4-11.3 k/mcL), and platelets increased to 84 k/mcL (normal = 145-445 k/mcL). Human granulocytic anaplasmosis is a rickettsial disease that typically presents with symptoms such as fatigue, malaise, fever, thrombocytopenia, and leukopenia. It carries a small but significant risk of progressing to HLH if not treated early in its course. Human granulocytic anaplasmosis has a presentation similar to ehrlichiosis and is differentiated based on PCR testing for deoxyribonucleic acid (DNA); however, since treatment is the same for both diseases, patients are often started on doxycycline before confirmatory test results are available. Physicians working in tick-endemic areas must maintain a high suspicion for rickettsial illnesses, as these patients often present with vague symptoms and can be undiagnosed if not properly evaluated.
人粒细胞无形体病（HGA）通过黑腿蜱传播，表现为发热、血小板减少、白细胞减少和转氨酶升高。如果不进行治疗，HGA可进展为噬血细胞性淋巴组织细胞增生症（HLH），这可能是致命的。在此，我们讨论一例被诊断为无形体病且得到及时治疗的女性病例。一名63岁女性出现发热和疲劳症状两天。她否认有徒步旅行史，但确认有热衷于园艺的爱好。她未报告有蜱叮咬或皮疹。就诊时，她发热但血流动力学稳定。她的实验室检查结果显示肝功能检查（LFTs）升高和双细胞减少，白细胞计数（WBC）为0.77k/微升（正常范围=4.4 - 11.3k/微升），绝对中性粒细胞计数（ANC）为150/微升（正常范围>500/微升），血小板计数为50k/微升（正常范围=145 - 445k/微升）。她的肝功能检查（LFTs）升高，包括丙氨酸转氨酶（ALT）为75U/L（正常范围=0 - 40U/L）和天冬氨酸转氨酶（AST）为66U/L（正常范围=0 - 40U/L）。她一个月前的常规检查结果正常。她接受了莱姆抗体、[此处原文缺失一种抗体名称]抗体检测以及通过聚合酶链反应（PCR）检测无形体病。她开始服用多西环素，两天内，她的各项计数开始恢复。她的莱姆抗体滴度和[此处原文缺失一种抗体名称]抗体检测为阴性，但她的[此处原文缺失一种抗体名称]抗体检测呈阳性，确诊为无形体病。她出院回家，随访时，她的白细胞计数升至4.6k/微升（正常范围=4.4 - 11.3k/微升），血小板增加至84k/微升（正常范围=145 - 445k/微升）。人粒细胞无形体病是一种立克次体病，通常表现为疲劳、不适、发热、血小板减少和白细胞减少等症状。如果在病程早期未进行治疗，它发展为HLH的风险虽小但很显著。人粒细胞无形体病的表现与埃立克体病相似，基于脱氧核糖核酸（DNA）的PCR检测进行鉴别；然而，由于两种疾病的治疗方法相同，在确诊测试结果出来之前，患者通常就开始服用多西环素。在蜱虫流行地区工作的医生必须对立克次体病保持高度怀疑，因为这些患者常常表现出模糊的症状，如果评估不当可能无法确诊。
