Department of Thoracic Medicine and Surgery, Lewis Katz School of Medicine, The Lung Center, Temple University School of Medicine, Philadelphia, Pennsylvania, USA.
COPD. 2020 Dec;17(6):619-622. doi: 10.1080/15412555.2020.1812055. Epub 2020 Aug 30.
Alpha 1 antitrypsin deficiency (AATD) is a rarely diagnosed hereditary condition characterized by low alpha 1 antitrypsin (AAT) levels, which can lead to early-onset emphysema due to accelerated degradation of lung tissue. Similar to C-reactive protein (CRP), AAT is an acute phase reactant, meaning that blood levels rise in response to inflammation, injury or infection. Testing AAT levels is essential in the diagnosis of AATD; however, the presence of inflammation at the time of AATD testing can provide a false 'normal' level reading of the patient's baseline AAT levels. Researchers from a US-wide screening program for AATD found that a large number of individuals with AATD variants (particularly with the PI*MZ genotype) presented with elevated CRP levels (≥5 mg/L), suggesting the presence of inflammation. Using a series of calculations, the relationship between AAT and CRP levels was characterized and found to be genotype specific. We have developed a publicly available, easy-to-use online calculator (PredictAAT) that enables the instant calculation of predicted baseline AAT levels in patients exhibiting elevated CRP levels that accounts for specific AATD genotype. There is a need to raise awareness of the importance of simultaneous determination of AAT and CRP levels to aid the accurate diagnosis of patients with AATD. The PredictAAT calculator is therefore a valuable tool for physicians to enhance early disease diagnosis and individualize treatment.
α1-抗胰蛋白酶缺乏症（AATD）是一种罕见的遗传性疾病，其特征是α1-抗胰蛋白酶（AAT）水平降低，这可能导致肺组织加速降解的早发性肺气肿。与 C 反应蛋白（CRP）类似，AAT 是一种急性时相反应物，这意味着在炎症、损伤或感染时血液水平会升高。检测 AAT 水平对 AATD 的诊断至关重要；然而，在进行 AATD 检测时存在炎症会导致患者基础 AAT 水平的假“正常”读数。来自美国一项 AATD 筛查计划的研究人员发现，大量 AAT 变异体（尤其是 PI*MZ 基因型）患者的 CRP 水平升高（≥5mg/L），这表明存在炎症。通过一系列计算，研究人员描述了 AAT 和 CRP 水平之间的关系，并发现其具有基因型特异性。我们开发了一个易于使用的在线计算器（PredictAAT），该计算器可以即时计算出 CRP 水平升高的患者的预测基础 AAT 水平，同时考虑了特定的 AATD 基因型。因此，需要提高对同时测定 AAT 和 CRP 水平以帮助准确诊断 AATD 患者的重要性的认识。PredictAAT 计算器是医生增强早期疾病诊断和个体化治疗的有价值的工具。
