Ndlovu Ntombizodwa, Rees David, Lakhoo Deepna Govind, Murray Jill
School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
National Health Laboratory Service, Johannesburg, South Africa.
ERJ Open Res. 2025 Sep 8;11(5). doi: 10.1183/23120541.01103-2024. eCollection 2025 Sep.
Lymph node silicosis (LNS) may be found when investigating lung and mediastinal diseases. Co-occurrence of LNS and pulmonary silicosis (PS) has been described but no studies have investigated the diagnostic accuracy of LNS for PS, the aim of this study.
This cross-sectional study included South African miners with exclusive gold-mining employment who had autopsy examinations from 1975 to 2018. Routinely recorded pathologist-diagnosed LNS and PS and occupational histories were retrieved from the PATHAUT database. Pulmonary silicosis was the reference standard. Sensitivity, specificity, positive and negative predictive values (PPV and NPV) and summary diagnostic accuracy were calculated overall and by PS severity and employment duration.
Of the 69 802 miners, the prevalences of LNS and PS were 39.2% (n=27 373) and 17.7% (n=12 345), respectively. There were 24.1% false-positive LNS tests. Sensitivity was 85.2% (95% CI 84.6-85.6), but specificity was lower (70.7%, 95% CI 70.3-71.0). The PPV and NPV were 38.4% (95% CI 37.9-39.0) and 95.7% (95% CI 95.5-95.9), respectively. Sensitivity increased and specificity decreased with increasing employment duration.
Our findings are consistent with LNS occurring at concentrations of respirable crystalline silica too low to cause PS and possibly being a portent of PS. LNS had deficits as a diagnostic test for PS. The low PPV raises uncertainty about the presence of PS in patients with LNS. LNS may perform better in populations with higher prevalence of silicosis, for example in patients with clinically suspected PS.
在对肺部和纵隔疾病进行调查时可能会发现淋巴结矽肺（LNS）。LNS与肺矽肺（PS）的共存已有报道，但尚无研究调查LNS对PS的诊断准确性，这是本研究的目的。
这项横断面研究纳入了1975年至2018年期间接受尸检的南非金矿工人。从PATHAUT数据库中检索了病理学家常规诊断的LNS和PS以及职业病史。肺矽肺为参考标准。总体上以及按PS严重程度和工作年限计算敏感性、特异性、阳性和阴性预测值（PPV和NPV）以及综合诊断准确性。
在69802名矿工中，LNS和PS的患病率分别为39.2%（n = 27373）和17.7%（n = 12345）。LNS检测有24.1%的假阳性。敏感性为85.2%（95%CI 84.6 - 85.6），但特异性较低（70.7%，95%CI 70.3 - 71.0）。PPV和NPV分别为38.4%（95%CI 37.9 - 39.0）和95.7%（95%CI 95.5 - 95.9）。随着工作年限增加，敏感性增加而特异性降低。
我们的研究结果与LNS在可吸入结晶二氧化硅浓度过低以至于不会导致PS的情况下发生且可能是PS的预兆一致。LNS作为PS的诊断测试存在不足。低PPV增加了LNS患者中PS存在情况的不确定性。LNS在矽肺患病率较高的人群中可能表现更好，例如临床疑似PS的患者。
