Background

Significant overlap may occur between idiopathic interstitial pneumonia (IIP) and connective tissue diseases (CTDs) that do not meet the established classification criteria for any known CTDs (i.e., occult CTD). Performing minor salivary gland biopsy (MSGB) to detect occult primary Sjogren's syndrome (pSS) in IIP patients is not well studied.

Methods

Consecutive IIP patients underwent MSGB to determine the prevalence of positive MSGB findings. Furthermore, we characterised the clinical, physiological and serological profiles of the MSGB-positive patients. Cox regression models were used to identify independent predictors of survival.

Results

The data of 155 patients with IIP were available for analysis. Sixty patients (38.7%) had positive MSGB findings. Of them, the mean age was 63.3 years, 51.6% were women, usual interstitial pneumonia (UIP) was the predominant pattern (63.3%), and seronegative antibodies (61.6%) were likely. Patients with positive MSGB findings had significantly greater survival than those with negative MSGB findings (p = 0.041). After stratifying the MSGB cohort based on the presence of a UIP pattern, no significant difference in survival was noted between those with positive MSGB-UIP pattern and those with a negative MSGB-UIP pattern (p = 0.231). Multivariate analysis on all UIP patients showed that higher forced vital capacity (p = 0.010) and smoking status (p = 0.035) were independently associated with survival.

Conclusions

A substantial number of IIP patients had underlying occult CTD, highlighting the importance of performing MSGB to identify the salivary component of pSS when evaluating patients with interstitial lung disease of undetermined aetiology.

中文翻译：

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特发性间质性肺炎小唾液腺活检的临床意义

背景

不符合任何已知CTD（即​​隐匿性CTD）的既定分类标准的特发性间质性肺炎（IIP）与结缔组织疾病（CTD）之间可能会出现重大重叠。对IIP患者进行小唾液腺活检（MSGB）以检测隐匿性原发性干燥综合征（pSS）的研究尚未深入研究。

方法

连续的IIP患者接受MSGB以确定MSGB阳性发现的患病率。此外，我们表征了MSGB阳性患者的临床，生理和血清学特征。使用Cox回归模型来确定生存的独立预测因子。

结果

155例IIP患者的数据可供分析。60名患者（38.7％）的MSGB阳性结果。其中平均年龄为63.3岁，女性为51.6％，常见的是间质性肺炎（UIP）（63.3％），而血清反应阴性的抗体很可能为61.6％。MSGB阳性的患者比MSGB阴性的患者生存率更高（p = 0.041）。根据UIP模式的存在对MSGB队列进行分层后，在MSGB-UIP模式为阳性的患者与MSGB-UIP模式为阴性的患者之间，生存率没有显着差异（p = 0.231）。对所有UIP患者的多变量分析显示，较高的强制肺活量（p = 0.010）和吸烟状态（p = 0.035）与生存独立相关。

结论

大量IIP患者具有潜在的隐匿性CTD，突出了在评估病因不明的间质性肺病患者时，进行MSGB鉴别pSS唾液成分的重要性。