Surfactant protein D: a useful marker for differentiation of drug-induced pneumonia and bacterial pneumonia

Abstract

Background Drug-induced pneumonia (d-pneumonia) and bacterial pneumonia (b-pneumonia) are often difficult to differentiate; therefore, this study examined the possibility of differentiating them using serum biomarkers. Methods The study included 22 and 16 patients diagnosed with b- and d-pneumonia, respectively, at our institution or affiliated institutions. For d-pneumonia, the causative drug was minocycline hydrochloride in four patients, gefitinib in two patients, nivolumab in two patients, pembrolizumab in two patients, sulfasalazine in two patients, loxoprofen in one patient, Bouiougitou in one patient, edoxaban tosilate hydrate in one patient, and abemaciclib in one patient. White blood cell (WBC), C-reactive protein (CRP), Krebs von den Lungen-6 (KL-6), surfactant protein (SP)-D, and SP-A levels were measured in each patient and compared between the groups. Results Significant differences were noted in the WBC and SP-D levels between the two groups (P < 0.05, P < 0.001), but not in the CRP, KL-6, or SP-A levels. Conclusion The study results suggest that SP-D is a useful marker for differentiating b-pneumonia and d-pneumonia.

Clinicoradiological course of abemaciclib-induced pneumonitis with histology findings

“…KL-6 and SP-D levels were positive during treatment with abemaciclib prior to consultation with us and improved with treatment (figure 2). KL-6 is an MUC1 mucin protein and has been observed in adenocarcinoma of various cancer cell lines, including breast cancer,10 whereas SP-D is considered a useful marker of drug-induced pneumonitis 11. Since the severity of abemaciclib-induced pneumonitis ranges from mild to fatal, monitoring these multiple diagnostic arms and collaborative consultation with pulmonologists may be highly effective in preventing drug-induced pneumonitis.…”

Serum Biomarkers in a Radiological Pattern of Non-Fibrotic Hypersensitivity Pneumonitis: Implications for Mechanistic Difference and Differential Diagnosis

“…KL-6 is produced by actively regenerating type II alveolar epithelial cells, whereas SP-D is produced by type II alveolar epithelial cells once they have matured and regenerated [ 29 ]. In addition, the activation of a specific enzyme is necessary to cleave KL-6 from the cell membrane, and it is thought that more severe injury must occur to increase circulating KL-6 levels [ 30 ]. These functional differences may explain the differences in serum concentrations.…”

“…Some studies on serum biomarkers in DRP have reported that absolute levels at the onset or changes from the baseline of KL-6 can predict the clinical outcomes of DRP [ 14 , 37 ]. KL-6, SP-D, and SP-A can be different and not associated, depending on the situation in DRP [ 30 , 38 ]. There have been no reports that have focused on serum biomarkers in DRP-HP.…”