Antibody responses to SARS-CoV-2 in patients with COVID-19.

We report acute antibody responses to SARS-CoV-2 in 285 patients with COVID-19. Within 19 days after symptom onset, 100% of patients tested positive for antiviral immunoglobulin-G (IgG). Seroconversion for IgG and IgM occurred simultaneously or sequentially. Both IgG and IgM titers plateaued within 6 days after seroconversion. Serological testing may be helpful for the diagnosis of suspected patients with negative RT-PCR results and for the identification of asymptomatic infections.

Clinical significance of serum transforming growth factor-ß1 in lung cancer.

BACKGROUND: Transforming growth factor-ß1 (TGF-ß1) plays a critical role in human cancer development. Present study aimed to explore the clinical significance of serum TGF-ß1 levels in patients with lung cancer and analyze the relationship between TGF-ß1 and existing tumor markers for lung cancer. METHODS: Serum was collected from 118 patients with lung cancer and 40 healthy volunteers. Serum TGF-ß1 levels were measured by enzyme-linked immunosorbent assay (ELISA), and the association with various clinical characteristics was analyzed. The diagnostic value of TGF-ß1 was assessed alone and in combination with existing tumor markers for lung cancer. RESULTS: Serum TGF-ß1 levels were significantly higher in patients with lung cancer compared to healthy volunteers [0.6 × 10(5) (0.4 × 10(5), 0.9 × 10(5))pg/ml vs 0.5 × 10(5) (0.3 × 10(5), 0.7 × 10(5))pg/ml, P=0.040]. Although there was a positive correlation between serum TGF-ß1 levels and advanced stages, the significant difference was not found between early stages and advanced stages (P=0.116). The ability of serum TGF-ß1 to discriminate lung cancer at a cutoff value of 79,168 pg/ml exhibited sensitivity of 30.6% and specificity of 97.5%. Serum TGF-ß1 levels were correlated to cytokeratin fragment 21-1 (CYFRA21-1; R=0.308, P=0.020) and neuron-specific enolase (NSE; R=0.558, P=0.003). The diagnostic accuracy rates for the existing lung-tumor markers, as SCC, CYFRA21-1, and NSE, were increased from 20.0%, 34.6%, and 45.9% to 48.9%, 51.7%, and 54.5%, respectively by the inclusion of serum TGF-ß1 levels. CONCLUSION: Quantification of serum TGF-ß1 levels by ELISA may provide a novel complementary tool for the clinical diagnosis of lung cancer.

Clinical significance of serum mitochondrial DNA in lung cancer.

OBJECTIVES: The aim of the study was to investigate the clinical significance of serum mitochondrial DNA (mtDNA) in lung cancer. DESIGN AND METHODS: Serum mtDNA from 65 lung cancer patients, 20 patients with benign lung diseases and 55 healthy individuals was quantified using real-time fluorescent quantitative polymerase chain reaction (FQ-PCR). Data were analyzed using statistical software SPSS 13.0. RESULTS: Serum mtDNA levels in lung cancer patients were significantly higher, compared to those in patients with benign lung diseases and healthy individuals (u=108, p=0.000; u=293, p=0.000), and closely associated with TNM stage (p=0.01). The use of serum mtDNA facilitated detection of lung cancer at a cutoff value of 0.74×104 copies/µL with a sensitivity of 86.2% and specificity of 80.7%. However, serum mtDNA levels were not associated with patient age, gender, histological type, and lymph node metastasis (p>0.05). CONCLUSIONS: Quantification of serum mtDNA using FQ-PCR potentially serves as a novel complementary tool to improve the clinical screening and detection of lung cancer.

Quantification of serum HBXAP DNA in lung cancer patients by quantitative fluorescent polymerase chain reaction.

Hepatitis B virus x associated protein (HBXAP), as a subunit of chromatin remodeling and spacing factor, plays a critical role in cancer development through gene amplification. In this study, we aimed to quantify the levels of serum HBXAP DNA, to analyze and compare its diagnostic value with existing clinical parameters in lung cancer, and to potentially provide a novel tumor marker for lung cancer. Serum HBXAP DNA from 65 lung cancer patients and 20 healthy controls was quantified using real-time fluorescent quantitative polymerase chain reaction (FQ-PCR) analysis. The data were analyzed by statistical software SPSS 13.0. We found that serum HBXAP DNA levels in lung cancer patients were higher compared to healthy controls (u = 219.0, p = 0.001) and were closely associated with TNM stage and lymph node metastasis (p = 0.015 and p = 0.016, respectively). However, serum HBXAP DNA levels were not associated with patient age, gender, smoking status, histological type, or tumor size (p > 0.05). We identified a sensitivity of 61.9 % and a specificity of 93.7 % for the ability of HBXAP DNA levels to detect lung cancer at a cutoff value of 1,557.6 copies/µl. The sensitivity for existing lung-tumor markers, such as squamous cell carcinoma antigen, cytokeratin fragment 21-1, and neuron specific enolase, was increased from 35.7 %, 53.5 %, and 56.0 % to 75.0 %, 86.0 %, and 80.0 %, respectively, by inclusion of serum HBXAP DNA. Taken together, quantification of serum HBXAP DNA by FQ-PCR could potentially serve as a novel complementary tool for the clinical screening and detection of lung cancer.