Molecular Characterization of Seasonal Influenza A and B from Hospitalized Patients in Thailand in 2018–2019

Influenza viruses continue to be a major public health threat due to the possible emergence of more virulent influenza virus strains resulting from dynamic changes in virus adaptability, consequent of functional mutations and antigenic drift in surface proteins, especially hemagglutinin (HA) and neuraminidase (NA). In this study, we describe the genetic and evolutionary characteristics of H1N1, H3N2, and influenza B strains detected in severe cases of seasonal influenza in Thailand from 2018 to 2019. We genetically characterized seven A/H1N1 isolates, seven A/H3N2 isolates, and six influenza B isolates. Five of the seven A/H1N1 viruses were found to belong to clade 6B.1 and were antigenically similar to A/Switzerland/3330/2017 (H1N1), whereas two isolates belonged to clade 6B.1A1 and clustered with A/Brisbane/02/2018 (H1N1). Interestingly, we observed additional mutations at antigenic sites (S91R, S181T, T202I) as well as a unique mutation at a receptor binding site (S200P). Three-dimensional (3D) protein structure analysis of hemagglutinin protein reveals that this unique mutation may lead to the altered binding of the HA protein to a sialic acid receptor. A/H3N2 isolates were found to belong to clade 3C.2a2 and 3C.2a1b, clustering with A/Switzerland/8060/2017 (H3N2) and A/South Australia/34/2019 (H3N2), respectively. Amino acid sequence analysis revealed 10 mutations at antigenic sites including T144A/I, T151K, Q213R, S214P, T176K, D69N, Q277R, N137K, N187K, and E78K/G. All influenza B isolates in this study belong to the Victoria lineage. Five out of six isolates belong to clade 1A3-DEL, which relate closely to B/Washington/02/2009, with one isolate lacking the three amino acid deletion on the HA segment at position K162, N163, and D164. In comparison to the B/Colorado/06/2017, which is the representative of influenza B Victoria lineage vaccine strain, these substitutions include G129D, G133R, K136E, and V180R for HA protein. Importantly, the susceptibility to oseltamivir of influenza B isolates, but not A/H1N1 and A/H3N2 isolates, were reduced as assessed by the phenotypic assay. This study demonstrates the importance of monitoring genetic variation in influenza viruses regarding how acquired mutations could be associated with an improved adaptability for efficient transmission.     

Serum antioxidant levels and nutritional status in early and advanced stage lung cancer patients

ObjectiveMalnutrition frequently occurs in lung cancer patients. We aimed to determine nutritional status and antioxidant and mineral levels in Thai patients with lung cancer.MethodsA prospective study with matched case-control was conducted. Nutritional status was assessed by body mass index (BMI) and subjective global assessment (SGA). Eastern Cooperative Oncology Group (ECOG) performance status was used to assess the performance. The serum antioxidant and mineral levels were determined.ResultsForty-nine patients with a mean age of 58.8 (range, 35-82) who were first diagnosed with lung cancer were enrolled. They were compared with 60 healthy controls, and levels of retinol, α-tocopherol, β-carotene, lycopene, β-cryptoxanthin, selenium, and zinc were lower (P < 0.05). However, peroxidase activity was higher (P = 0.002) in patients. Selenium levels were higher in early stage compared to advanced stage patients (P = 0.041). Overweight patients had higher selenium levels (0.04 mg/L) than normal BMI patients (β = 0.04, P = 0.035). Patients with SGA class C had lower selenium levels (0.03 mg/L) than those with class A (β = ?0.03, P = 0.035). The poorer ECOG performance patients had significantly lower β-carotene (β = ?0.192, P = 0.003) and selenium (β = ?0.031, P = 0.011) levels compared with those with good ECOG performance status.ConclusionsSignificantly lower levels of antioxidants and selenium were found in lung cancer patients compared to healthy controls. Levels of some antioxidants and minerals differed among categories of BMI, SGA categories, or ECOG performance status. These findings may be helpful for further studies, such as the effect of nutritional supplementation on clinical outcomes.