Due to limited data on the link between gut barrier defects (leaky gut) and neutrophil extracellular traps (NETs) in coronavirus disease 2019 (COVID-19), blood samples of COVID-19 cases—mild (upper respiratory tract symptoms without pneumonia; n = 27), moderate (pneumonia without hypoxia; n = 28), and severe (pneumonia with hypoxia; n = 20)—versus healthy control (n = 15) were evaluated, together with in vitro experiments. Accordingly, neutrophil counts, serum cytokines (IL-6 and IL-8), lipopolysaccharide (LPS), bacteria-free DNA, and NETs parameters (fluorescent-stained nuclear morphology, dsDNA, neutrophil elastase, histone–DNA complex, and myeloperoxidase–DNA complex) were found to differentiate COVID-19 severity, whereas serum (1→3)-β-D-glucan (BG) was different between the control and COVID-19 cases. Despite non-detectable bacteria-free DNA in the blood of healthy volunteers, using blood bacteriome analysis, proteobacterial DNA was similarly predominant in both control and COVID-19 cases (all severities). In parallel, only COVID-19 samples from moderate and severe cases, but not mild cases, were activated in vitro NETs, as determined by supernatant dsDNA, Peptidyl Arginine Deiminase 4, and nuclear morphology. With neutrophil experiments, LPS plus BG (LPS + BG) more prominently induced NETs, cytokines, NFκB, and reactive oxygen species, when compared with the activation by each molecule alone. In conclusion, pathogen molecules (LPS and BG) from gut translocation along with neutrophilia and cytokinemia in COVID-19-activated, NETs-induced hyperinflammation.

Ocular pythiosis is the second most common form of human pythiosis, and the rates of evisceration/enucleation in Thailand are 55–79%. This prospective study was conducted to evaluate treatment outcomes of the combination therapy protocol and the potential use of serum (1→3)-β-glucan (BG) and Pythium insidiosum-specific antibody (Pi-Ab) as an aid to diagnosis and monitoring of ocular pythiosis. Thirty patients were enrolled in the study and 14 (non-globe salvage) required evisceration/enucleation. The globe salvage group was significantly younger, and first ocular surgeries were performed significantly sooner than in the non-globe salvage group. Serum BG and Pi-Ab levels were similar among the 2 groups over time. In vitro susceptibility testing of antifungal agents revealed relatively high minimum inhibitory concentrations and lack of synergistic effect. Serum BG and Pi-Ab would not be useful in diagnosis and monitoring of ocular pythiosis. Until effective antimicrobial agents are discovered, ocular surgeries are still the mainstay therapy in Thailand.

Patients with multiple myeloma (MM) have a diminished immune response to coronavirus disease 2019 (COVID-19) vaccines. Risk factors for an impaired immune response are yet to be determined. We aimed to summarize the COVID-19 vaccine immunogenicity and to identify factors that influence the humoral immune response in patients with MM. Two reviewers independently conducted a literature search in MEDLINE, Embase, ISI Web of Science, Cochrane library, and Clinicaltrials.gov from existence until 24 May 24 2022. (PROSPERO: CRD42021277005). A total of 15 studies were included in the systematic review and 5 were included in the meta-analysis. The average rate (range) of positive functional T-lymphocyte response was 44.2% (34.2%-48.5%) after 2 doses of messenger RNA (mRNA) COVID-19 vaccines. The average antispike antibody response rates (range) were 42.7% (20.8%-88.5%) and 78.2% (55.8%-94.2%) after 1 and 2 doses of mRNA COVID-19 vaccines, respectively. The average neutralizing antibody response rates (range) were 25% (1 study) and 62.7% (53.3%-68.6%) after 1 and 2 doses of mRNA COVID-19 vaccines, respectively. Patients with high-risk cytogenetics or receiving anti-CD38 therapy were less likely to have a humoral immune response with pooled odds ratios of 0.36 (95% confidence interval [95% CI], 0.18, 0.69), I2 = 0% and 0.42 (95% CI, 0.22, 0.79), I2 = 14%, respectively. Patients who were not on active MM treatment were more likely to respond with pooled odds ratio of 2.42 (95% CI, 1.10, 5.33), I2 = 7%. Patients with MM had low rates of humoral and cellular immune responses to the mRNA COVID-19 vaccines. Further studies are needed to determine the optimal doses of vaccines and evaluate the use of monoclonal antibodies for pre-exposure prophylaxis in this population.

SARS-CoV-2 infection results in a broad spectrum of clinical outcomes, ranging from asymptomatic to severe symptoms and death. Most COVID-19 pathogenesis is associated with hyperinflammatory conditions driven primarily by myeloid cell lineages. The long-term effects of SARS-CoV-2 infection post recovery include various symptoms. We performed a longitudinal study of the innate immune profiles 1 and 3 months after recovery in the Thai cohort by comparing patients with mild, moderate, and severe clinical symptoms using peripheral blood mononuclear cells (n = 62). Significant increases in the frequencies of monocytes compared to controls and NK cells compared to mild and moderate patients were observed in severe patients 1–3 months post recovery. Increased polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) were observed in all recovered patients, even after 3 months. Increased IL-6 and TNFα levels in monocytes were observed 1 month after recovery in response to lipopolysaccharide (LPS) stimulation, while decreased CD86 and HLA-DR levels were observed regardless of stimulation. A multiplex analysis of serum cytokines performed at 1 month revealed that most innate cytokines, except for TNFα, IL4/IL-13 (Th2) and IFNγ (Th1), were elevated in recovered patients in a severity-dependent manner. Finally, the myelopoiesis cytokines G-CSF and GM-CSF were higher in all patient groups. Increased monocytes and IL-6- and TNFα-producing cells were significantly associated with long COVID-19 symptoms. These results reveal that COVID-19 infection influences the frequencies and functions of innate immune cells for up to 3 months after recovery, which may potentially lead to some of the long COVID symptoms.

Human pythiosis is a life-threatening human disease caused by Pythium insidiosum . In Thailand, vascular pythiosis is the most common form and carries a mortality rate of 10 to 40%, despite aggressive treatment with radical surgery, antifungal agents, and immunotherapy. Itraconazole and terbinafine have been the mainstay of treatment, until recently, based on case report data showing potential synergistic effects against Brazilian P. insidiosum isolates. However, the synergistic effects of itraconazole and terbinafine against Thai P. insidiosum isolates were not observed.

Neutrophil Extracellular Traps (NETs) are a contributing factor of vascular thrombosis and alveolar damage in COVID-19 patients. As enoxaparin is currently used to inhibit vascular thrombosis, this study aimed to investigate whether enoxaparin also reduced inflammation and NETs in COVID-19 patients. Patients with COVID-19 infection were classified into three groups: mild, moderate, and severe (n = 10 for all groups). Plasma was collected from patients and healthy donors (n = 10). Neutrophils isolated from healthy controls were incubated with COVID-19 or healthy plasma, and with or without enoxaparin pretreatment in vitro. Neutrophils and plasma isolated from patients treated with enoxaparin were also investigated. The levels of inflammatory cytokines and NET products such as dsDNA, NE, MPO–DNA and Histone–DNA complexes in plasma and supernatants were measured using immunofluorescence staining and ELISA kits. The expression of inflammatory signaling genes by neutrophils (RELA, SYK, ERK and PKC) was measured using real-time qPCR. The levels of NET products were elevated in the plasma of COVID-19 patients, particularly in the severe group (p < 0.01). Moreover, plasma from the severe group enhanced NET formation (p < 0.01) from neutrophils in vitro. Enoxaparin pretreatment in vitro decreased plasma-induced NETs in a dose-dependent manner and down-regulated the expression of inflammatory genes (p < 0.05). Patients treated with prophylactic enoxaparin showed lower inflammatory cytokine levels and expression of inflammatory genes (p < 0.05). Increased NETs were associated with the severity of COVID-19 infection, particularly in patients with severe pneumonia, and could be used as biomarkers to assess disease severity. Enoxaparin pretreatment inhibited NETs and reduced the expression of inflammatory cytokines, and these effects mostly persisted in patients treated with prophylactic enoxaparin.