Real-world utility of serological tests in patients with suspected scrub typhus in the Republic of Korea:A single-center,retrospective,observational study

Objective:Serological tests are widely used for scrub typhus diagnosis;however,their limitations are evident.This study aims to assess their practical value in clinical settings.Methods:We analyzed the data of adult patients with suspected scrub typhus who visited a tertiary care hospital in the Republic of Korea from September to December from 2019 to 2021.The included patients had an acute fever and at least one of the following ten secondary findings:myalgia,skin rash,eschar,headache,thrombocytopenia,increased liver enzyme levels,lymphadenopathy,hepatomegaly,splenomegaly,and pleural effusion.The diagnoses were grouped as scrub typhus or other diseases by two infectious disease physicians.Results:Among 136 patients who met the eligibility criteria,109 had scrub typhus and 27 had different diseases.Single and paired total antibodies using immunofluorescence assay(IFA),and total antibodies using immunochromatography-based rapid diagnostic testing(ICT)were measured in 98%,22%,and 75%of all patients,respectively.Confirmation using paired samples for scrub typhus was established at a median of 11[interquartile range(IQR)10-16]days following the first visit.Among the 82 admitted patients,the median admission time was 9(IQR 7-13)days.According to IFA,58(55%)patients with scrub typhus had total immunoglobulin titers≥1:320,while 23(85%)patients with other disease had titers<1:320.Positive ICT results were observed in 64(74%)patients with scrub typhus and 10(67%)patients with other diseases showed negative ICT results.Conclusions:Serological testing for scrub typhus is currently insufficient for decision-making in clinical practice.

Clinical Response to Treatment of Central Nervous System Tuberculosis in Non-Human Immunodeficiency Virus-Infected Adolescents and Adults

Introduction: More than half of patients with central nervous system tuberculosis (CNS TB) die or are left with severe neurological deficits despite receiving anti-TB treatment. Aims of the study: This study examined risk factors associated with poor response to initial treatment with four anti-TB drug regimens or three drug regimens with steroids as adjuvant therapy. Methods: This study analyzed medical records from two tertiary hospitals in Busan, Korea, between January 2009 and March 2012. The subjects were non-human immunodeficiency virus (HIV)-infected patients aged ≥16 years with clinical CNS TB. The subjects were divided into two groups according to response to treatment. Results: In totally, 52 patients with CNS TB were included. Of these, 14 (26%) and 38 (73%) showed poor and good responses, respectively. Of the patients with poor response, nine had stage III disease (64.3%) according to the British Medical Research Council (BMRC) staging system. A significantly higher proportion was seen in the good response group (p < 0.05). Patients with positive cerebrospinal fluid (CSF) acid-fast bacillus (AFB) culture, positive sputum AFB culture, positive CSF TB polymerase chain reaction (PCR) results, and brain tuberculoma had poorer responses (p < 0.05). Multivariate analysis to determine risk factors associated with poor response to anti-TB therapy revealed that a poor response was associated with stage III clinical signs upon diagnosis (odds ratio [OR] 32.122;95% confidence interval [CI] 2.221 - 464.605), positive sputum AFB culture (OR 13.624;95% CI 1.066 - 174.149), and tuberculoma on brain images (OR 45.714;95% CI 1.893 - 1104.018). Conclusions: The results demonstrate the importance of identifying the severity of CNS TB and promptly administering anti-TB drugs. It is necessary to perform drug susceptibility testing for anti-TB drugs. Further studies are needed to confirm the correlations between risk factors associated with poor response and anti-TB drug resistance and the other risk factors.

Exosome-guided direct reprogramming of tumor-associated macrophages from protumorigenic to antitumorigenic to fight cancer

Highly immunosuppressive tumor microenvironment containing various protumoral immune cells accelerates malignant transformation and treatment resistance.In particular,tumor-associated macrophages(TAMs),as the predominant infiltrated immune cells in a tumor,play a pivotal role in regulating the immunosuppressive tumor microenvironment.As a potential therapeutic strategy to counteract TAMs,here we explore an exosome-guided in situ direct reprogramming of tumor-supportive M2-polarized TAMs into tumor-attacking M1-type macrophages.Exosomes derived from M1-type macrophages(M1-Exo)promote a phenotypic switch from anti-inflammatory M2-like TAMs toward pro-inflammatory M1-type macrophages with high conversion efficiency.Reprogrammed M1 macrophages possessing protein-expression profiles similar to those of classically activated M1 macrophages display significantly increased phagocytic function and robust cross-presentation ability,potentiating antitumor immunity surrounding the tumor.Strikingly,these M1-Exo also lead to the conversion of human patient-derived TAMs into M1-like macrophages that highly express MHC class II,offering the clinical potential of autologous and allogeneic exosome-guided direct TAM reprogramming for arming macrophages to join the fight against cancer.