[Analysis of clinical presentation and genetic characteristics of malignant infantile osteopetrosis]

Objective: To investigate the clinical presentation and genetic characteristics of malignant infantile osteopetrosis. Methods: This was a retrospective case study. Thirty-seven children with malignant infantile osteopetrosis admitted into Beijing Children's Hospital from January 2013 to September 2022 were enrolled in this study. According to the gene mutations, the patients were divided into the CLCN7 group and the TCIRG1 group. Clinical characteristics, laboratory tests, and prognosis were compared between two groups. Wilcoxon test or Fisher exact test were used in inter-group comparison. The survival rate was estimated with the Kaplan-Meier method and the Log-Rank test was used to compare the difference in survival between groups. Results: Among the 37 cases, there were 22 males and 15 females. The age of diagnosis was 0.5 (0.2, 1.0) year. There were 13 patients (35%) and 24 patients (65%) with mutations in CLCN7 and TCIRGI gene respectively. Patients in the CLCN7 group had an older age of diagnosis than those in the TCIRGI group (1.2 (0.4, 3.6) vs. 0.4 (0.2, 0.6) years, Z=-2.60, P=0.008). The levels of serum phosphorus (1.7 (1.3, 1.8) vs. 1.1 (0.8, 1.6) mmol/L, Z=-2.59, P=0.010), creatine kinase isoenzyme (CK-MB) (457 (143, 610) vs. 56 (37, 82) U/L, Z=-3.38, P=0.001) and the level of neutrophils (14.0 (9.9, 18.1) vs. 9.2 (6.7, 11.1) ×109/L, Z=-2.07, P=0.039) at diagnosis were higher in the CLCN7 group than that in the TCIRG1 group. However, the level of D-dimer in the CLCN7 group was lower than that in the TCIRGI group (2.7 (1.0, 3.1) vs. 6.3 (2.5, 9.7) μg/L, Z=2.83, P=0.005). After hematopoietic stem cell transplantation, there was no significant difference in 5-year overall survival rate between the two groups (92.3%±7.4% vs. 83.3%±7.6%, χ²=0.56, P=0.456). Conclusions: TCIRGI gene mutations are more common in children with osteopetrosis. Children with TCIRGI gene mutations have younger age, lower levels of phosphorus, CK-MB, and neutrophils and higher level of D-dimer at the onset. After hematopoietic stem cell transplantation, patients with CLCN7 or TCIRGI gene mutations have similar prognosis.

Exosomes mediate Coxsackievirus B3 transmission and expand the viral tropism

Specific virus-receptor interactions are important determinants in viral host range, tropism and pathogenesis, influencing the location and initiation of primary infection as well as viral spread to other target organs/tissues in the postviremic phase. Coxsackieviruses of Group B (CVB) and its six serotypes (CVB1-6) specifically interact with two receptor proteins, coxsackievirus-adenovirus receptor (CAR) and decay-accelerating factor (DAF), and cause various lesions in most permissive tissues. However, our previous data and other studies revealed that virus receptor-negative cells or tissues can be infected with CVB type 3 (CVB3), which can also effectively replicate. To study this interesting finding, we explored the possibility that exosomes are involved in CVB3 tropism and that exosomes functionally enhance CVB3 transmission. We found that exosomes carried and delivered CVB3 virions, resulting in efficient infection in receptor-negative host cells. We also found that delivery of CVB3 virions attached to exosomes depended on the virus receptor CAR. Importantly, exosomes carrying CVB3 virions exhibited greater infection efficiency than free virions because they accessed various entry routes, overcoming restrictions to viral tropism. In vivo experiments demonstrated that inhibition of exosome coupling with virions attenuated CVB3-induced immunological system dysfunction and reduced mortality. Our study describes a new mechanism in which exosomes contribute to viral tropism, spread, and pathogenesis.

COVID-19 Clinical Trials Registered Worldwide for Drug Intervention: An Overview and Characteristic Analysis

OBJECTIVE

This study aims to comprehensively evaluate the characteristics of clinical drug trials to facilitate the collection of evidence for COVID-19 drug treatments.

METHODS

A retrospective analysis of 910 trials retrieved on August 7, 2020.

RESULTS

A total of 910 registered clinical trials with at least one drug intervention were evaluated. The number of registrations (32.4%, 295) from the United States accounted for nearly one-third of the total and far exceeded that of other countries individually. Furthermore, the peak number of trials were registered in April (34.3%, 312). Over half of the trials (51.2%, 466) are in the recruitment phase, and only 4.2% (38) of the trials have been completed. The median (interquartile range) estimated enrollment is 127 (59, 365). In 39% (355) of trials, the estimated enrollment is less than 100 participants. A total of 94.5% (790) of the trials use randomization in the allocation, 82.7% (753) use a parallel intervention mode, and 52.2% (475) use masking. A total of 287 drug names have been standardized and mapped. "Hydroxychloroquine" is the leading drug among the registered trials (7.47%, 68). Among the main countries contributing to investigations on "hydroxychloroquine", the United States ranks first with 36.76% (25) of the trials.

CONCLUSION

The designs of COVID-19 clinical drug trials have greatly improved in terms of the implementation of randomization and, particularly, blinding methods. In terms of drug reuse, the number of drug types has greatly increased, and hundreds of drugs have been used for efficacy screening. The emergence of large-sample registration trials is expected to address the uncertainty regarding the current clinical efficacy of some drugs.

The Correlation Between Clinical Features and Viral RNA Shedding in Outpatients With COVID-19

BACKGROUND

Patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can shed virus, thereby causing human-to-human transmission, and the viral RNA shedding is commonly used as a proxy measure for infectivity.

METHODS

We retrospectively reviewed confirmed cases of COVID-19 who attended the fever clinic of Wuhan Union Hospital from January 14 to February 24. In terms of the viral RNA shedding (median values) at first visit, patients were divided into a high-viral RNA shedding group and a low-viral RNA shedding group. Univariate and multivariate logistic regression analysis were performed to investigate the correlation between viral RNA shedding and clinical features.

RESULTS

A total of 918 consecutive COVID-19 patients were enrolled, and severe patients made up 26.1%. After univariate and multivariate logistic regression, advanced age (odds ratio [OR], 1.02; 95% CI, 1.01-1.03; P = .001), having severe chronic diseases (OR, 1.44; 95% CI, 1.03-2.01; P = .04), and severe illness (OR, 1.60; 95% CI, 1.12-2.28; P = .01) were independent risk factors for high viral RNA shedding. Shorter time interval from symptom onset to viral detection was a protective factor for viral RNA shedding (OR, 0.97; 95% CI, 0.94-0.99; P = .01). Compared with mild patients, severe patients have higher virus shedding over a long period of time after symptom onset (P = .01).

CONCLUSIONS

Outpatients who were old, had severe illness, and had severe underlying diseases had high viral RNA shedding.