A variant of RAG1 gene identified in severe combined immunodeficiency: a case report.

BACKGROUND: The recombination-activating gene 1 (RAG1) protein is essential for the V (variable)-D (diversity)-J (joining) recombination process. Mutations in RAG1 have been reported to be associated with several types of immune disorders. Typical clinical features driven by RAG1 variants include persistent infections, severe lymphopenia, and decreased immunoglobulin levels . CASE PRESENTATION: In this study, a 2-month-24-days-old infant with recurrent fever was admitted to our hospital with multiple infections and absence of T and B lymphocytes. The infant was diagnosed with severe combined immunodeficiency (SCID). A homozygous variation c.2147G>A (NM_000448.2: exonme2: c.2147G>A (p.Arg716Gln)) was identified in the RAG1 gene using whole-exome sequencing and Sanger sequencing. The predicted 3D structure of variant RAG1 indicated altered protein stability. Additionally, decreased expression of variant RAG1 gene was detected at both the mRNA and protein levels. CONCLUSIONS: Our study identified a novel homozygous variant in RAG1 gene that causes SCID. This finding expands the variant spectrum of RAG1 in SCID and provides further evidence for the clinical diagnosis of SCID.

Effects of microRNA-101-3p on predicting pediatric acute respiratory distress syndrome and its role in human alveolar epithelial cell.

Pediatric acute respiratory distress syndrome (PARDS) is a severe form of respiratory failure associated with high mortality among children. The objective of this study is reported to explore the clinical function and molecular roles of microRNA-101-3p (miR-101-3p) in PARDS. The levels of miR-101-3p and mRNA levels of SRY-related high-mobility group box 9 (Sox9) were measured by quantitative reverse transcription polymerase chain reaction (RT-qPCR). Additionally, the diagnostic role of miR-101-3p was identified by using the Receiver operating characteristic (ROC) curve. The cell proliferation and apoptosis were examined through Cell Counting Kit-8 (CCK-8) assay and flow cytometry. To detect inflammation in cells, enzyme-linked immunosorbent assays (ELISA) were performed. The target gene of miR-101-3p was confirmed through data obtained from the luciferase activity. In patients with PARDS, miR-101-3p expression was decreased. Moderate and severe PARDS patients had lower levels of miR-101-3p than mild PARDS patients. The inflammatory progression was related to the aberrant expression of miR-101-3p in all PARDS children. MiR-101-3p was highly predictive for the detection of children with PARDS. In addition, miR-101-3p might protect A549 cells from abnormal proliferation, apoptosis, and inflammation caused by lipopolysaccharide (LPS). Sox9 might be a target gene of miR-101-3p and increased mRNA expression of Sox9 in LPS-treated A549 cells was inhibited by overexpression of miR-101-3p. Ultimately, this study suggested that reduced expression of miR-101-3p plays a role in PARDS, providing a novel angle to study the disease.

[Application of double plasma molecular adsorption system in children with acute liver failure].

OBJECTIVE: To study the efficacy and safety of double plasma molecular absorption system (DPMAS) in the treatment of pediatric acute liver failure (PALF). METHODS: A prospective analysis was performed on the medical data of children with PALF who were hospitalized in the Intensive Care Unit (ICU), Hunan Children's Hospital, from March 2018 to June 2020. The children were randomly divided into two groups:plasma exchange group (PE group) and DPMAS group (n=18 each). The two groups were compared in terms of clinical indices after treatment, laboratory markers before and after treatment, and adverse events after treatment. RESULTS: Compared with the PE group, the DPMAS group had a significantly lower number of times of artificial liver support therapy and a significantly shorter duration of ICU stay (P < 0.05), while there was no significant difference in the 12-week survival rate between the two groups (P > 0.05). There was no significant difference in laboratory markers between the two groups before treatment (P > 0.05). After treatment, both groups had reductions in the levels of total bilirubin, interleukin-6, and tumor necrosis factor-α, and the DPMAS group had significantly greater reductions than the PE group (P < 0.05). Both groups had a significant reduction in alanine aminotransferase (P < 0.05), while there was no significant difference between the two groups (P > 0.05). The PE group had a significant increase in albumin, while the DPMAS group had a significant reduction in albumin (P < 0.05). The PE group had a significant reduction in prothrombin time, while the DPMAS group had a significant increase in prothrombin time (P < 0.05). There was no significant difference between the two groups in the rebound rate of total bilirubin and the overall incidence rate of adverse events after treatment (P > 0.05). CONCLUSIONS: DPMAS is safe and effective in the treatment of PALF and can thus be used as an alternative to artificial liver support therapy.

[Clinical application of blood purification in treatment of severe adenovirus pneumonia].

OBJECTIVE: To study the role of blood purification in the treatment of severe adenovirus pneumonia. METHODS: A total of 57 children with severe adenovirus pneumonia who underwent mechanical ventilation from February to June, 2019, were enrolled. According to whether blood purification was performed, they were divided into a purification group with 22 children and a conventional group with 35 children. Related clinical indices were collected, including duration of fever, duration of mechanical ventilation, length of stay in the intensive care unit (ICU), and mortality rate. The purification group was analyzed in terms of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) before blood purification and at 48 hours after blood purification, as well as stroke volume variation (SVV), thoracic fluid content (TFC), arterial partial pressure of oxygen/fraction of inhaled oxygen (P/F) value, and partial pressure of carbon dioxide (PCO2) before blood purification and at 6, 12, 24, and 48 hours after blood purification. RESULTS: Compared with the conventional group, the purification group had significantly shorter duration of fever, duration of mechanical ventilation, and length of stay in the ICU (P<0.05), and there was no significant difference in the mortality rate between the two groups (P>0.05). The purification group had significant reductions in IL-6 and TNF-α after blood purification, (P<0.05) and significant reductions in SVV and TFC at 12, 24, and 48 hours after blood purification (P<0.01), as well as a significant increase in P/F value and a significant reduction in PCO2 at 6, 12, 24, and 48 hours after blood purification (P<0.01). CONCLUSIONS: Blood purification as an auxiliary therapy can effectively improve the clinical symptoms of children with severe adenovirus pneumonia, and is thus an option for the treatment of severe adenovirus pneumonia in children.

[Clinical features of severe type 7 adenovirus pneumonia: an analysis of 45 cases].

OBJECTIVE: To study the clinical features of severe type 7 adenovirus pneumonia in children. METHODS: A retrospective analysis was performed for the clinical data of children who were diagnosed with severe type 7 adenovirus pneumonia from February to June, 2019. RESULTS: Among the 45 children, the male/female ratio was 3:2 and the median age was 14 months. All children had repeated fever, cough, and pulmonary moist rales, and the mean duration of fever was 14±4 days. The median time from fever to dyspnea was 8 days, and the time from fever to mechanical ventilation was 11.6±2.5 d. There was no significant increase in white blood cell count, with neutrophils as the main type. There were slight reductions in hemoglobin and albumin, while platelet and fibrinogen remained normal. There were increases in aspartate aminotransferase, lactate dehydrogenase, procalcitonin, and C-reaction protein. The detection rate of mixed pathogens was 84%. Effusion in both lungs was the major change on chest imaging (64%). Bronchoscopic manifestations were endobronchitis, tracheomalacia, and plastic bronchitis. The incidence rate of respiratory complications was 100%, and extrapulmonary complications mainly involved the circulatory system (47%), digestive system (36%), and nervous system (31%). Among the 45 children, 16 were administered with 400 mg/kg intravenous immunoglobulin (IVIG) daily for 5 days, with a mean duration of fever of 16±5 days, and 29 were administered with 1 g/kg IVIG daily for 2 days, with a mean duration of fever of 13±4 days; there was a significant difference in the mean duration of fever between the two groups (P=0.046). The overall mortality rate was 11%. CONCLUSIONS: Severe type 7 adenovirus pneumonia in children has severe conditions, with a high incidence rate of complications and a high mortality rate, so it should be diagnosed and treated as early as possible.

[Dynamic changes between osteopontin and collagen I expression in viral myocarditis mice].

OBJECTIVE: To study the mechanism of osteopontin (OPN) in viral myocarditis by observing the expression of OPN and collagen I (Col I) in mice myocardium. METHODS: The viral myocarditis models were achieved by infection with myocarditic coxsackievirus B3 (CVB3). The myocardium of mice was stained by HE and Masson staining, and the pathological scores and the collagen volume fraction (CVF )of myocardium were tabulated. The expression of Col I mRNA was measured by RT-PCR. The expression of OPN was detected by RT-PCR and ELISA. RESULTS: The histopathological examination revealed a prevalence of myocardial cell necrosis and obvious inflammation changes at the 7th day post-infection. Subsequently the inflammatory lesions were gradually absorbed. At the 28th day, the inflammatory cells had almost disappeared and obvious fibrosis occurred. The pathological scores and the expression of OPN mRNA were higher than those of the control group (P<0.05), and reached the highest level at the 7th day (P<0.05). From the 14th day, these parameters decreased,reflected also in the ELISA results. At the 7th day and the 14th day, the Col I expression was similar to that of control. Col I expression at the 21th and 28th days was higher than those of the control (P<0.05), and correlated positively to the CVF results. CONCLUSION: The OPN mRNA expression increased in acute stage of VMC, and higher than that of the control group when in recovery stage, suggesting that OPN might be related to the inflammatory response in acute stage of, and promote the collagen synthesis of recovery stage.

[Expression of matrix metalloproteinase-9 in myocardium of mice with viral myocarditis].

OBJECTIVE: To investigate the dynamic changes of expression of matrix metalloproteinases-9 in myocardium of mice with viral myocarditis (VMC) and its significance in the pathogenesis of viral myocarditis. METHODS: VMC model was prepared by an injection of CVB3 in BALB/C mice. The mice receiving an injection of culture solution without virus were used as the control group. Cardiac tissues were obtained 7, 14, 21 and 28 days after injection and made into paraffin sections. Myocardial histopathologic changes were observed by hematoxylin-eosin staining and Masson staining. The expression of MMP-9, type I collagen and type III collagen in cardiac tissues were quantified by SABC immunohistochemical method. RESULTS: The expression of MMP-9 in the VMC model group was observed on the 7th day, reached a peak on the 14th day, and was significantly higher than that in the control group at all time points (P<0.05). Compared with the control group, the expression of type I collagen in the VMC model group was up-regulated on the 21st day and reached a peak on the 28th day (P<0.05). The expression of type III collagen in the VMC model group was significantly higher than that in the control group on the 28th day (P<0.05). The expression of MMP-9 was positively correlated with myocardial histopathologic scores (r=0.832, P<0.05) and negatively correlated with type I collagen expression (r=-0.791, P<0.05). CONCLUSIONS: MMP-9 is over-expressed at the early stage in VMC mice, and participates in the pathological process of VMC through mediating the degradation metabolism of type I collagen. It may be an important factor that leads to myocardial collagen remodeling and myocardial fibrosis.

[Effects of mTOR inhibitor rapamycin on Smad 3 protein and collagen type I expression in rat myocardial fibroblasts infected with coxsackie virus B 3].

OBJECTIVE: Mammalian target of rapamycin (mTOR) plays a central role in controlling cell proliferation, survival and growth. We investigated the role of mTOR signal transduction on viral myocarditis by observing the effect of mTOR inhibitor rapamycin on Smad 3 and collagen type I expression in rat myocardial fibroblasts infected with coxsackievirus B 3 (CVB 3). METHODS: Primary cultured myocardial fibroblasts of SD rats infected with CVB 3 were treated with or without rapamycin. The Smad 3 and collagen type I expression of the cells were determined by RT-PCR and Western blot. RESULTS: (1) mTOR/beta-actin ratio was dose-dependently reduced (1 nmol/L, 0.381 +/- 0.022; 10 nmol/L, 0.282 +/- 0.014; 100 nmol/L, 0.263 +/- 0.012 vs. control 1.45 +/- 0.04, all P < 0.05 vs. control) after 48 hours rapamycin treatments and time-dependently reduced after 10 nmol/L rapamycin treatment (24 h, 0.203 +/- 0.021; 48 h, 0.163 +/- 0.022; 72 h, 0.144 +/- 0.013 vs. 0 h, 0.341 +/- 0.022, all P < 0.05 vs.0 h) in CVB 3 infected myocardial fibroblasts. (2) Smad 3/beta-actin ratio of myocardial fibroblasts was significantly increased in CVB 3 infected cardial fibroblasts and this increase could be significantly attenuated by rapamycin (control, 0.63 +/- 0.06; CVB 3, 1.18 +/- 0.03; CVB 3 + Rapamycin, 0.77 +/- 0.08 by RT-PCR and 0.89 +/- 0.07, 2.27 +/- 0.13 and 0.131 +/- 0.013 by Western blot). Collagen type I/beta-actin ratio was also significantly increased by CVB 3 and this increase could be reversed by rapamycin (1.13 +/- 0.06, 1.303 +/- 0.012, 0.82 +/- 0.03 by RT-PCR). CONCLUSION: Rapamycin can inhibit the Smad 3 and collagen type I expressions in CVB 3 infected myocardial fibroblasts suggesting that the mTOR signal pathway may play an important role in the pathogenesis of CVB 3 induced myocardial fibrosis.