RNA-sequencing-based detection of human viral pathogens in cerebrospinal fluid and serum samples from children with meningitis and encephalitis.

Encephalitis and meningitis are notable global public health concerns, especially among infants or children. Metagenomic next-generation sequencing (mNGS) has greatly advanced our understanding of the viruses responsible for these diseases. However, the detection rate of the aetiology remains low. We conducted RNA sequencing and virome analysis on cerebrospinal fluid (CSF) and serum samples commonly used in the clinical diagnosis to detect viral pathogens. In total, 226 paired CSF and serum samples from 113 children with encephalitis and meningitis were enrolled. The results showed that the diversity of viruses was higher in CSF, with a total of 12 viral taxa detected, including one case each of herpesvirus, coronavirus and enterovirus, and six cases of adenovirus related to human diseases. In contrast, the Anelloviridae was the most abundant viral family detected in serum, and only a few samples contained human viral pathogens, including one case of enterovirus and two cases of adenovirus. The detection rate for human viral pathogens increases to 10.6 %(12/113) when both types of samples are used simultaneously, compared to CSF along 7.9 % (9/113) or serum alone 2.6 % (3/113). However, we did not detect these viruses simultaneously in paired samples from the same case. These results suggest that CSF samples still have irreplaceable advantages for using mNGS to detect viruses in patients with meningitis and encephalitis, and serum can supplement to improve the detection rate of viral encephalitis and meningitis. The findings of this study could help improve the etiological diagnosis, clinical management and prognosis of patients with meningitis and encephalitis in children.

Characteristics and serological patterns of COVID-19 convalescent plasma donors: optimal donors and timing of donation.

BACKGROUND: The lack of effective treatments against the 2019 coronavirus disease (COVID-19) has led to the exploratory use of convalescent plasma for treating COVID-19. Case reports and case series have shown encouraging results. This study investigated SARS-CoV-2 antibodies and epidemiological characteristics in convalescent plasma donors, to identify criteria for donor selection. METHODS: Recovered COVID-19 patients, aged 18-55 years, who had experienced no symptoms for more than 2 weeks, were recruited. Donor characteristics such as disease presentations were collected and SARS-CoV-2 N-specific IgM, IgG, and S-RBD-specific IgG levels were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: Whereas levels of N-specific IgM antibody declined after recovery, S-RBD-specific and N-specific IgG antibodies increased after 4 weeks from the onset of symptoms, with no significant correlation to age, sex, or ABO blood type. Donors with the disease presentation of fever exceeding 38.5°C or lasting longer than 3 days exhibited higher levels of S-RBD-specific IgG antibodies at the time of donation. Of the 49 convalescent plasma donors, 90% had an S-RBD-specific IgG titer of ≥1:160 and 78% had a titer of ≥1:640 at the time of plasma donation. Of the 30 convalescent plasma donors, who had donated plasma later than 28 days after the onset of symptoms and had a disease presentation of fever lasting longer than 3 days or a body temperature exceeding 38.5°C, 100% had an S-RBD-specific IgG titer of ≥1:160 and 93% had a titer of ≥1:640. CONCLUSION: This study indicates that the S-RBD-specific IgG antibody reaches higher levels after 4 weeks from the onset of COVID-19 symptoms. We recommend the following selection criteria for optimal donation of COVID-19 convalescent plasma: 28 days after the onset of symptoms and with a disease presentation of fever lasting longer than 3 days or a body temperature exceeding 38.5°C. Selection based on these criteria can ensure a high likelihood of achieving sufficiently high S-RBD-specific IgG titers.

A genetic polymorphism of IL17F rs763780 associated with anti-E production in the Han Chinese population.

OBJECTIVE: This study aimed to investigate the association among 4 single nucleotide polymorphisms (SNPs) in the genes TLR3, IL17F, ERAP1 and ERAP2 with anti-E alloantibody production. BACKGROUND: Anti-E alloantibodies can lead to clinically significant delayed hemolytic transfusion reactions (DHTRs) and hemolytic disease of the newborn (HDN). Some individuals produce anti-E alloantibodies post- transfusion. The mechanisms controlling this process is poorly understood. METHODS: Ninety-five patients with anti-E alloantibodies were enrolled, and samples from 186 healthy donors were used as controls. Four SNPs in the immune-related genes (TLR3, IL17F, ERAP1 and ERAP2) were selected. SNPs were analyzed by polymerase chain reactions (PCR) and TaqMan assays. Allele and genotype frequencies were compared using Pearson's chi-square test. RESULTS: The C allele and CC + CT genotypes of rs763780 in the IL17F gene were overrepresented in the E- alloimmunized patient group (14.2 % vs. 5.1 %, P < 0.001; 23.2 % vs. 9.7 %; P = 0.004). Individuals with CC + CT genotypes of rs763780 had a higher risk of E-alloimmunization. (OR, 2.81; 95 % CI, 1.42-5.56). No significant difference was observed among the other 3 SNPs. CONCLUSIONS: SNP rs763780 in the IL17F gene was associated with E-alloimmunization in a sample of the Han Chinese population, with the allele C as a risk allele.