ABSTRACT
【Objective】 To explore the molecular hereditary and frequency of Jk(a-b-) in blood donors in Yichang. 【Methods】 A total of 49 999 samples from Yichang Red Cross Central Blood Station were screened for Jk(a-b-) by urea hemolysis test(2 mol /L). The phenotypes of JK (a-b -) probands and their families were confirmed by monoclonal anti-Jka and anti-Jkb, and the whole exon of SLC14A1 gene was sequenced. 【Results】 The frequency of Jk(a-b-) in Yichang blood donors was 0.004% (2/49 999), and the exon sequencing of SLC14A1 gene confirmed that both two probands were JK*02N.01 caused by c. 342-1G>A homozygous mutation.Besides, JK*01W.01 allele was observed in the pedigree analysis, and weak expression of Jka was found in 4 out of 11 family members. 【Conclusion】 The frequency of JK (a-b -) in Yichang blood donors is similar to those in Shanghai 0.004%(2/48 400), and both caused by JK * 02N.01 allele with high frequency in Southeast Asia. The epidemiological survey of JK * 01w.01 allele frequency should be further performed.
ABSTRACT
Prolonged viral shedding is associated with severe status and poor prognosis of COVID-19 patients. Unexpectedly, here we report a non-severe patient with the longest duration of viral shedding. According to the investigation on the clinical and epidemiological information of this case, we concluded that this type of virus might have a low toxicity and transmissibility, but have a prolonged infective ability and was hardly to be eliminated in the body with regular therapy. However, infusion of plasma from recovered patients showed high efficiency in elimination of this virus. Our findings might shed light on the management of COVID-19.
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BackgroundAt present, PCR-based nucleic acid detection cannot meet the demands for coronavirus infectious disease (COVID-19) diagnosis. Methods214 confirmed COVID-19 patients who were hospitalized in the General Hospital of Central Theater Command of the Peoples Liberation Army between January 18 and February 26, 2020, were recruited. Two Enzyme-Linked Immunosorbent Assay (ELISA) kits based on recombinant SARS-CoV-2 nucleocapsid protein (rN) and spike protein (rS) were used for detecting IgM and IgG antibodies, and their diagnostic feasibility was evaluated. ResultsAmong the 214 patients, 146 (68.2%) and 150 (70.1%) were successfully diagnosed with the rN-based IgM and IgG ELISAs, respectively; 165 (77.1%) and 159 (74.3%) were successfully diagnosed with the rS-based IgM and IgG ELISAs, respectively. The positive rates of the rN-based and rS-based ELISAs for antibody (IgM and/or IgG) detection were 80.4% and 82.2%, respectively. The sensitivity of the rS-based ELISA for IgM detection was significantly higher than that of the rN-based ELISA. We observed an increase in the positive rate for IgM and IgG with an increasing number of days post-disease onset (d.p.o.), but the positive rate of IgM dropped after 35 d.p.o. The positive rate of rN-based and rS-based IgM and IgG ELISAs was less than 60% during the early stage of the illness 0-10 d.p.o., and that of IgM and IgG was obviously increased after 10 d.p.o. ConclusionsELISA has a high sensitivity, especially for the detection of serum samples from patients after 10 d.p.o, it can be an important supplementary method for COVID-19 diagnosis.
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BackgroundThe colloidal gold immunochromatography assay (GICA) is a rapid diagnostic tool for novel coronavirus disease 2019 (COVID-19) infections. However, with significant numbers of false negatives, improvements to GICA are needed. MethodsSix recombinant HCoV-19 nucleocapsid and spike proteins were prepared and evaluated. The optimal proteins were employed to develop a sandwich-format GICA strip to detect total antibodies (IgM and IgG) against HCoV-19. GICAs performance was assessed with comparison of viral RNA detection. ResultsRecombinant HCoV-19 proteins were obtained, including three prokaryotically expressed rN, rN1, rN2 nucleocapsid proteins, and three eukaryotically expressed rS1, rS-RBD, rS-RBD-mFc spike proteins. The recombinant proteins with the highest ELISA titers (rS1 and rS-RBD-mFc) against coronavirus-specific IgM and IgG were chosen for GICA development. The GICA has a sensitivity and specificity of 86.89% (106/122) and 99.39% (656/660), respectively. Furthermore, 65.63% (21/32) of the clinically confirmed but RT-PCR negative samples were GICA positive. ConclusionsThe eukaryotically-expressed spike proteins (rS1and rS-RBD-mFc) are more suitable than the prokaryotically expressed nucleocapsid proteins for HCoV-19 serological diagnosis. The GICA sandwich used to detect total antibodies is a powerful complement to the current standard RNA-based tests.
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BackgroundThe outbreak of the recently emerged novel corona virus disease 2019 (COVID-19) poses a challenge for public health laboratories. We aimed to evaluate the diagnostic value of serological assay for SARS-CoV-2. MethodsA newly-developed ELISA assay for IgM and IgG antibodies against N protein of SARS-CoV-2 were used to screen the serums of 238 admitted hospital patients with confirmed or suspected SARS-CoV-2 infection from February 6 to February 14, 2020. SARS-CoV-2 RNA was detected by real time RT-PCR on pharyngeal swab specimens. FindingsOf the 238 patients, 194 (81.5%) were detected to be antibody (IgM and/or IgG) positive, which was significantly higher than the positive rate of viral RNA (64.3%). There was no difference in the positive rate of antibody between the confirmed patients (83.0%, 127/153) and the suspected patients (78.8%, 67/85) whose nucleic acid tests were negative. After the patients were defined to the different stages of disease based on the day when the test samples were collected, the analysis results showed that the antibody positive rates were very low in the first five days after initial onset of symptoms, and then rapidly increased as the disease progressed. After 10 days, the antibody positive rates jumped to above 80% from less than 50%. On the contrary, the positive rates of viral RNA kept above 60% in the first 11 days after initial onset of symptoms, and then rapidly decreased. In addition, half of the suspected patients with symptoms for 6-10 days were detected to be antibody positive. InterpretationThe suspected patients were most likely infected by SARS-CoV-2. Before the 11th day after initial onset of symptoms, nucleic acid test is important for confirmation of viral infection. The combination of serological assay can greatly improve the diagnostic efficacy. After that, the diagnosis for viral infection should be majorly dependent on serological assay.
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Objective: To study the role of auto-antibody in the diagnosis of patients with PBC. Methods: ANA, SMA and AMA in serum of 58 PBC patients were tested by indirect immune fluorescence and Western blot. Such auto-antibodies as Anti-type AMAM2,anti-SLA/LP, anti-LKM-1 and anti-LC-1 were also identified. Results: Auto-antibodies existing in patients with PBC were mainly AMA(96.5%) and AMAM2(93.1%) and the titer was beyond 1∶100. 8 cases of those patients were positive with ANA and SMA simultaneously. One case had positive AMA and SLA/LP in serum and the clinical appearances were the same as those of type Ⅰ and type Ⅲ autoimmune hepatitis. 19 patients with positive AMAM2 in serum had liver-puncture and the results suggested the diagnosis of PBC in 63.7%(12/9). Conclusion: Test of auto-antibodies is clinically significant for the diagnosis of autoimmune hepatitis.
