Background: and Purpose Live cell-based assays (LCBA) are increasingly used for serological antibody detection due to their ability to preserve antigen conformation, offering moderately higher sensitivity than fixed cell-based assays. However, the clinical necessity of prioritizing LCBA for the detection of aquaporin-4 immunoglobulin G (AQP4-IgG) in neuromyelitis optica spectrum disorder (NMOSD) remains unclear, especially when compared to its established role in diagnosing myelin oligodendrocyte glycoprotein antibody-associated disease. Methods: We compared the performance of live cell-based assays using immunofluorescence (LCBA-IF) and fixed cell-based assays using immunofluorescence (FCBA-IF) in detecting AQP4-IgG in 90 cases of NMOSD meeting 2015 International Panel for Neuromyelitis Optica Diagnosis criteria, alongside 40 controls. Additionally, we further investigated the relationship between AQP4-IgG titers as measured by LCBA-IF and FCBA-IF and clinical parameters in NMOSD patients. Results: Results showed 96.9% agreement between LCBA-IF and FCBA-IF (Cohen’s κ=0.935), with a strong Spearman correlation (0.977, p<0.001). Both methods demonstrated 100% specificity, with LCBA-IF showing slightly higher sensitivity compared to FCBA-IF. Within LCBAIF-tested groups, statistically significant differences in annualized relapse rates were observed across all pairwise comparisons (low-titer vs. moderate-titer, low-titer vs. high-titer, and moderate-titer vs. high-titer; all p<0.050). However, this association reached statistical significance in some FCBA-IF-tested groups. Conclusions Overall, there is a strong concordance between LCBA-IF and FCBA-IF in detecting AQP4-IgG, where LCBA-IF shows slightly higher sensitivity. Furthermore, there is a potential link between elevated AQP4-IgG titers and an increased risk of relapse, and this correlation may appear more pronounced when using LCBA-IF.

Objective To observe the inhibitory effect of the antibodies against midgut-protein-ingredient of Anopheles stephensi on the oocysts of Plasmodium yoelii.Methods Female An.stephensi mosquitoes raised in laboratory were dissected and the midguts were collected.Eight BALB/c mice were immunized using midgut-protein(100 ?g/mouse,4 times with an interval of 7～10day).Ten days after the last immunization,blood was taken from mice armpit artery and serum separated.The immune active antigen of the midgut protein was analyzed by Western blotting.Protein with Mr 38 000～50 000 was separated by sephadex filtering and used to immunize 12 BALB/c mice(100 ?g/mouse,4 times with interval of 7～10 days).PBS control group was established.Seven days after the last immunization,serum antibody was detected by ELISA.When the antibody titer in immunized mice reached ≥1:2 560,mice in both groups were infected by P.yoelii(about 2?107 plasmodium-infected RBC) by abdominal injection.The mosquitoes were fed on the infected mice when the number of female gametes was higher than 2 per 10 microscopical fields 3 days later.After 9 days,the mosquitoes were dissected and the amount of oocysts in midgut was counted.Results Eight protein bands were shown in midgut-protein of An.stephensi by Western blotting and the band of Mr 38 000～50 000-midgut-protein appeared clearer.The infection rate of oocysts in the experiment and control groups were 28.70%(62/216) and 51.09%(47/92) respectively(P