Volume 21, Number 12—December 2015
Dispatch
Kinetics of Serologic Responses to MERS Coronavirus Infection in Humans, South Korea
Table 2
Clinical factors | Difference in rates of change in log antibody titers |
||||
---|---|---|---|---|---|
PRNT50 titer | p value | S1-ELISA OD ratio | p value | ||
Severe disease | 0.09 | 0.01 | 0.08 | 0.07 | |
Male sex† | 0.07 | 0.05 | 0.14 | 0.01 | |
Age >60 y† | 0.05 | 0.22 | −0.03 | 0.65 | |
Incubation period, d† | 0.01 | 0.16 | 0.02 | 0.004 | |
Use of corticosteroid† | 0.06 | 0.37 | −0.04 | 0.58 | |
Use of antiviral drugs† | 0.06 | 0.10 | 0.05 | 0.35 | |
Concomitant conditions† | 0.06 | 0.06 | 0.07 | 0.16 |
*Differences in rates of change and p values were estimated by using linear mixed models; positive value indicates a faster increase in antibody titer. Given that the antibody titers exhibited an S-shaped pattern, the analysis was restricted to data for log-phase antibody responses by manually removing data from the inductive/steady-state phase. Increases in antibody titers during the log phase were compared by different factors, adjusted for disease severity, by using a linear mixed model to account for repeated measurements, assuming a linear increasing trend by days since illness onset. PRNT50 titers were first log-transformed (with base 10). OD, optical density; PRNT50, 50% endpoint plaque reduction neutralization test.
†Effects were adjusted for severity.
1These authors contributed equally to this article.