MAOB and asthma: However, no significant differences were found between non-severe (0.85 nmol/mg of protein, 0.64–1.10) and severe (0.75 nmol/mg of protein, 0.62–1.04) asthma patients in platelet 5-HT concentration (p = 0.38, Mann-Whitney test), or between non-severe (44.22 nmol/mg of protein/h, 34.65–56.74) and severe asthma patients (43.00 nmol/mg of protein/h, 33.84–82.15) in platelet MAO-B activity (p = 0.80, Mann-Whitney test) (Figure 2).