Figure 2.

CBF response to sildenafil: (A) Absolute CBF on day 0 for patients with PNTM disease prior and 2 hours post a single dose of either 20 mg sildenafil (n=3) or 40 mg sildenafil (n=5). Patients with PNTM disease had a mean CBF of 8.96±1.2 Hz, with no significant difference between the two groups prior to sildenafil dose. The 40 mg sildenafil group’s CBF was significantly elevated to 10.79±0.6 Hz (p<0.008, two-tailed t-test) post sildenafil. (B) Mean absolute CBF at days 0, 7 and 30 (n=9). CBF measurement was done at prior to sildenafil at day 0. CBF was measured prior to and post the 20 mg dose of sildenafil at the end of 1 week (day 7 pre-time and post-time point) and prior to and post the 40 mg dose of sildenafil at 4 weeks (day 30 pre-time and post-time point). CBF at the day 30 post sildenafil dose was significantly elevated to 10.73±1.2 Hz compared with day 0 predose (p<0.004, ANOVA with Dunnett correction). CBF for historical healthy controls¹¹ represented by greyed zone on the y-axis (data are presented as means, error bars show SD, **p<0.01). ANOVA, analysis of variance; CBF, ciliary beat frequency; PNTM, pulmonary non-tuberculous mycobacteria.