Figure 3: Peripheral lymphocyte count and CD4 T cell count in respiratory diseases. Peripheral lymphocyte count and CD4 T cell count in idiopathic pulmonary fibrosis (IPF), collagen vascular-related IP (CVD), chronic bronchitis (CB)/pneumonia (pneumo) and pneumocystis pneumonia (PCP) groups. Peripheral lymphocyte count and CD4 T cell count in IP patients on oral corticosteroid therapy with P. jirovecii colonization versus those without colonization.

Mentions: Serum levels of KL-6 were higher in the IPF (1278.5 ± 740.4) and PCP (1488 ± 1086.1) groups than in the CB/Pneumonia group (375.8 ± 300.8). The KL-6 level of the CVD group (898.2 ± 605.3) was not different from that of the PCP group (Fig. 2a). SP-A levels did not show significant differences among the IPF group (88.7 ± 36.2), CVD group (73.2 ± 52.1), CB/Pneumonia group (73.3 ± 41.4), and PCP group (121.9 ± 24.7) (Fig. 2b). SP-D levels also did not show significant differences among the IPF group (166.9 ± 111.1), CVD group (92.7 ± 67.7), CB/Pneumonia group (131 ± 71.0), and PCP group (194.1 ± 157.5) (Fig. 2c). The β-D-glucan level of the PCP (32.8 ± 35.1) was significantly higher than that of the other groups (the IPF, CVD, and CB/pneumonia groups all had levels under the detection limit of <3.4) (Fig. 2d). Levels of serum markers did not show any significant differences between IP patients with and without P. jirovecii colonization on oral corticosteroid therapy with respect to KL-6 (1370 ± 810.4 vs. 1030.6 ± 594.6), SP-A (86.6 ± 32.8 vs. 73.5 ± 44.5), SP-D (142.8 ± 145.1 vs. 102.3 ± 121.9), and β-D-glucan (both groups were under the detection limit) (Figs. 2e, f, g and 2h). The lymphocyte count of the PCP group (397.1 ± 151.6) was significantly lower than those of the other groups (IPF: 1480.2 ± 917.1; CVD: 1543.8 ± 919.6; and CB/pneumonia: 1118.4 ± 445.3). CD4 T cell counts showed no statistical differences among the four groups (IPF: 614.8 ± 469; CVD: 711.8 ± 431.1; CB/pneumonia: 403.3 ± 369.9; and PCP: 129 ± 96.7) (Figs. 3a, b). The lymphocyte count and CD4 T cell count showed no statistical differences between IP patients with and without P. jirovecii colonization on oral corticosteroids (Figs. 3c, d). The peripheral lymphocyte count of the former group was 1206.7 ± 859.7 and that of the latter group was 1144.6 ± 560.0, while the CD4 T cell count was 651.6 ± 565.6 and 401.5 ± 235.4, respectively.

Shimizu Y, Sunaga N, Dobashi K, Fueki M, Fueki N, Makino S, Mori M - BMC Infect. Dis. (2009)

Bottom Line: In IP patients, oral corticosteroid therapy was a significant risk factor for P. jirovecii colonization (P < 0.05).Serum markers did not show differences between IP patients with and without P. jirovecii colonization.However, the serum beta-D-glucan level and lymphocyte count were useful for distinguishing P. jirovecii colonization from pneumocystis pneumonia in IP patients.

Affiliation: Department of Medicine and Molecular Science, Gunma University Graduate School of Medicine, Showa-machi, Maebashi Gunma, Japan. yasuos@med.gunma-u.ac.jp

Abstract: In patients with chronic respiratory disease, Pneumocystis jirovecii (P. jirovecii) colonization is observed, and may influence disease progression and systemic inflammation. Pneumocystis pneumonia causes interstitial changes, so making a diagnosis of PCP in patients who have interstitial pneumonia (IP) with P. jirovecii colonization is sometimes difficult based on radiography.This study investigated the prevalence of P. jirovecii colonization in IP patients and assessed pulmonary injury due to P. jirovecii colonization by measurement of serum markers (KL-6, SP-A, SP-D, and (1-->3) beta-D-glucan (beta-D-glucan)) and the peripheral lymphocyte counts, prospectively. A total of 75 patients with idiopathic pulmonary fibrosis (n = 29), collagen vascular-related interstitial pneumonia (n = 19), chronic bronchitis or pneumonia (n = 20), and Pneumocystis pneumonia (n = 7) were enrolled in this prospective study. P. jirovecii DNA was detected in sputum samples, while serum markers and the lymphocyte count were measured in the peripheral blood.IP patients (idiopathic pulmonary fibrosis and collagen vascular-related IP) who received oral corticosteroids had a high prevalence of P. jirovecii colonization (23.3%). In IP patients, oral corticosteroid therapy was a significant risk factor for P. jirovecii colonization (P < 0.05). Serum markers did not show differences between IP patients with and without P. jirovecii colonization. The beta-D-glucan level and lymphocyte count differed between patients with Pneumocystis pneumonia or P. jirovecii colonization.Serum levels of KL-6, SP-A, SP-D, and beta-D-glucan were not useful for detecting P. jirovecii colonization in IP patients. However, the serum beta-D-glucan level and lymphocyte count were useful for distinguishing P. jirovecii colonization from pneumocystis pneumonia in IP patients.