Pneumocystis: A Novel Pathogen in Chronic Obstructive Pulmonary Disease?

Figures & data

Table 1 Evidence linking Pneumocystis colonization and COPD

Increased Pneumocystis colonization in COPD patients compared to other lung diseases

Accelerated emphysema in HIV-infected subjects

Increased Pneumocystis colonization in HIV-infected smokers

Development of permanent COPD-like change after PCP

Similarity of inflammatory response in Pneumocystis colonization and COPD

Development of airway obstruction and emphysema in primate model of Pneumocystis colonization

Abbreviations: COPD, chronic obstructive pulmonary disease, PHP, Pneumocystis, pneumonia.

Table 2 Summary of studies reporting prevalence of Pneumocystis colonization in COPD

Study	n	Population	Technique/sample	% colonized
Calderon, 1996	50	Patients with chronic bronchial disease	IHC stains, IF stains/sputum	10.0%
Sing, 1999	8	Patients with COPD	Nested PCR/BAL	37.5%
Probst, 2000	37	Patients with COPD	Nested PCR/BAL and sputum	40.5%
Helweg-Larsen, 2002	23	In-patients with suspected bacterial pneumonia and COPD	Touch-down PCR/BAL, sputum, and tracheal aspirates	43.5%
Maskell, 2003	23	Patients with COPD undergoing bronchoscopy	Nested PCR/BAL	17.4%
Calderon, 2004	37	Patients with chronic bronchitis	Nested PCR/sputum	40.5%
Morris, 2004	68	Smokers undergoing lung surgery	Nested PCR/lung tissue	36.7% of GOLD IV
				5.3% of GOLD 0-III

Abbreviations: BAL, bronchoalveolar lavage; COPD, chronic obstructive pulmonary disease; GOLD, Global Initiative on Obstructive Lung Disease; IF, immunofluorescence; IHC, immunohistochemical; PCR, polymerase chain reaction.

Figure 1 Comparison of FEV₁ and FEV₁/FVC in Pneumocystis-colonized subjects and Pneumocystis negative. p = 0.006 for both comparisons. Abbreviations: FVC, forced vital capacity; FEV₁, forced expiratory volume in 1 second, percent predicted.

Figure 2 Association of GOLD stage and prevalence of Pneumocystis colonization. Reproduced with permission from American Journal of Respiratory and Critical Care Medicine. Abbreviations: GOLD, Global Health Initiative on Obstructive Lung Disease.

Figure 3 Change in forced expiratory volumes and forced expiratory flow values for non-colonized monkeys from baseline (uninfected) to follow-up (SHIV-infected, Pneumocystis-negative) and for Pneumocystis-colonized monkeys from baseline (uninfected) to follow-up (SHIV-infected, Pneumocystis-colonized). Average follow-up of 8 months. * p = 0.02 for comparison of change in FEV_0.4 and FEF_{25 − 75} in non-colonized versus Pneumocystis-colonized. Abbreviations: FEV_0.4, forced expiratory volume during first 0.4 seconds; FEF_{25 − 75}, forced expiratory flow over mid 50% of forced vital capacity; Pc, Pneumocystis.