Protein D, a glycerophosphodiester phosphodiesterase, which facilitates nutrient acquisition, allowing H. influenza to thrive in nutrient scarce environments within the host was observed in strains 5P28H1/5P54H1, 6P24H2/6P32H1, 48P106H1/48P153H1, and 67P38H1/67P56H1 in this study, which belong to the chronic obstructive pulmonary disease (COPD), causing secondary immunodeficiency101. The gene discussed is DHRS2; the disease is chronic obstructive pulmonary disease.