Immune Function in Patients with Invasive Pneumococcal Disease

Abstract

Background: Invasive pneumococcal disease (IPL) is a serious condition caused by the bacteria Streptococcus pneumoniae. It is most common in children and elderly. People with chronic diseases and immunodeficiency are especially vulnerable to IPD. Aim: To determine whether IPD patients differed in immune function compared to healthy controls. Method: Immunoglobulin (Ig) levels and IgG subclass levels were measured in 60 patients during the acute phase of the infection, and an extensive immune function analysis was performed in 18 healthy controls and 16 IPD patients 2 —4 months after recovery in the convalescent phase. The immune results from the acute phase and convalescent phase were compared, as were the results between the patients and the controls. Clinical data was collected from the patient's journals. Results: The patients had significantly higher IgM levels in the convalescent phase than the controls, and the IgG2 and IgG4 levels were significantly lower in the patients in the acute phase than in the controls. The patients also had significantly Iower levels of total lymphocytes, total T cells, helper T cells, and B cells in the convalescence phase, compared to the control, and the patient's monocyte function was also significantly lower than the controls'. NO difference in B cell function could be seen, and no correlation could be found between the immune tests and the severity of the patients' illness. Conclusions: This study suggests that several of the immune functions of IPD patients differ from that of healthy controls. Although several results coincided with those obtained by other studies, several results were also inconsistent with other studies. This indicates that the knowledge on the subject remains incomplete, and further research is necessary.