Inflammatory responses in blood samples of human immunodeficiency virus-infected patients with pulmonary infections

Abstract

We analyzed the characteristics of the inflammatory response occurring in blood during pulmonary infections in human immunodeficiency virus (HIV)-infected patients. A prospective study of consecutive hospital admissions of HIV-infected patients with new-onset radiologic pulmonary infiltrates was carried out in a tertiary university hospital from April 1998 to May 2001. Plasma cyclic AMP receptor protein (CRP), interleukin 1beta (IL-1beta), IL-6, IL-8, IL-10, and tumor necrosis factor alpha (TNF-alpha) levels were determined at the time of admission and 4, 5, and 6 days later. Patients were included in a protocol addressed to study etiology and outcome of disease. A total of 249 episodes of infection were included, with the main diagnoses being bacterial pneumonia (BP) (118 episodes), Pneumocystis carinii pneumonia (PCP) (41 episodes), and mycobacteriosis (36 episodes). For these three patient groups, at the time of admission the median CRP and cytokine levels were as follows: CRP, 10.2, 3.8 and 5 mg/dl, respectively (P = 0.0001); IL-8, 19, 3, and 2.9 pg/ml (P = 0.045); and TNF-alpha, 46.4, 44, and 75 pg/ml, respectively (P = 0.029). There were no significant differences in levels of IL-1beta, IL-6, or IL-10 among the patient groups. A total of 23 patients died. At the time of admission, HIV-infected patients with BP had higher plasma CRP and IL-8 levels than did PCP and mycobacteriosis patients. TNF-alpha levels were higher in patients with mycobacteriosis. An elevated IL-8 level (>61 pg/ml) at the time of admission was an independent factor associated with higher mortality (odds ratio, 12; 95% confidence interval, 1.2 to 235.5).

FIG. 1.

Distribution of plasma CRP, IL-8, and IL-10 levels at admission in the main diagnostic groups (BP, PCP, and mycobacteriosis) in patients classified according to a CD4 lymphocyte count higher or lower than 200/mm³. In the basic box-and-whisker plot, the central box represents the values from the 25th to the 75th percentile and therefore contains the middle half of the scores in the distribution. The numerical difference between the third quartile (75th percentile) and first quartile (25th percentile) is the interquartile range, a measure of the spread of the data. The middle line represents the median. Lines extend from the central box to the minimum and the maximum values, excluding outlier values, which are displayed as separate points: an outside value is defined as a value that is smaller than the first quartile minus 1.5 times the interquartile range or larger than the third quartile plus 1.5 times the interquartile range (inner fences). These values are plotted with a round marker. A far-out value is defined as a value that is smaller than the first quartile minus three times the interquartile range or larger than the third quartile plus three times the interquartile range (outer fences).