Chest
Volume 113, Issue 3, March 1998, Pages 788-794
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Laboratory and Animal Investigations
Elevated Pleural Fluid Levels of Defensins in Patients With Empyema

https://doi.org/10.1378/chest.113.3.788Get rights and content

Background

Defensins, also known as human neutrophil peptides, are antimicrobial peptides present in the azurophil granules of neutrophils. We measured their level in pleural effusion in various pulmonary diseases to investigate whether they could be used as a diagnostic marker in the differential diagnosis of specific pleural diseases.

Patients and participants

We analyzed pleural effusion samples collected from 61 patients, including 50 exudates (11 with empyema, 3 parapneumonic, 15 tuberculous, 18 neoplastic, 3 miscellaneous) and 11 transudates as controls.

Measurements

Defensins were measured by radioimmunoassay and also analyzed by reverse-phase high-performance liquid chromatography. The concentrations of interleukin (IL)-8 and granulocyte colony-stimulating factor (G-CSF) in pleural effusion fluid were measured by enzyme-linked immunosorbent assay to examine the correlation between these cytokines and defensins.

Results

The concentration of defensins in all samples of empyema was >5,100 ng/mL and the mean concentration (13,265.8±1, 895.2 ng/mL) in these samples was the highest among other groups. The concentration in the other 50 pleural effusion samples tested was <2, 800 ng/mL. Defensins were mostly of the mature type in empyema. Pleural effusion levels of IL-8 and G-CSF in patients with empyema were also significantly higher than those in other samples. There was a significant correlation between defensins and IL-8 or G-CSF in pleural effusion fluid (r=0.762, and 0.827, respectively).

Conclusions

Our results suggest that the high effusion concentrations of defensins in pleural effusion may constitute an important component of the host defense system or may have a cytotoxic role in empyema. Our results also indicate that the high levels of IL-8 and G-CSF in empyema may indirectly explain the elevated levels of defensins by increasing the number of neutrophils in the pleural space.

Section snippets

Patients and Diagnostic Categories

We studied 61 consecutive patients with pleural effusions who were admitted to our hospital between September 1991 and July 1996. They consisted of 16 women and 45 men, aged 64.0±5.3 years. Thoracentesis was performed in each patient and pleural fluid samples obtained were centrifuged at 500×g for 10 min and supernatants were stored at —20°C until analysis. Pleural effusions were categorized as transudates (ratio of pleural fluid to serum total protein concentration <0.5 and ratio of those of

Results

All pleural fluid samples analyzed in the present study contained defensins. Although the concentration of defensins varied from one type of effusion to another, it was significantly higher in empyema (13,265.8±1,895.2 ng/mL) than in other groups. Furthermore, the concentration of defensins was >5, 100 ng/mL in all the samples of empyema, which was true for none of the other 50 effusion samples tested (Fig 1, top [A]). The concentration of defensins in each exudative effusion of other groups

Discussion

The major findings of the present study were the presence of high concentrations of defensins in pleural effusion of patients with empyema. Because the localization of defensins is restricted to cells of neutrophil lineage,1, 2, 13 such high levels must be due to neutrophil accumulation in the pleural space in these patients. Furthermore, the level of defensins in pleural effusion was >5, 100 ng/mL in patients with empyema but not in any of the other patients. This finding suggests that these

References (27)

  • SegalGP et al.

    In vitro effect of phagocyte cationic peptides on Coccidioides immitis

    J Infect Dis

    (1985)
  • LehrerRI et al.

    Direct inactivation of viruses by MCP-1 and MCP-2, natural peptide antibiotics from rabbit leukocytes

    J Virol

    (1985)
  • DaherKA et al.

    Direct inactivation of viruses by human granulocyte defensins

    J Virol

    (1986)
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