PEDIATRICS Vol. 107 No. 3 March 2001, p. e39
ELECTRONIC ARTICLE:
Levels of Interleukin-2, Interferon-
, and Interleukin-4 in
Bronchoalveolar Lavage Fluid From Patients With
Mycoplasma Pneumonia: Implication of Tendency Toward
Increased Immunoglobulin E Production
Received Jul 5, 2000; accepted Sep 26, 2000.

From the * Department of Pediatrics and Clinical Research
Institute, Seoul National University Hospital, Seoul, Korea; and the
Department of Pediatrics, Inje University Sanggye Paik Hospital,
Seoul, Korea.
Objective. In connection with the possible relationship between Mycoplasma infection and the onset of asthma, several studies have shown not only a high level of serum total immunoglobulin E (IgE) but also the production of IgE specific to Mycoplasma or common allergens during the course of Mycoplasma infection. It has been suggested that the balance of T helper type 1 (TH1)/T helper type 2 (TH2) immune response may regulate the synthesis of IgE. The objective of this study was to investigate the pattern of cytokine response (TH1 or TH2) during an episode of acute lower respiratory tract infection caused by Mycoplasma pneumoniae.
Study Design. Using a bronchoalveolar lavage (BAL) with
flexible bronchoscopy procedure, this study determined the levels of
interleukin (IL)-2, interferon (IFN)-
(TH1), and IL-4 (TH2) in the
supernatant of BAL fluid as well as the BAL cellular profiles of
patients with Mycoplasma pneumonia
(n = 14). These results were compared with those of
patients with pneumococcal pneumonia (n = 12) or those of children with no identifiable airway infections (control group: n = 8).
Results. The BAL cellular profile in the
Mycoplasma pneumonia group was characterized by a high
percentage of neutrophils and lymphocytes. A significantly increased
level of IL-2 was found in both pneumonia groups, compared with the
control group. In contrast, the IFN-
level was not different for the
3 groups. The level of IL-4 and ratio of IL-4/IFN-
were
significantly elevated in the Mycoplasma pneumonia
group, but not in the pneumococcal pneumonia group, compared with the
controls.
Conclusions. IL-4 levels and IL-4/IFN-
ratios in BAL
fluid are significantly higher in patients with
Mycoplasma pneumonia than in patients with pneumococcal
pneumonia or control participants. The BAL cytokine data suggest a
predominant TH2-like cytokine response in Mycoplasma pneumonia, thus representing a favorable condition for IgE
production.
Key words:
interleukin-2,
interferon-
,
interleukin-4,
bronchoalveolar lavage,
Mycoplasma,
pneumococcus,
pneumonia.




