Interleukin-5 and the posttreatment eosinophilia in patients with onchocerciasis.
To understand the role of the eosinophilopoietic cytokine IL-5 in humans, the posttreatment eosinophilic response in a group of microfilaria (mf)-positive patients with onchocerciasis (n = 10) was examined before and after treatment with diethylcarbamazine (6 mg/kg for 7 d). Sequential blood samples were assessed at 24 and 1 h before treatment (baseline values), then at frequent intervals over the next 14 d. Symptom scores, skin microfilariae (mf), and peripheral blood eosinophil counts were recorded as a function of time after treatment, and serum levels of IL-5 were quantitated by a highly sensitive (sensitivity greater than or equal to 20 pg/ml) monoclonal-based ELISA. Pretreatment eosinophil counts ranged from 240 to 1,186 eosinophils/microliter (geometric mean, 675), and the mf counts from 10 to 218 per mg skin (geometric mean, 79). After an initial decline in the peripheral eosinophil count to 28 +/- 8% of pretreatment levels at 8 h after beginning treatment, the eosinophil counts steadily increased over the next 2 wk, reaching a maximum at 14 d (257 +/- 38% of pretreatment levels). Serum levels of IL-5 rose sharply from pretreatment levels to a peak of 70.5 +/- 11 pg/ml by 24 h after treatment. Serum IL-5 remained elevated over the next 2-3 d and declined toward baseline by approximately 6 d after treatment, at which time the eosinophil levels were steadily increasing. IL-3 and granulocyte macrophage colony-stimulating factor, two other cytokines implicated in eosinophilopoeisis, were not detectable in the serum at any time before or after treatment. The rise in serum IL-5 before the posttreatment eosinophilia seen in this group of patients with onchocerciasis demonstrates a temporal relationship between IL-5 and the subsequent development of eosinophilia and implicates IL-5 as an important mediator of eosinophilia in humans.
Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892.
A P
AP
Limaye
J S
JS
Abrams
J E
JE
Silver
K
K
Awadzi
H F
HF
Francis
E A
EA
Ottesen
T B
TB
Nutman
D000293:Adolescent; D000328:Adult; D004802:Eosinophilia / Q000209:etiology*; D006801:Humans; D015848:Interleukin-5 / Q000097:blood* / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009855:Onchocerciasis / Q000097:blood* / Q000188:drug therapy
D015848:Interleukin-5