A case of hypereosinophilic syndrome is associated with the expansion of a CD3-CD4+ T-cell population able to secrete large amounts of interleukin-5.
Interleukin-5 (IL-5) is the major soluble factor able to mediate hypereosinophilia. We report a case of hypereosinophilic syndrome in which the presence of a population of CD3-CD4+ cells able to overproduce IL-5 was shown. The lack of CD3 and TCRAB membrane expression on otherwise phenotypically normal mature T lymphocytes together with the absence of detectable TCRBV mRNA and clonal rearrangement of TCRB gene suggested that the abnormal lymphocyte population was the expression of a peripheral T-cell lymphoma with an indolent clinical course. Peripheral blood lymphocytes enriched in this population were able to secrete high levels of IL-5 but not IL-4, and no IL-2 or interferon-gamma, when stimulated in vitro with phytohemagglutinin and phorbol myristate acetate. The serum contained eosinophil survival factors whose activity was partially neutralized by a specific antihuman IL-5 antibody. This observation further emphasized the relationship between hypereosinophilic syndrome. IL-5, and T-cell lymphoproliferative disorders.
Brugnoni
D
D
Servizio di Immunologia Clinica, CONBIOTEC, III, Spedali Civili di Brescia, Italy.
Airó
P
P
Rossi
G
G
Bettinardi
A
A
Simon
H U
HU
Garza
L
L
Tosoni
C
C
Cattaneo
R
R
Blaser
K
K
Tucci
A
A
D000368:Aged; D001483:Base Sequence; D015496:CD4-Positive T-Lymphocytes / Q000502:physiology*; D002470:Cell Survival; D017931:DNA Primers / Q000737:chemistry; D004804:Eosinophils / Q000166:cytology; D015329:Gene Rearrangement, T-Lymphocyte; D005796:Genes; D006801:Humans; D017681:Hypereosinophilic Syndrome / Q000209:etiology*; D015848:Interleukin-5 / Q000378:metabolism*; D008213:Lymphocyte Activation; D008297:Male; D008969:Molecular Sequence Data; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics
D017931:DNA Primers; D015848:Interleukin-5; D016693:Receptors, Antigen, T-Cell, alpha-beta