title: Lymphocyte activation and cytokine production in autoimmune hemolytic anaemia (AIHA).
abstract: We studied 16 patients affected by autoimmune hemolytic anaemia (AIHA), both idiopathic and associated with other diseases (B and T lymphoma, B hepatitis, gastric carcinoma, systemic lupus erythematosus) or alpha-methyldopa therapy, in order to value T- and B-cell activation. We determined the count of T- and B-cell subsets in peripheral blood, the proliferative response of peripheral blood lymphocytes (PBL) to phytohemagglutinin (PHA) and to pokeweed mitogen (PWM), the percentage of CD25+ cells in culture and interleukin (IL)-1alpha, IL-2, IL-4, tumor necrosis factor (TNF)alpha and soluble IL-2 receptor (sIL-2R) levels in sera and in culture. Except for an increase in CD4+ and CD8+ T cell number in a case of AIHA associated with a T lymphoma and an increase in the percentage of CD5+ and PCA1+ B cells in two cases of AIHA associated with B lymphoma and with SLE, no further data showed a relationship with the disease possibly associated with AIHA, so both idiopathic and secondary AIHA cases were analyzed together. CD4+ T cells were reduced in number in 9 cases, while CD8+ T cells were reduced in 6 cases. The percentage of CD5+ B cells was increased in 5 cases. The percentage of PCA1+ cells was increased in all cases (mean +/- sd: 18 +/- 22 vs 0,2 +/- 1 in controls). The average PBL proliferative response to PHA was reduced (S.I. 71 +/- 55 vs 138 +/- 45 in controls) as well as that to PWM (S.I. 27 +/- 21 vs 75 +/- 24 in controls), despite IL-2 high levels, in all cases, in both sera (mean +/- sd: 648 +/- 351 pg/ml vs 16 +/- 4 pg/ml in controls) and culture supernatants (mean +/- sd: 1045 +/- 677 pg/ml vs 195 +/- 51 pg/ml in controls). In PHA stimulated cultures the percentage of CD25+ cells was reduced (mean +/- sd: 37 +/- 18 vs 63 +/- 14 in controls), sIL-2R levels were like controls in 7 cases. In sera sIL-2R levels were increased in all cases (mean +/- sd: 1256 +/- 465 U/ml vs 256 +/- 114 U/ml in controls), IL-1alpha was increased in all cases too, while IL-4 levels were increased only in 7 cases. Linear regression analysis generally showed a low relationship between S.I. and IL-2, IL-4 and sIL-2R levels in supernatants of PHA stimulated culture as well as between S.I. and the percentage of CD25+ cells. Taken together these data suggest a state of B- and T-cell hyperactivation in AIHA. The low PBL proliferative response in vitro, explained in previous studies as a temporary functional exhaustion, might be itself a sign of the complete lymphocyte activation occurring in vivo in AIHA.
authors.affiliation: Laboratory of Immunohematology, Catholic School of Medicine, Università Sacro Cuore, Rome, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Fagiolo
authors.forename: L
authors.initials: L
authors.lastname: Abenante
mesh_terms: D000328:Adult; D000368:Aged; D000744:Anemia, Hemolytic, Autoimmune / Q000209:etiology / Q000276:immunology* / Q000378:metabolism*; D001402:B-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D002478:Cells, Cultured; D002648:Child; D002675:Child, Preschool; D016207:Cytokines / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D010835:Phytohemagglutinins / Q000494:pharmacology; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism
chemical_list: D016207:Cytokines; D007376:Interleukin-2; D010835:Phytohemagglutinins; D015375:Receptors, Interleukin-2; D015847:Interleukin-4