CD207+/CD1A+ CIRCULATING CELLS ARE PRESENT IN PATIENTS WITH ACTIVE LANGERHANS CELL HISTIOCYTOSIS

ROSSO DIEGO A.; TESSONE LICINA; ESTECHO IVANA G.; ELENA GRACIELA; ARMESTO ARNALDO R.; CARRERA SILVA EUGENIO A.; ERRASTI ANDREA E.

Dublin

Congreso; 32nd Annual Meeting of the Histiocyte Society; 2016

Histiocyte Society

<!-- /* Font Definitions */@font-face{font-family:宋体;mso-font-charset:80;mso-generic-font-family:auto;mso-font-pitch:variable;mso-font-signature:3 680460288 22 0 262145 0;}@font-face{font-family:"Cambria Math";panose-1:2 4 5 3 5 4 6 3 2 4;mso-font-charset:0;mso-generic-font-family:auto;mso-font-pitch:variable;mso-font-signature:-536870145 1107305727 0 0 415 0;}@font-face{font-family:Calibri;panose-1:2 15 5 2 2 2 4 3 2 4;mso-font-charset:0;mso-generic-font-family:auto;mso-font-pitch:variable;mso-font-signature:-520092929 1073786111 9 0 415 0;} /* Style Definitions */p.MsoNormal, li.MsoNormal, div.MsoNormal{mso-style-unhide:no;mso-style-qformat:yes;mso-style-parent:"";margin-top:0in;margin-right:0in;margin-bottom:10.0pt;margin-left:0in;mso-pagination:widow-orphan;font-size:11.0pt;font-family:Calibri;mso-ascii-font-family:Calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:Calibri;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"Times New Roman";mso-bidi-theme-font:minor-bidi;mso-ansi-language:ES;mso-fareast-language:ZH-CN;}.MsoChpDefault{mso-style-type:export-only;mso-default-props:yes;font-size:11.0pt;mso-ansi-font-size:11.0pt;mso-bidi-font-size:11.0pt;font-family:Calibri;mso-ascii-font-family:Calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:Calibri;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"Times New Roman";mso-bidi-theme-font:minor-bidi;mso-ansi-language:ES;mso-fareast-language:ZH-CN;}.MsoPapDefault{mso-style-type:export-only;margin-bottom:10.0pt;}@page WordSection1{size:8.5in 11.0in;margin:1.0in 1.25in 1.0in 1.25in;mso-header-margin:.5in;mso-footer-margin:.5in;mso-paper-source:0;}div.WordSection1{page:WordSection1;}-->Background/Purpose:  LangerhansCells Histiocytosis (LCH) is a disorder characterized by an abnormalaccumulation of CD207+CD1a+ myeloid cells in almost anytissue. It was recently identified that monocytes as well as CD1c+dendritic cells can achieve high levels of langerin (CD207), CD1a and Birbeckgranules when exposed to TGF-b and TSLP. However the precursors of these pathogenic LC cells were not yet clearlydefined in vivo. Here, we want to evaluate the hypothesis that circulatingprecursor cells expressing CD207 and/or CD1a should be present in activemultisystem and/or multifocal LCH patients.Methods: Pediatric patients with confirmed diagnosis of LCH were stratified asunisystem, multisystem, unifocal, mutifocal with active disease (AD) or non-activedisease (NAD).  The expression of CD1aand CD207 was analyzed in the myeloid compartment of peripheral bloodmononuclear cells of LCH children and compared with same compartment of cellsfrom healthy adults and umbilical cord blood by FACS analysis.  Results: The myeloid compartment showed a significant increase (p< 0.01) ofCD11b fraction including CD11bhigh plus CD11b+ (36.39 ±3.68, N=11) in AD patients compared to NAD patients (18.87 ± 1.73, N=12) andhealthy adults (24.87 ± 1.30, N=12). We have also identified the presence ofhigh percentage of circulating CD11bhighCD11c+CD207+cells (39.01 ± 9.36, N=12) in AD patients compared with NAD ones (3.06 ±0.51, N=11), healthy adults (0.65 ± 0.37, N=9) and umbilical cord blood (2.10 ±0.55, N=5). Moreover, circulating CD11chighCD207+CD1a+cells (18.99 ± 7.38, N=12) are present in active multisystem patients comparedwith NAD patients (2.13 ± 0.40, N=12), healthy adults (0.74 ± 0.29, N=8) andumbilical cord blood (2.76 ± 1.11, N=4).Conclusions: CD11b fraction is increased in active disease and interestinglymonocytes expressing CD207 as well as DCs expressing CD207/CD1a suggest apotential precursor role in AD patients with multifocal lesions or multisysteminvolvement.