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Proteomic analysis of plasma from patients with systemic lupus erythematosus: Increased presence of haptoglobin α2 polypeptide chains over the α1 isoforms
Author(s) -
Pavón Esther J.,
Muñoz Pilar,
Lario Antonio,
Longobardo Victoria,
Carrascal Montserrat,
Abián Joaquín,
Martin Ana B.,
Arias Salvador A.,
CallejasRubio JoséLuis,
Sola Ricardo,
NavarroPelayo Francisco,
RayaAlvarez Enrique,
OrtegoCenteno Norberto,
Zubiaur Mercedes,
Sancho Jaime
Publication year - 2006
Publication title -
proteomics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.26
H-Index - 167
eISSN - 1615-9861
pISSN - 1615-9853
DOI - 10.1002/pmic.200500404
Subject(s) - haptoglobin , phenotype , lupus erythematosus , immunology , systemic lupus erythematosus , allele , medicine , allele frequency , gene isoform , systemic disease , connective tissue disease , biology , autoimmune disease , disease , antibody , gene , genetics
Abstract In the present study plasma samples from 15 systemic lupus erythematosus (SLE) patients and 16 healthy controls of initially unknown haptoglobin (Hp) phenotype were separated by 2‐DE, and tryptic digests of the excised Hpα polypeptide chain spots were analyzed by MALDI‐TOF‐MS. Selected tryptic peptides were sequenced by nano‐(n)ESI‐IT MS/MS. The six major Hp phenotypes were present, although with distinct frequencies in controls and SLE patients. Thus, there were an increased proportion of SLE patients with Hp 2–2, or Hp 2–1S phenotypes. The Hp phenotype distribution resulted in allele frequencies of 0 625 (Hp 2 ) , 0.281 (Hp 1S ) , and 0.093 (Hp 1F ) in healthy controls, correlating fairly well with the allele frequencies of European populations. In contrast, the Hp allele frequencies of the SLE patients were 0.733 (Hp 2 ) , 0.233 (Hp 1S ) , and 0.033 (Hp1 1F ) , which clearly indicated an increased frequency of Hp 2 , a similar proportion of Hp 1S and a diminished proportion of Hp 1F in SLE patients compared with that in healthy controls. Preferential Hpα2 expression in SLE patients may contribute to some of the clinical manifestations of the disease such as hypergammaglobulinemia, systemic vasculitis, and cardiovascular disorders.