title: Detection of secretory IgM in tears during rhino-conjunctivitis.
abstract: BACKGROUND
  With various methods, secretory immunoglobulin M (sIgM) was assessed in tears of patients with rhino-conjunctivitis.
  
  
  METHODS
  Tears were analyzed by microimmunoelectrophoresis (MIE), size-exclusion high-pressure liquid chromatography (SE-HPLC), sodium dodecyl sulphate (SDS) electrophoresis and isoelectric focusing.
  
  
  RESULTS
  Only very small traces of serum IgM could be found in tears of healthy volunteers. MIE showed that tear sIgM is different from serum IgM. The former migrates in the direction of the anode, while serum IgM migrates to the cathode. The SDS electropherogram of a number of patients showed an additional strong band of the sIgM mu-chain of approximately 68 kDa, after rhino-conjunctivitis. SE-HPLC showed two additional peaks for these patients, at 10.97 min and at 12.94 min, which were attributed to tear sIgM. The former peak consists of a complex of four sIgM molecules. One year later the chromatograms of the former rhino-conjunctivitis patients did not show any peak of sIgM in SE-HPLC.
  
  
  CONCLUSIONS
  Serum IgM of a molecular weight (MW) 970 kDa appears only in normal tears at very low concentrations, as a result of transudation from the serum. In contrast, sIgM is synthesized during rhino-conjunctivitis in high concentrations in the human lacrimal glands and the conjunctiva. These increased levels of tear sIgM are due to stimuli for specific protein synthesis.
authors.affiliation: Department of Experimental Ophthalmology, University of Bonn, Sigmund-Freud-Strasse 25, 53105 Bonn, Germany. jbours@freeler.nl
authors.forename: Johan
authors.initials: J
authors.lastname: Bours
authors.forename: Claudia
authors.initials: C
authors.lastname: Reitz
authors.forename: Jürgen
authors.initials: J
authors.lastname: Strobel
authors.forename: Winrich
authors.initials: W
authors.lastname: Breipohl
mesh_terms: D002851:Chromatography, High Pressure Liquid; D003236:Conjunctivitis, Viral / Q000276:immunology*; D004591:Electrophoresis, Polyacrylamide Gel; D005136:Eye Proteins / Q000032:analysis*; D006801:Humans; D007122:Immunoelectrophoresis; D007075:Immunoglobulin M / Q000032:analysis*; D007525:Isoelectric Focusing; D010850:Picornaviridae Infections / Q000276:immunology*; D012229:Rhinovirus / Q000276:immunology*; D013666:Tears / Q000276:immunology*
chemical_list: D005136:Eye Proteins; D007075:Immunoglobulin M; C033027:secretory IgM; C042434:tear proteins