Tissue chimerism in systemic lupus erythematosus is related to injury.
BACKGROUND
Chimerism indicates the presence of cells from one individual in another individual, and has been associated with several autoimmune diseases. Although this finding may point towards a role for chimerism in the induction of SLE, it could also indicate that chimerism is the result of repair mechanisms after injury.


OBJECTIVE
To perform a post-mortem investigation for the presence of chimerism in 48 organs from seven women with SLE and establish whether there was a relationship between chimerism and injury.


METHODS
Chimeric male cells in female tissue specimens were identified by in situ hybridisation of the Y-chromosome. Organs were categorised into four different groups according to injury experienced.


RESULTS
were compared with those for unaffected control organs. Results: Chimerism was found in all seven patients with SLE. Y-chromosome-positive cells were present in 24 of 48 organs from women with SLE, which was significantly more than in control organs (p<0.001). Chimerism occurred more often in organs from patients with SLE who had experienced injury than in normal control organs, irrespective of whether the injury experienced was SLE-related, non-SLE-related or both.


CONCLUSIONS
This is the first report of the distribution of chimerism in a large number of organs from women with SLE. It shows that the occurrence of chimerism is related to injury. The data support the hypothesis that tissue chimerism is the result of a repair process.
Kremer Hovinga
Idske C L
IC
Department of Pathology, Leiden University Medical Center, P0-14, PO Box 9600, 2300 RC Leiden, the Netherlands. i.c.l.kremer-hovinga@lumc.nl
Koopmans
Marije
M
Baelde
Hans J
HJ
de Heer
Emile
E
Bruijn
Jan A
JA
Bajema
Ingeborg M
IM
D001323:Autoantibodies / Q000276:immunology; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D046528:Chimerism; D041322:Chromosomes, Human, Y; D005260:Female; D006801:Humans; D017403:In Situ Hybridization / Q000379:methods; D007668:Kidney / Q000473:pathology; D008099:Liver / Q000473:pathology; D008168:Lung / Q000473:pathology; D008180:Lupus Erythematosus, Systemic / Q000235:genetics* / Q000276:immunology / Q000473:pathology; D008198:Lymph Nodes / Q000473:pathology; D008297:Male; D009206:Myocardium / Q000473:pathology; D012867:Skin / Q000473:pathology; D013154:Spleen / Q000473:pathology; D013961:Thyroid Gland / Q000473:pathology; D013997:Time Factors
D001323:Autoantibodies