Kombination von Y-FISH und Immunfluoreszenz zum Nachweis eines „lymphoendothelialen“ Chimärismus in Sinuswandzellen von Lymphknoten nach gegengeschlechtlicher Knochenmarktransplantation

Sinus-lining cells (SLC) of lymph nodes (LN) are referred to as
(immune-accessory) dendritic cells (DC) and as such, they are part
of the Monocyte Macrophage System (MMS). Chimerism of various kinds
of DC after sex-mismatched stem cell transplantation (SCT) has been
reported, but data on chimerism of SLC have not been available so
far. We examined 13 LN of different female individuals after
sex-mismatched SCT, using a combined podoplanin immunostain and
Y-FISH on single section slides. Twelve out of 13 LN contained
chimeric cells, obviously predominantly lymphocytes, and eleven LN
stained positive with podoplanin in SLC. In one of the LN
simultaneously podoplanin-marked SLC revealed Y-chromosomal
chimerism. Our results demonstrate that bone marrow derived cells
are capable of regenerating SLC, at least at low frequency. These
bone marrow derived cells are most likely hematopoietic stem cells
(HSC) differentiating into blood monocytes which then form SLC, and
after antigen contact SLC might, again, differentiate into FDC.