Donor DNA is detected in recipient blood for years after kidney transplantation using sensitive forensic medicine methods.

BACKGROUND: Transplanted vascularized organs shed passenger cells, normal constituents of whole organs, that migrate to recipient lymphoid tissues and produce microchimerism. These cells lyzed by recipient cytotoxic cells release cellular organelles into the recipient circulation. In addition, warm and cold ischemia as well as immune rejection of the transplanted organ or tissue bring about destructive changes in the graft parenchymatous cells. The knowledge of the fate of donor DNA distributed in passenger cells and in fragments of disrupted nuclei as well as the role of recipient cells internalizing donor DNA could give some insight into the mechanism of graft destruction and immunization or tolerance to donor antigens. MATERIAL/METHODS: In this study we provide evidence that forensic medicine testing of polymorphic genes for phospholipase A2, cytochrome P450 and locus D1S80 may be useful for the detection of donor DNA microchimerism in kidney transplant recipients in sex-matched combinations as well as previous blood transfusion recipients. RESULTS: Donor DNA was detected in recipient whole blood even 2 years after kidney transplantation. CONCLUSIONS: The biological significance of our findings is not clear. We speculate that donor DNA fragments in recipient immune cells may play a role in the immunization/tolerance process to allogeneic antigens.

[The molecular characteristic of Staphylococcus aureus and Staphylococcus epidermidis strains isolated from clinical sources]. / Charakterystyka molekularna szczepów Staphylococcus aureus i Staphylococcus epidermidis wyizolowanych z materialu klinicznego.

The aim of study was the molecular characteristic of S. aureus and S. epidermidis isolates obtained from skin surface, wounds, deep tissues of hospitalized patients and from skin surface of non-hospitalized patients. Genes encoding virulence factors were examined using PCR reaction and specific primers. Genes encoding adhesinsfnbA and cna and gene eta for epidermolytic toxin were mostly present in S. aureus isolates coming from wounds and deep tissues compared to these from skin surface. Gene atlE encoding autolysin of S. epidermidis was detected in all studied isolates, whereas gene icaAB was present in almost all isolates. Comparison of results obtained by PCR and conventional method of the resistance to methicillin estimation showed discrepances suggesting the need for using of both methods in some clinically difficult cases of S. aureus infection.