Role of bcl-2 mRNA in homeostatic proliferation in circulating T-cells in human liver transplant patients after T-cell depletion.
BACKGROUND
Prolonged T-cell depletion after liver transplantation leads to life-threatening infections. Members of the anti-apoptotic Bcl-2 gene family can maintain T-cell viability. T-cell numbers and their Bcl-2 expression following living donor liver transplantation (LDLT) were analyzed in 108 surviving and 13 deceased recipients.


METHODS
Bcl-2 mRNA levels and phenotypic changes of T-cells were examined by quantitative PCR and by measuring expression of CD45RO and CCR7.


RESULTS
Based on the restoration of peripheral T-cell numbers, the 108 surviving recipients were classified into three groups. All recipients showed T-cell depletion, down to approximately 30% of pretransplant levels within 3 h of graft reperfusion. In Group I, the T-cell numbers were rapidly restored to pretransplant levels, within 5 days, with a rapid decrease in Bcl-2 mRNA levels immediately after LDLT. In Group II, the T-cell numbers were restored to normal levels by 19 days, with down-regulation of Bcl-2 mRNA. In Group III, the T-cell numbers were maintained at low levels for much longer, with high levels of Bcl-2 mRNA. In all three groups of recipients, there was statistically significant (r = -0.78) inverse correlation between T-cell numbers and Bcl-2 mRNA.


CONCLUSIONS
For successful transplantation, homeostatic restoration of T-cells must occur as soon as possible. Evaluation of peripheral T-cell numbers and of Bcl-2 expression may have therapeutic potential in identifying those transplant patients who face increased risk of infection.
Sato
Hiroshi
H
Division of Bioscience, Shiga University of Medical Science, Seta, Otsu, Shiga 520-2192, Japan. satoh@belle.shiga-med.ac.jp
Ozawa
Kazue
K
Iwata
Shingo
S
Kaihara
Satoshi
S
Ogura
Yasuhiro
Y
Fujimoto
Yasuhiro
Y
Ono
Masako
M
Hodohara
Keiko
K
Uemoto
Shinji
S
Nakamura
Hajime
H
Takai
Kenji
K
Tanaka
Koichi
K
D000293:Adolescent; D000328:Adult; D001773:Blood Cells / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006706:Homeostasis; D006801:Humans; D007223:Infant; D007239:Infections / Q000097:blood / Q000209:etiology / Q000401:mortality; D016031:Liver Transplantation / Q000009:adverse effects; D019520:Living Donors; D018655:Lymphocyte Count; D008212:Lymphocyte Depletion / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics*; D012333:RNA, Messenger / Q000097:blood*; D013601:T-Lymphocytes / Q000473:pathology*
D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger