Biomedical subjects

J W Joh

Publications and source records attributed to J W Joh.

At least 37 records · Page 2Linked to original sources

PubMed2004

Polymerase chain reaction for the diagnosis of human polyomavirus-associated nephropathy in renal transplant recipients.

Human polyomavirus type BK may be related to interstitial nephropathy or renal-allograft dysfunction. Patients with nephropathy due to infection with human polyomavirus may be identified early using the polymerase chain reaction(PCR). We attempted to evaluate whether the positive response in the PCR test of BK virus DNA in the plasma of renal transplant recipients affects the function of the renal allograft. Seventy-seven patients were prospectively analyzed according to the operative sex, age, sources of allograft, serum creatinine levels during PCR test for BK virus, postoperative type of immunosuppressant, and presence of graft rejection. Two groups were distinguished according to the PCR result for BK virus: group 1 (n = 12) positive PCR reaction and group 2 (n = 65) negative reaction. The mean follow-up was 32.6 weeks. The incidence of positive PCR tests for BK virus replication after renal transplantation was 15.6%. Decoy cells in the urine were detected in 20.7%. The incidence of BK virus nephropathy was 1.3%. The mean serum creatinine levels of group 1 and 2 at the time of the PCR tests were 1.34 and 1.22, respectively. The rejection rates in group 1 and 2 were 8% and 4.5%, respectively (P > .05). We consider that a PCR assay to detect BK virus in renal recipients blood may be useful to identify patients at risk for nephropathy. It may serve as a noninvasive indicator of BK virus replication, although this study is limited by the short follow-up and small numbers.

Adolescent↗

PubMed2004

Changes in expression of T-cell activation-related molecules and cytokines during tolerance induction in an allogeneic skin transplantation murine model.

Bone marrow transplantation after treatment with busulfan and costimulatory blockade with monoclonal antibodies (mAb) cytotoxic T lymphocyte antigen 4 (CTLA4)-Ig and anti-CD154 mAb or two-signal blockade using anti-CD45RB and anti-CD154 mAb are nonmyeloablative treatment regimens for allogeneic transplantation. There may be differences in the mechanisms of donor cell engraftment and reactive cell deletion by which these regimens induce donor-specific tolerance. Therefore, this study was performed to investigate changes in T cells and cytokines during tolerance induction toward allogeneic skin grafts. BALB/c and C57BL/6 mice were used as donors and recipients, respectively. Skin and bone marrow transplantations were performed and busulfan was administered. Three groups were treated with mAb as follows: group 1, anti-CD154 mAb; group 2, anti-CD154 plus anti-CD45RB mAb; and group 3, anti-CD154 mAb plus CTLA4-Ig. The proportions of CD4+ or CD8+ T cells and the expression of CD45RB isoforms on splenocytes were measured using flow cytometry and the production of cytokines by CD4+ T cells using enzyme-linked immunosorbent assay. Group 2 showed a significant reduction in the proportions of CD8+ T cells and CD45RB high isoforms compared with groups 1 and 3. The levels of interleukin (IL)-2 and IL-4 in group 2 were lower and higher than those of groups 1 and 3, respectively. In conclusion, the combined use of anti-CD154 and anti-CD45RB mAb decreases the CD8+ T-cell population and the expression of CD45RB, resulting in a Th2 cytokine profile, which may be a characteristic mechanism leading to donor cell engraftment and reactive cell deletion for donor-specific tolerance.

Animals↗

PubMed2004

Effect of panel-reactive antibody positivity on graft rejection before or after kidney transplantation.

INTRODUCTION: Because it is well known that kidney transplant recipients with preformed lymphocytotoxic antibodies against HLA antigens have increased graft rejection rates, a serological crossmatch is routinely performed before kidney transplantation. But, the presence of these antibodies is not routinely monitored after transplantation. We investigated the panel-reactive antibody (PRA) response to know whether variations before or after kidney transplantation were associated with graft rejection. METHODS: We prospectively analyzed sera from 350 renal allograft recipients from September 1998 to March 2003. Pretransplantation and posttransplantation sera at 3 or 5 weeks postoperatively were tested in PRA. Recipients were stratified into 3 groups according to their PRA levels group I, PRA = 0; group II, PRA = less than 50%, and group III, PRA = more than 50%. RESULTS: The total graft rejection rate among 350 recipients was 9.4% (n = 33). Twenty-four pretransplantation PRA-positive recipients had a graft rejection rate of 20.8% (n = 5), compared with an 8.6% (n = 28) rate among 326 pretransplantation PRA-negative recipients. Six of 24 posttransplantation PRA-positive recipients (25%) experienced a graft rejection versus 27 (8.3%) of 326 posttransplantation PRA-negative subjects. Among the pretransplantation PRA stratae, the rejection rate in group III was 25% (1 of 4) versus 20% (4 of 20) in group II and 8.6% (28 of 326) in group I (P < .05). According to the postransplantation PRA level, 37.5% (3 of 8) in group III versus 18.8% (3 of 16) in group II and 8.3% (27 of 326) in group I (P < .05) had a graft rejection. CONCLUSION: Our study suggests that the PRA response pretransplantation and in the early posttransplantation period correlates with the kidney allograft rejection rate.

Adolescent↗

PubMed2004

Posttransplantation lymphoproliferative disorder in pediatric liver transplantation.

INTRODUCTION: The aim of this study was to evaluate the clinical features of risk factors for posttransplantation lymphoproliferative disorder (PTLD) in pediatric liver transplantation. MATERIALS AND METHODS: Between June 1996 and June 2002, among 41 pediatric patients who underwent liver transplantation, 7 died in the postoperative period. Thirty-five patients, including 1 patient who died of PTLD, were reviewed. Based on the serology results, patients were divided into a high-risk group (EBV-naive recipients of EBV-positive grafts) and a low-risk group (patients other than those in the high-risk group). RESULTS: Five of 41 patients (12.2%) developed PTLD. All of them belonged to the high-risk group. The incidence of PTLD in the high-risk group was 31.3% (5 of 16). The mean duration between operation and diagnosis for PTLD was 9.8 months. Primary EBV infection developed at a median of 6 months after transplantation. Three of 5 patients developed rejection before the diagnosis of PTLD. One patient was diagnosed with laryngeal and gastrointestinal PTLD, whereas the other 4 had gastrointestinal PTLD. They experienced the following symptoms and signs: anemia (100%), hypoalbuminemia (100%), fever (80%), diarrhea (80%), gastrointestinal bleeding (80%), and anorexia (60%). CONCLUSION: The common features of PTLD development were as follows: (1) EBV-positive donors placed into EBV-naive recipients, (2) primary EBV infection approximately 6 months after transplantation, (3) young age, 1 year old at operation, and (4) requirement for intensive posttransplantation immunosuppression.

Child↗

PubMed2004

Prevention of de novo hepatitis B infection from HbcAb-positive donors in living donor liver transplantation.

Hepatitis B virus (HBV) prophylaxis is necessary to prevent de novo hepatitis B infection from HbcAb-positive donors. However, which protocol is more effective is somewhat controversial. Also, it is uncertain whether it is necessary to administer HBV prophylaxis for HbsAb-positive recipients. This study attempted to determine whether it is necessary to administer HBV prophylaxis for HbsAb-positive patients and to evaluate the efficacy of an HBIG monotherapy protocol. From May 1996 to July 2001, among 128 donors examined for HbcAb, 58 donors (45.3%) were HbcAb-positive. Eighteen HbcAb-positive grafts were transplanted to HbsAg-negative recipients. The 4 patients who died of unrelated causes were excluded from this study. Of 14 study cases, 12 recipients were HbsAb-positive, and 2 were HbsAb-naive. Prior to late 1998, we used HBV vaccination only for de novo infection prophylaxis. However, starting from December 1998, HBIG was administered from the time of the liver transplantation regardless of HBsAb positivity. The overall rate of de novo HBV infections from HbcAb-positive donors was 21.4% (3 of 14). All 3 recipients without HBIG prophylaxis presented with de novo HBV infections. Two were HbsAb-positive preoperatively. No de novo HBV infections occurred among recipients with HBIG prophylaxis. Therefore, it is essential to administer HBV prophylaxis even for vaccinated HbsAb-positive patients. HBIG monotherapy is effective to prevent de novo hepatitis B infections from HbcAb-positive donors in living donor liver transplantation.

Child↗

PubMed2004

Can we expand the Milan criteria for hepatocellular carcinoma in living donor liver transplantation?

INTRODUCTION: The Milan criteria, namely, tumors 5 cm or less in diameter in patients with single hepatocellular carcinoma (HCC), no more than 3 tumor nodules, and each 3 cm or less in diameter in patients with multiple tumors, are accepted for cadaveric liver allocation. However, in living donor liver transplantation (LDLT), graft donation may only depend on the donor's intention. The aim of this study was to elucidate the feasibility of Milan criteria in LDLT. MATERIALS AND METHODS: From January 2001 to December 2002, 46 cases of liver transplantation (LT) for HCC included 5 hospital mortalities and 3 cadaveric transplantations, all of which were excluded. We classified the patients into Group I cases that met the Milan criteria and Group II cases that did not meet the Milan criteria. The analyses examined tumor-related risk factors affecting recurrence and survival, such as tumor size, number of tumor nodules, and presence of microvascular and macrovascular invasion. RESULTS: Twenty-one cases belonged to Group I and 17 to Group II. There was no significant difference in the recurrence or survival rates between Groups I and II. The risk factors affecting recurrence were macrovascular invasion and tumor size (5 cm). The number of tumor nodules and microvascular invasion did not appear to affect recurrence. The risk factor affecting survival was macrovascular invasion. CONCLUSION: We suggest that in selected cases the Milan criteria could be extended to increase the number of tumor nodules as long as the HCC were small and did not macrovascular invasion.

Cadaver↗

PubMed2004

Small-for-size graft in adult living-donor liver transplantation.

In the era of living donor liver transplantation (LDLT), graft size is related to recipient prognosis. This study was performed to compare the clinical outcomes according to the graft-to-recipient weight ratio (GRWR) in adult LDLT. Seventy-nine adult patients who had undergone LDLT between June 1997 and June 2002 were retrospectively analyzed. The patients were divided into two groups according to the GRWR (group I, GRWR < 0.8%, n = 11; group II, GRWR > or = 0.8%, n = 68). The mean follow-up period was 19.4 (range 1 to 48) months. The recipients were 62 men (78.5%) and 17 women (21.5%) of mean age 45.2 (range 18 to 63) years. The overall patient survival rates were 74.7% at 1 year and 70.7% at 2 years. The patient survival rate in group I was 54.6% at 1 year and 40.9% at 2 years, whereas that in group II was 77.9% at 1 year and 75.3% at 2 years, showing a significant difference (P = .03). There were no significant differences in postoperative total bilirubin, transaminase enzyme level, prothrombin time (INR), portal vein flow on Doppler sonography, amount of ascites through the drain, complications, or acute rejection rates between the two groups. In conclusion, the minimum acceptable graft size in an adult-to-adult LDLT is GRWR of 0.8%. This study suggests that careful postoperative management and/or technical modifications during surgery are necessary, because small-for-size grafts (GRWR < 0.8%) result in lower patient survival rates.

Adult↗

PubMed2003