Genetic analysis of hereditary gingival fibromatosis using whole exome sequencing and bioinformatics.

OBJECTIVES: Our study aims to identify genetic variants associated with hereditary gingival fibromatosis (HGF) by applying whole-exome sequencing (WES) and bioinformatics analyses such as gene set enrichment analysis (GSEA) and protein functional network study. SUBJECTS AND METHODS: Two affected siblings whose grandparents and parents have normal gingiva were chosen for our investigation. Saliva collected from the patients and their parents were used for WES. GSEA and protein functional network study were performed to find gene groups in a biological coordination which are associated with HGF. RESULTS: Genetic variants for homozygotes and compound heterozygotes were analyzed and translated into 845 genes. The result from protein functional network study showed that these genetic variants were mainly observed in genes affecting fibronectin as well as the immune and autoimmune system. Additionally, three mutated genes in our HGF patients, TMCO1, RIN2, and INSR, were found through human phenotype ontology (HPO) to have potential to contribute to gingival hyperplasia. CONCLUSIONS: Genetic analysis of HGF in this study implicated mutations in fibronectin and the immune system as triggering abnormal gingival fibromatosis.

Rhabdomyolysis associated with cytomegalovirus infection in kidney transplant recipients.

Rhabdomyolysis is a pathological syndrome caused by skeletal muscle cell damage that affects the integrity of the cellular membrane and leads to the release of toxic intracellular constituents into the bloodstream. Although cytomegalovirus (CMV) has rarely been reported as a cause of rhabdomyolysis, CMV infection could be considered as a possible cause because of its clinical significance in kidney transplant recipients (KTRs). We report 2 cases of rhabdomyolysis associated with CMV infection in KTRs. A 64-year-old woman (Case 1) and a 65-year-old man (Case 2), who had each received a kidney from a living unrelated donor, were admitted with complaints of weakness in both legs and myalgia. Laboratory findings revealed highly increased creatine phosphokinase and myoglobinuria. In both cases, no recent alterations of medications had occurred, and other causes of rhabdomyolysis--such as trauma, alcohol, drugs, and electrolyte abnormalities - were excluded. CMV pp65 antigen was positive, and patients were diagnosed with rhabdomyolysis associated with CMV infection. Both patients recovered without complications after ganciclovir treatment. In conclusion, CMV infection should be considered as a possible cause of rhabdomyolysis in KTRs.

Successful withdrawal of antiviral treatment in kidney transplant recipients with chronic hepatitis B viral infection.

BACKGROUND: The optimal duration of antiviral therapy for kidney transplant recipients (KTR) with chronic hepatitis B virus (HBV) infection remains unclear. We reported the long-term outcomes after withdrawal of antiviral agent in KTR with chronic HBV infection. METHODS: We retrospectively investigated the hepatitis B surface antigen (HBsAg)-positive KTR with antiviral agents between January 2002 and January 2012. Antiviral treatments were withdrawn in patients who met all of the following 7 criteria: (i) no clinical and histologic evidence of cirrhosis, (ii) normal liver biochemistry, (iii) negative for both HBV DNA and hepatitis B envelope antigen (HBeAg), (iv) no resistance to antiviral agent, (v) antiviral therapy > 9 months, (vi) maintenance dosage of immunosuppressant for > 3 months, and (vii) no history of acute rejection during recent 6 months. All patients were followed regularly at approximately 3-6 months for liver enzyme, viral markers, and HBV DNA level after antiviral withdrawal. RESULTS: Among a total of 445 KTR, 14 HBsAg-positive patients were included in this study. Antiviral agents were used, with lamivudine in 11 patients, and with adefovir, entecavir, and telbivudine in 3 patients, respectively. Discontinuation of antiviral agent was attempted in 6 (42.9%) of 14 patients who satisfied the criteria. The median duration of antiviral therapy before withdrawal was 14.3 months (range, 9-24 months). Four (66.7%) of 6 patients were successfully withdrawn and remained negative for HBV DNA for a median 60.5 months (range, 47-82 months). The baseline HBV DNA level was not related to maintenance of remission after withdrawal. Two reactivated patients resumed antiviral treatment immediately, with subsequent normalization of HBV DNA. During the follow-up, 1 patient developed hepatocellular carcinoma; however, no patient death or graft failure was reported for all HBsAg-positive KTR. CONCLUSIONS: Antiviral therapy can be discontinued successfully and safely in selected KTR with chronic HBV infection, after complete suppression of HBV and sufficient duration of antiviral therapy.

Mycobacterium kansasii pericarditis in a kidney transplant recipient: a case report and comprehensive review of the literature.

Mycobacterium kansasii is the second most common non-tuberculous mycobacteria in kidney transplant recipients (KTRs) and has been reported to cause disseminated infection in KTRs. We report the first case to our knowledge of M. kansasii pericarditis after kidney transplantation in a 54-year-old man. The patient was admitted with a 2-month history of intermittent fever and myalgia, treated with oral prednisolone and mycophenolate mofetil prior to admission. Chest computed tomography showed enlarged mediastinal lymph node and small amount of pericardial effusion. Mediastinoscopic biopsy of mediastinal lymph node revealed reactive hyperplasia, without evidence of granuloma, but acid-fast bacilli stain of pericardial fluid reported positive finding and pericardial fluid culture identified M. kansasii. The patient has been treated successfully with rifabutin-based combination therapy. All available cases of M. kansasii infection in kidney transplant patients and M. kansasii pericarditis in human immunodeficiency virus-infected patients are comprehensively reviewed.

Near-infrared spectroscopy as a possible device for continuous monitoring of arterial carbon dioxide tension during cardiac surgery.

BACKGROUND: Insufflation of carbon dioxide (CO(2)) to the operative field has been used to prevent major organ injury attributed to air embolisms in cardiac surgery. However, it may be preferable to avoid hypercapnia induced by CO(2) insufflation, owing to its potentially harmful effect. To investigate the effectiveness of near-infrared spectroscopy (NIRS) as a possible method for continuous monitoring of arterial CO(2) tension during cardiac surgery, we evaluated the correlation between the change in arterial CO(2) tension and the change in regional cerebral oxygen saturation (rScO(2)) obtained from NIRS in as controlled a condition as possible. METHODS: Thirty patients who underwent surgical correction for atrial or ventricular septal defects were enrolled in this study. Patients who had pulmonary hypertension or other intracardiac anomalies were excluded. Anesthetic and cardiopulmonary bypass (CPB) management were conducted according to our standard institutional practice. Data obtained from arterial blood gas analyses and corresponding regional cerebral oxygen saturation (rScO(2)) recorded from NIRS before and after the insufflations of CO(2) during CPB were used for analysis. RESULTS: The change in arterial CO(2) tension correlated with the change in rScO(2) in the left hemisphere (r = 0.681, p <0.001, y = -1.393 + 0.547x) and right hemisphere (r = 0.690, p <0.001, y = -1.999 + 0.486x). To control the effects of other variables, including hematocrit and temperature, these relationship were not reduced (left hemisphere: r=0.678, p<0.001; right hemisphere: r=0.634, p<0.001). CONCLUSIONS: Since the change in regional cerebral oxygen saturation was correlated with the change in arterial CO(2) tension during mild hypothermic CPB, NIRS might be a possible non-invasive method for monitoring of arterial CO(2) tension without incurring additional cost in this setting.

Interleukin-18, transforming growth factor-ß, and vascular endothelial growth factor gene polymorphisms and susceptibility to primary glomerulonephritis.

Several studies have showed an association of gene polymorphisms with the development of glomerulonephritis (GN). We investigated the effects of gene polymorphisms on the development of GN by analyzing polymorphisms in the interleukin (IL)-18, transforming growth factor (TGF)-ß, and vascular endothelial growth factor (VEGF) genes in Korean patients with primary GN. The study included 146 normal subjects (controls) and 100 patients diagnosed with primary GN by kidney biopsy. The gene polymorphisms A-607C and G-137C in IL-18, C-509T and T869C in TGF-ß1, and C-2578A and C405G in VEGF were investigated in DNA extracted from peripheral blood. Significant differences were observed between the GN and control groups in the genotype and allele frequencies of A-607C IL-18 and C405G VEGF. The frequencies of the IL-18-607CC genotype [P = 0.001, odds ratio (OR) = 2.473] and the VEGF 405GG genotype (P = 0.001, OR = 2.473) were significantly increased in the GN group. The combination of IL-18-607CC+ and VEGF 405GG+ genotypes had a higher risk for developing GN in comparison with the combination of IL-18-607CC- and VEGF 405GG- genotypes (P < 0.001, OR = 8.642). In the haplotype analysis of the IL-18 gene, the CG haplotype was significantly more frequent in the GN group than the control group (61.5% vs 46.9%, P = 0.002). These results show that the -607CC genotype of the IL-18 gene and the 405GG genotype of the VEGF gene are associated with susceptibility to and the development of primary GN.

Association of C-509T and T869C polymorphisms of transforming growth factor-beta1 gene with chronic allograft nephropathy and graft survival in Korean renal transplant recipients.

PURPOSE: Transforming growth factor-beta1 (TGF-beta1) has been associated with the promotion of renal allograft interstitial fibrosis and thereby chronic allograft nephropathy (CAN). The literature on TGF-beta1 polymorphisms and their importance in graft survival and CAN is not conclusive. METHODS: TGF-beta1 gene polymorphisms (C-509T and T869C) were examined in a group of 207 Korean renal transplant recipients using real-time polymerase chain reaction assays. The CAN group (n = 18) was defined by a typical biopsy confirming CAN or chronic calcineurin inhibitor nephrotoxicity. The rest of the patients were classified into the No CAN group (n = 189). RESULTS: No significant differences were observed in the genotype distributions of both C-509T and T869 polymorphisms between the two groups. Allele frequencies and age-, sex-, HLA mismatch-adjusted odds ratio of each genotype as assessed by logistic regression analysis were also not significantly different between the two groups. Linkage disequilibrium coefficients between polymorphisms indicated that investigated polymorphisms of TGF-beta1 (D' = 0.98) were in tight linkage. However, there were no significant differences in the frequencies of the reconstructed haplotypes between the two groups. Kaplan-Meier method and log-rank tests did not indicate any statistically significant effects of TGF-beta1 gene polymorphisms on graft survival. CONCLUSION: TGF-beta1 gene polymorphisms (C-509T, T869C) are not significantly associated with an increased risk of development of CAN and graft survival in Korean renal transplant recipients.

Distribution of Anti-ABO Immunoglobulin G Subclass and C1q Antibody in ABO-incompatible Kidney Transplantation.

INTRODUCTION: To investigate the correlation between serum anti-ABO immunoglobulin G (IgG) and IgG subclasses, anti-ABO IgG subclasses were measured by flow cytometry (FCM) in ABO-incompatible (ABOi) kidney transplant recipients. We also evaluated baseline anti-ABO C1q antibody. METHOD: Baseline anti-ABO IgG titers were measured by both FCM and column agglutination technique methods in 18 ABOi kidney transplant recipients. The mean florescence intensity (MFI) ratios of baseline anti-ABO IgG subclasses and anti-ABO C1q antibody were obtained by FCM and followed-up after rituximab treatment, each plasmapheresis (PP) session, and kidney transplantation. Correlation between the values of IgG subclass and total IgG titer was analyzed. RESULTS: The baseline MFI ratios of total IgG, IgG1, IgG2, IgG3, and IgG4 were 202.46, 62.41, 30.01, 1.04, and 1.13, respectively. The MFI ratios of IgG1, IgG2, and total IgG measured at baseline and pre-PP were positively correlated with the baseline ABO titer was measured using the column agglutination technique. The numbers of PP sessions to reach the target titer were correlated with the baseline IgG and IgG1 levels. IgG1 and IgG2 as well as total IgG were removed effectively after serial PP. Anti-ABO C1q antibody was neither detected nor correlated with total IgG and any IgG subclasses. CONCLUSIONS: Our findings suggest that IgG1 and IgG2 are the dominant IgG subclass in ABOi kidney transplant recipients. Baseline levels of IgG1 and IgG2 were correlated with baseline total IgG titer. However, anti-ABO C1q antibody was not detected in the present study.

Metabolomics Study for Identification of Potential Biomarkers of Long-term Survival in Kidney Transplantation Recipients.

BACKGROUND: The recent progress and appropriate use of immunosuppressive drugs have considerably improved the short-term survival in kidney transplantation recipients (KTRs). The development of new strategies to improve long-term survival outcome after kidney transplantation is also becoming important. Although current diagnosis of allograft dysfunction relies on serum creatinine concentration and biopsy, they are nonspecific indicators of allograft function. Therefore, noninvasive, sensitive, and specific biomarkers for the prediction of long-term survival are needed. The aim of this study was to discover potential biomarkers for long-term survival in KTRs through the use of liquid chromatography-tandem mass spectrometry. METHODS: We used the metabolic approach to explore the change of metabolites in the serum of KTRs. Twenty-four KTRs with long-term good survival (LGS) and 10 KTRs with chronic antibody-mediated rejection (CAMR) were included in this study. After quantile normalization with chromatographic data, multivariate statistical analysis was performed. We attempted to analyze metabolic profiling with LGS and CAMR groups. RESULTS: The orthogonal partial least-squares discriminant analysis score plot showed a separation between 2 groups in the principal component. In the corresponding loading plot, 344 metabolites responsible for the separation observed in the score plot were identified (variable influence on projection ≥1.0). We then selected 54 metabolites to compare mass with charge by searching a web database, and 11 compounds were identified. CONCLUSIONS: We found metabolites in serum that differ in LGS and CAMR groups. Further studies are needed to figure out potential metabolomic biomarkers to predict long-term survival in KTRs.

Cystatin C-Based Equation for Predicting the Glomerular Filtration Rate in Kidney Transplant Recipients.

BACKGROUND: Precise monitoring of the glomerular filtration rate (GFR) is needed to estimate the allograft function in kidney transplant recipients (KTRs). The GFR is widely estimated with the use of formulas based on serum cystatin C (SCys) and serum creatinine (SCr) levels. We compared the efficacy of SCys-based equations with that of SCr-based equations to predict the allograft function. METHODS: We calculated the Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI Cr), CKD-EPI creatinine-cystatin C (CKD-EPI Cr/Cys), and CKD-EPI cystatin C (CKD-EP ICys) equations in 70 KTRs. The measured GFR (mGFR) was defined as the GFR estimated by technetium-99m-diethylene triamine pentaacetic acid (99mTc-DTPA) clearance. The accuracy and precision of the equations were compared with the mGFR. The performance characteristics of SCr and SCys were analyzed with the use of receiver operating characteristic (ROC) curves to ascertain the sensitivity and specificity at the cutoff value of <45 mL/min/1.73 m2 DTPA. RESULTS: Overall, MDRD and CKD-EPICys did not show significant differences from mGFR (P = .05 and P = .077, respectively), whereas CKD-EPI Cr and CKD-EPI Cr/Cys significantly underestimated mGFR (P < .001 and P = .005, respectively). In the subgroup of patients with mGFR <45 mL/min/1.73 m2, CKD-EPI Cys showed little bias (P = .122), whereas MDRD significantly underestimated mGFR (P = .037). The area under the ROC curve for predicting mGFR <45 mL/min/1.73 m2 was 0.80 for SCys, which was better than that for SCr at 0.763. CONCLUSIONS: Cystatin C-based equations showed better predictive performance of the allograft function than creatinine-based equations for the KTRs, including patients with lower GFR. Cystatin C level might be a good alternate measurement to monitor the allograft function.

Effect of Changes in Body Mass Index on Cardiovascular Outcomes in Kidney Transplant Recipients.

BACKGROUND: A higher body mass index (BMI) before kidney transplantation (KT) is associated with increased mortality and allograft loss in kidney transplant recipients (KTRs). However, the effect of changes in BMI after KT on these outcomes remains uncertain. The aim of this study was to investigate the effect of baseline BMI and changes in BMI on clinical outcomes in KTRs. METHODS: A total of 869 KTRs were enrolled from a multicenter observational cohort study from 2012 to 2015. Patients were divided into low and high BMI groups before KT based on a BMI cutoff point of 23 kg/m2. Differences in acute rejection and cardiovascular disease (CVD) between the 2 groups were analyzed. In addition, clinical outcomes across the 4 BMI groups divided by BMI change 1 year after KT were compared. Associations between BMI change and laboratory findings were also evaluated. RESULTS: Patients with a higher BMI before KT showed significantly increased CVD after KT (P = .027) compared with patients with a lower BMI. However, among the KTRs with a higher baseline BMI, only persistently higher BMI was associated with increased CVD during the follow-up period (P = .003). Patients with persistently higher BMI had significantly decreased high-density lipoprotein cholesterol and increased hemoglobin, triglyceride, and hemoglobin A1c levels. Baseline BMI and post-transplantation change in BMI were not related to acute rejection in KTRs. CONCLUSIONS: BMI in the 1st year after KT as well as baseline BMI were associated with CVD in KTRs. More careful monitoring of obese KTRs who do not undergo a reduction in BMI after KT is required.

Urinary transforming growth factor-beta-induced gene-h3 (betaig-h3) as a sensitive predictor in chronic cyclosporine nephrotoxicity.

Transforming growth factor (TGF)-beta is involved in the pathogenesis of chronic cyclosporine nephrotoxicity (CyAN). Since the expression of TGF-beta induced gene h3 (betaig-h3) is up-regulated by TGF-beta, we evaluated the potential role of betaig-h3 as a sensitive urinary marker to monitor the progression/regression of chronic CyAN. Urinary betaig-h3 levels were determined using an enzyme-linked immunosorbent assay in nine patients with chronic CyAN and 13 patients with stable graft function. We scored the extent of tubulointerstitial fibrosis (TIF) and using immunoperoxidase labeling, determined betaig-h3 expression in renal tissues of patients with chronic CyAN. Urinary betaig-h3 excretion was higher in chronic CyAN compared to control subjects (173.4+/-26.0 vs 62.6+/-5.0 ng/mg creatinine, P<.01). In chronic CyAN, the degree of TIF correlated with increased urinary betaig-h3 levels (r=.785, P<.05). In kidneys with chronic CyAN, betaig-h3 labeling was more prominent at the basement membranes (BM) of the tubules where inflammatory cells had infiltrated the surrounding interstitium. Moreover, the BM of the atrophied tubules and their surrounding interstitium were strongly labeled. Urinary betaig-h3 levels decreased from 173.4+/-26.0 to 64.9+/-14.4 ng/mg creatinine at 1 month after discontinuation of CyA or reduction in CyA dosage (P<.01) despite unchanged serum creatinine levels. Urinary betaig-h3 levels increased in patients with chronic CyAN and decreased after discontinuation or reduction of CyA dosage. Our results suggested that urinary betaig-h3 levels could be used as a sensitive urinary marker to monitor the progression or regression of chronic CyAN.

Clinical impact of BK virus surveillance on outcomes in kidney transplant recipients.

BACKGROUND: The objective of this study was to investigate the clinical impact of BK virus surveillance on graft injury in kidney transplantation. METHODS: BK viremia in kidney transplant recipients was evaluated by use of plasma quantitative polymerase chain reaction. The prevalence of BK viremia and BK virus-associated nephropathy (BKVAN) and the clinical impact of BK viremia on graft outcomes were assessed. RESULTS: This study took place between January 2008 and June 2013. A total of 213 kidney transplant recipients were included. The prevalence of BK viremia and high BK viremia (≥1 × 10(4) copies/mL) was 66.7% (142/213) and 17.4% (37/213), respectively. A diagnosis of BKVAN was confirmed by means of allograft biopsy in 9 patients (4.2%). The estimated glomerular filtration rate after transplantation was similar in both the low BK viremia (<1 × 10(4) copies/mL) and non-BK viremia groups but was significantly lower in the high BK viremia group after 18 months. In receiver operating characteristic curve analysis, the area under the curve value of plasma polymerase chain reaction was 0.980. We found that a viral load >92,850 copies/mL was able to predict BKVAN with 89% sensitivity and 94.6% specificity. The risk factors for viral loads ≥1 × 10(4) copies/mL were cytomegalovirus infection, steroid pulse therapy, and acute rejection. CONCLUSIONS: High BK viremia was associated with poor graft function after kidney transplantation. The serial monitoring of BK viremia in kidney transplant recipients was helpful in predicting BKVAN and might prevent further progression.

Effect of transient post-transplantation hyperglycemia on the development of diabetes mellitus and transplantation outcomes in kidney transplant recipients.

BACKGROUND: Hyperglycemia occurs frequently after kidney transplantation and may be reversed when the dosage of the immunosuppressive agents is tapered. However, the effect of transient post-transplantation hyperglycemia (PTH) on transplantation outcomes is not well described. METHODS: Kidney transplant recipients without diabetes who underwent kidney transplantation between 2001 and 2012 were enrolled in the study. Transient PTH was defined as recovery from PTH without further antidiabetic therapy and the maintenance of glycated hemoglobin levels <6.5% at 1 year after transplantation. Persistent PTH until 1 year after transplantation was considered to be new-onset diabetes after transplantation (NODAT). The factors associated with increased risk of PTH were analyzed. We compared the development of diabetes mellitus, cardiovascular disease, and other transplantation outcomes among patients with no PTH, transient PTH, and NODAT. RESULTS: Among 176 kidney transplant recipients, 106 (60.2%) developed PTH and 58 (54.7%) of 106 patients with PTH had transient PTH. Older age, high body mass index (BMI), and female gender were independent risk factors for transient PTH. The incidence of diabetes was not significantly different between patients with no PTH and those with transient PTH. The incidence of cardiovascular disease was significantly increased in NODAT group compared with that in no PTH and transient PTH groups. However, the incidences of acute rejection, allograft loss, and patient death were comparable among the three groups. CONCLUSIONS: Transient hyperglycemia after kidney transplantation was found to be associated with older age, high body mass index, and female gender. Transient elevation of blood glucose level did not affect post-transplantation outcomes, including diabetes mellitus and cardiovascular disease. However, patients with NODAT should be carefully monitored for the occurrence of cardiovascular disease.

Application of flow cytometry to measure anti-A/B antibody in ABO-incompatible kidney transplantation.

BACKGROUND: The aim of this study was to compare anti-ABO antibody levels as measured by means of flow cytometry (FCM) with the levels measured with the use of the column agglutination test (CAT), and to evaluate the clinical outcome as it relates to the baseline mean fluorescence intensity (MFI) ratio obtained by FCM. METHODS: We reviewed 21 cases of ABO-incompatible kidney transplantation (ABO-i KT). In these patients, baseline IgG titers were measured with the use of both FCM and CAT methods. We investigated the correlation between levels measured by FCM and those by CAT with the use of correlation coefficients. Patients were classified into a high MFI ratio group (≥200; n = 7) or low MFI ratio group (<200; n = 14). RESULTS: The MFI ratio for the FCM-based method was highly correlated with the titer measured by CAT (r = 0.890; P = .01). The relationship between MFI ratio and CAT titer can be expressed as follows: log (MFI ratio) = 0.879 × log (CAT titer) + 0.298. The number of pre-transplantation rounds of plasmapheresis significantly increased as the baseline MFI ratio increased. The allograft function was immediately recovered and stable. A single case of acute cellular rejection was observed in the low MFI ratio group. CONCLUSIONS: Anti-ABO antibody levels measured by means of the FCM-based method were highly correlated with the levels measured with the use of CAT in cases of ABO-i KT. The decreased level of anti-ABO antibody measured by means of FCM after plasmapheresis suggests its potential as an effective and objective method for assessment of anti-ABO antibody levels.

HLA gene dosage effect on renal allograft survival.

BACKGROUND: Human leukocyte antigen (HLA)-A, HLA-B, and HLA-DR matching has beneficial long-term effects on renal allograft survival. However, the gene dosage effect of mismatched HLA on transplant outcomes is not known. We investigated the HLA gene dosage effects on allograft survival in kidney transplant recipients (KTRs). METHODS: We analyzed HLA typing of KTRs and kidney donors at Kyungpook National University Hospital from January 1982 to December 2012. KTRs were divided into 2 groups: recipients from homozygous HLA donors and recipients from heterozygous HLA donors. Death-censored graft survival of KTRs was compared according to allele state of kidney donors. RESULTS: In this study, 697 KTRs were enrolled. According to Kaplan-Meier analysis, graft survival in KTRs of HLA-DR and HLA-B heterozygous donors was longer than that in KTRs of HLA-DR and HLA-B homozygous donors (P = .007 and P < .0001, respectively). Multivariate Cox proportional hazards model analysis showed that HLA-DR and HLA-B donor homozygosity was an independent risk factor for death-censored graft survival (P = .019 and P = .022, respectively). Death-censored graft survival was not associated with HLA-A and HLA-A, B, DR allele states. CONCLUSIONS: Compared with HLA donor mismatch caused by HLA-DR and HLA-B heterozygosity, HLA donor mismatch caused by HLA-DR and HLA-B homozygosity was associated with significantly increased risk of graft failure. In addition to the number of HLA mismatch between KTRs and donors, the donor allele state should be considered to predict transplant outcomes.

HRAS protooncogene polymorphism and breast cancer.

The potential association of polymorphism in the HRAS protooncogene variable repeat region with susceptibility to cancer has become a controversial topic. A number of studies have produced results that appear inconsistent. We report here a multidisciplinary study with a combined molecular and epidemiological approach, addressing the specific question of the association of rare HRAS alleles and breast cancer. Extensive questionnaire data and peripheral blood for DNA extraction were obtained from 160 cases of incident breast cancer and from two control groups totaling 405 unaffected women from five outpatient clinics in North Carolina between April 1990 and June 1991. Controls were frequency matched to cases on age and race. Our results, adjusted for race and age, showed a positive overall association between the presence of rare HRAS alleles and breast cancer. This relationship was somewhat stronger in control group 2 (odds ratio = 3.0; P < 0.01) than in control group 1 (odds ratio = 2.0; P < 0.05). The relationship was 3-6 times stronger in blacks than in whites. In the case series, rare HRAS alleles were associated with hormone receptor negative tumors. This association was stronger in blacks and younger women. There was no confounding or effect modification by any other breast cancer risk factors. We conclude that rare HRAS alleles are associated with breast cancer and that this association may be stronger in black women than in white women. Rare HRAS alleles may also be related to more aggressive tumors, particularly in blacks and younger women. HRAS alleles have the potential to become a valuable screening biomarker for women at increased risk for breast cancer.

Induction of natural chimerism after retransplantation of the liver in rats.

Immunological aspects after orthotopic rat liver retransplantation (re-OLT) were examined in association with cell migration and mixed chimerism. At day 2 after the first orthotopic liver transplantation (day 0) in the combination of DA (MHC haplotype, RT1a) donor into PVG (RT1c) recipient, the grafted DA liver was removed and a new PVG liver was implanted into the same PVG recipient (re-OLT). In the PVG recipient at various times after the re-OLT, DA-derived antigen and cells were detected using a DA-specific anti-class I mAb R3/13 in conjunction with ELISA, immunoblotting, and immunohistochemistry. The level of soluble class I antigen, which had risen to 270 ng/ml after the first OLT, substantially decreased within 24 hr after re-OLT. Using immunoblotting, DA class I antigen was detected in the PVG recipient's lymphoid organs at day 3 after DA liver grafting and persisted for up to 21 days after the DA liver was replaced by a new PVG liver. Immunohistochemistry on sections of spleen from re-OLT rats showed that the level of migratory cells expressing DA class I correlated with the findings obtained by immunoblotting. While the DA-derived antigen and cells were detected in the re-OLT recipient, the DA-specific inhibition of mixed lymphocyte reaction was observed in re-OLT serum. Our results suggest that the implanted DA liver graft was the source of DA soluble class I antigen, but DA-derived antigen and cells detected in the re-OLT recipient organs could persist for a relatively long time under immunosuppression after the implanted DA liver was removed by re-OLT.

Mitochondrial DNA sequence analysis of four Alzheimer's and Parkinson's disease patients.

The mitochondrial DNA (mtDNA) sequence was determined on 3 patients with Alzheimer's disease (AD) exhibiting AD plus Parkinson's disease (PD) neuropathologic changes and one patient with PD. Patient mtDNA sequences were compared to the standard Cambridge sequence to identify base changes. In the first AD+PD patient, 2 of the 15 nucleotide substitutions may contribute to the neuropathology, a nucleotide pair (np) 4336 transition in the tRNA(Gln) gene found 7.4 times more frequently in patients than in controls, and a unique np 721 transition in the 12S rRNA gene which was not found in 70 other patients or 905 controls. In the second AD+PD patient, 27 nucleotide substitutions were detected, including an np 3397 transition in the ND1 gene which converts a conserved methionine to a valine. In the third AD+PD patient, 2 polymorphic base substitutions frequently found at increased frequency in Leber's hereditary optic neuropathy patients were observed, an np 4216 transition in ND1 and an np 13708 transition in the ND5 gene. For the PD patient, 2 novel variants were observed among 25 base substitutions, an np 1709 substitution in the 16S rRNA gene and an np 15851 missense mutation in the cytb gene. Further studies will be required to demonstrate a causal role for these base substitutions in neurodegenerative disease.

Preemptive treatment of minimal residual disease post transplant in CML using real-time quantitative RT-PCR: a prospective, randomized trial.

Immunotherapy in the form of donor lymphocyte infusions in early-phase relapse might be advantageous as it induces a higher response, but this may be offset by increased toxicity, especially during the early period after transplantation. Among 45 consecutive patients receiving an allograft for CML, 13 patients were diagnosed to have molecular relapse (MRel), as defined by real-time quantitative reverse transcriptase-polymerase chain reaction, and another four patients were diagnosed to have cytogenetic relapse (CRel) within 6 months. Patients with MRel were randomly assigned to either a 'no therapy' group (group A, n=6), in which immunotherapy was reserved until CRel, or an 'immunotherapy' group (group B, n=7). In group A, all MRel progressed to CRel, and molecular remission (MR) was achieved in four (67%) after immunotherapy. The remaining two patients died of extensive GVHD and fungal pneumonia. In group B, only two MRel progressed to CRel and the remaining five (71%) achieved MR. Two patients died in the absence or loss of response. In patients relapsing directly into CRel (n=4), immunotherapy induced MR in two patients (50%). Earlier intervention played a role in preventing disease progression but this effect was not translated into better survival, which could have been overcome by imatinib mesylate, which induced MR and cytogenetic remission in nonresponders without toxicity.