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BACKGROUND: Acute lymphoblastic leukemia (ALL) is the most common of all pediatric cancers. Aside from predisposing to ALL, polymorphisms could also be associated with poor outcome. Indeed, genetic variations involved in drug metabolism could, at least partially, be responsible for heterogeneous responses to standardized leukemia treatments, hence requiring more personalized therapy. AIMS: (a) to determine the prevalence of seven common genetic polymorphisms including those that affect the folate and/or thiopurine metabolic pathways, i.e., cyclin D1 (CCND1-G870A), ɣ-glutamyl hydrolase (GGH-C452T), methylenetetrahydrofolate reductase (MTHFR-C677T and MTHFR-A1298C), thymidylate synthase promoter (TYMS-TSER), thiopurine methyltransferase (TPMT*3A and TPMT*3C) and inosine triphosphate pyrophosphatase (ITPA-C94A), in Caucasian (N=94, age< 20) and Vietnamese (N=141, age< 16) childhood ALL; (b) to assess the impact of a multilocus genetic risk score (MGRS) on relapse-free survival (RFS) using a cox proportional-hazards regression model. RESULTS: The prevalence of MTHFR-677TT genotype was significantly higher in Caucasian (p = 0.008), in contrast to the prevalence of TYMS-TSER*3R/3R and ITPA-94AA/AC genotypes which were significantly higher in Vietnamese (p < 0.001 and p = 0.02, respectively). Compared to children with a low MGRS (≤3), those with a high MGRS (≥4) were 2.06 (95% CI = 1.01 - 4.22; p = 0.04) times more likely to relapse. Adding MGRS into a multivariate Cox regression model with race/ethnicity and four clinical variables improved the predictive accuracy of the model (AUC from 0.682 to 0.709 at 24 months). CONCLUSION: Including MGRS into a clinical model improved the predictive accuracy of short and medium-term prognosis, hence confirming the association between well determined pharmacogenotypes and outcome of pediatric ALL. Whether variants on other genes associated with folate metabolism can substantially improve the predictive value of current MGRS is not known but deserves further evaluation.

BACKGROUND: Genome-wide association studies have identified single nucleotide polymorphisms (SNPs) associated with higher risk of prostate cancer (PCa). This study aimed to evaluate whether published SNPs improve the performance of a clinical risk-calculator in predicting prostate biopsy result. METHODS: Three hundred forty-six patients with a previous prostate biopsy (191 positive, 155 negative) were enrolled. After literature search, nine SNPs were selected for their statistically significant association with increased PCa risk. Allelic odds ratios were computed and a new logistic regression model was built integrating the clinical risk score (i.e., prior biopsy results, PSA level, prostate volume, transrectal ultrasound, and digital rectal examination) and a multilocus genetic risk score (MGRS). Areas under the receiver operating characteristic (ROC) curves (AUC) of the clinical score alone versus the integrated clinic-genetic model were compared. The added value of the MGRS was assessed using the Integrated Discrimination Improvement (IDI) and Net Reclassification Improvement (NRI) statistics. RESULTS: Predictive performance of the integrated clinico-genetic model (AUC = 0.781) was slightly higher than predictive performance of the clinical score alone (AUC = 0.770). The prediction of PCa was significantly improved with an IDI of 0.015 (P-value = 0.035) and a continuous NRI of 0.403 (P-value

Risk factors for Buruli ulcer (BU) are poorly understood. We conducted a case-control study in southern Benin to investigate the association between haemoglobin variants S or C and BU, and particularly the association between haemoglobinopathies HbSS/SC and BU osteomyelitis. We compared the haemoglobin genotype of 179 patients with BU and 44 with BU osteomyelitis to that of 242 community controls. We found no evidence of an increased risk of BU according to the presence of haemoglobin variants S and/or C [odds ratio adjusted for sex, age, region of residence and ethnicity: 1.24 (95% CI: 0.80-1.93), P = 0.34]. Haemoglobin variants S and C are unlikely to play a role in the BU burden. However, haemoglobinopathies HbSS/SC were more frequent among BU osteomyelitis patients than among controls (6.8% vs. 1.0%, Fisher's exact P-value = 0.045), which may suggest that those disorders facilitate growth of Mycobacterium ulcerans in the bone matrix.

OBJECTIVE: Individuals with Type 2 diabetes are at increased risk of stroke. Plasma homocysteine (tHcy) is an independent risk factor for cardiovascular (CV) disease. The methylene-tetrahydrofolate reductase (MTHFR) gene polymorphism (thermolabile variant C(677)T) is associated with CV risk, partly as a result of increased Hcy, especially in homozygous subjects. AIM: To relate the occurrence of the MTHFR polymorphism with stroke prevalence by examining allelic frequency and genotype distribution in 165 subjects with Type 2 diabetes studied for the presence of thermolabile C(677)T MTHFR mutation. RESULTS: Mean age was 67.7 years, and tHcy 18.2 micromol/l. T allele frequency was 38.5%. MTHFR genotypes were: normal (CC) 40%; heterozygous (CT) 43%; homozygous (TT) 17%. Serum levels of folic acid and B12 vitamin were within normal limits. Stroke prevalence was 14%. Sixty-four per cent of stroke-free subjects had the normal C allele vs. 46% in stroke subjects. The frequencies of genotypes (CC-CT-TT) were (%): 44-41-15 in stroke-free vs. 17-57-26 in stroke patients. Coronary (CAD) and peripheral artery disease (PAD) were common in all groups, with no differences according to genotypes. Stroke prevalence was markedly higher in genotypes CT and TT (18 and 21%) compared with CC (6%). Mean tHcy levels were higher in TT subjects. CONCLUSION: The allelic frequency of C(677)T MTHFR mutation in Type 2 diabetes subjects with stroke is markedly different from that of subjects without stroke. Genotypic characteristics suggest that C(677)T MTHFR mutation confers a higher risk for stroke to both homozygous and heterozygous T allele carriers that cannot be ascribed solely to raised tHcy and/or lower folate status in CT subjects, nor to phenotypic expression of conventional risk factors for stroke. The impact of the MTHFR polymorphism on stroke may result from T allele-linked deleterious effects, or C allele-linked protection. Confirmatory studies are warranted, as this cohort was not randomly selected, and a type 1 error cannot be ruled out.

OBJECTIVE: Blood cultures and cultures of disc material are required to identify and treat bacterial agents responsible for septic spondylodiscitis, but these methods have limited sensitivities. We undertook this study to compare nonculture amplification-based DNA analysis with conventional culture of disc aspirate. METHODS: Nineteen patients with spondylodiscitis, including 11 with a history of spinal surgery, presented with negative blood cultures and underwent percutaneous disc or epidural abscess puncture for bacterial diagnosis. Amplification by polymerase chain reaction was performed on 16S ribosomal DNA universal target genes and femA staphylococci-specific target genes in all patients, and on the upstream p34 mycobacterial gene in 1 patient. Species identification relied on amplicon sequencing and comparison with templates from GenBank. Amplification of the femA gene led to subsequent testing for methicillin resistance by amplification of the mecA gene. Further assessment using a staphylococci- and methicillin resistance-specific DNA array was performed on 3 samples. RESULTS: Microbiologic and molecular assays identified the causative organism in 14 of 19 patients (74%) and 19 of 19 patients (100%), respectively. In culture-positive patients, DNA-based and microbiologic results were highly correlated. Five agents (Staphylococcus simulans, Staphylococcus sciuri, Brucella species, Actinomyces israelii, and Mycobacterium tuberculosis complex) were identified only by DNA-based methods. In 1 sample, Corynebacterium jeikeium and coagulase-negative Staphylococcus were both cultured, whereas DNA analysis identified only Staphylococcus hominis. CONCLUSION: DNA-based methods are highly sensitive and specific. They can usefully complement standard microbiologic methods for identifying the cause of infectious spondylodiscitis and contribute to species-specific therapeutic orientation in patients with negative blood and disc aspirate cultures.

AIMS: To investigate the distribution of cytochrome P450 2C9 (CYP2C9) and 2C19 (CYP2C19) genotype frequencies in the Beninese and Belgian Caucasian populations. METHODS: Beninese (n = 111) and Belgian (n = 121) were genotyped for CYP2C9*2, *3, *4, *5, and *11 as well as for CYP2C19*2 and*3. RESULTS: The distribution of alleles was: CYP2C9*1: 95.5 vs. 82.2% (P < 0.001); CYP2C9*2: 0 vs. 10% (P < 0.001); CYP2C9*3: 0 vs. 7.4% (P < 0.01); CYP2C9*4: both 0%; CYP2C9*5: 1.8 vs. 0% (P = 0.05); and CYP2C9*11: 2.7 vs. 0.4% (P < 0.05). The frequencies of the CYP2C19*2 allele were 13 vs. 9.1%, respectively. CYP2C19*3 was not detected in either population. The 95% confidence intervals for the differences of frequencies of CYP2C9*1, CYP2C9*2, CYP2C9*3, CYP2C9*4, CYP2C9*5, CYP2C9*11, CYP2C19*1, CYP2C19*2 and CYP2C19*3 between Belgian and Beninese were 7%, 19%; - 14%, - 6%; - 11%, - 4%; - 1%, 1%; 0%, 4%; 0%, 5%; - 10%, 2%; - 2%, 10%; - 1%; respectively. The distributions of CYP2C9 genotypes in the Beninese and Belgian individuals were: CYP2C9*1/*1: 91 vs. 67% (P < 0.00001); CYP2C9*1/*2: 0 vs. 18.2% (P < 0.0001); CYP2C9*1/*3: 0 vs. 11.6% (P < 0.001); CYP2C9*1/*5: 3.6 vs. 0% (P = 0.05); CYP2C9*1/*11: 5.4 vs. 0.8% (P = 0.05); CYP2C9*2/*3: 0 vs. 1.6% (NS); CYP2C9*3/*3: 0 vs. 0.8% (NS). The distributions of CYP2C19 genotypes between these ethnic groups were: CYP2C19*1/*1: 73.9 vs. 83.5% (NS); CYP2C19*1/*2: 26.1 vs. 14.9% (P < 0.05); CYP2C9*2/*2: 0 vs. 1.6% (NS). CONCLUSIONS: Differences of allele frequencies between Beninese and Belgian populations were statistically significant for CYP2C9*2, *3, *5 and *11, but not for CYP2C9*4 or for CYP2C19*2 and *3.

BACKGROUND: To predict poor outcome in patients with a biochemical recurrence (rising PSA) after radical prostatectomy (RP), urologists rely primarily on Gleason score, PSA doubling time, and time from surgery to biochemical (i.e., PSA) recurrence. In the present study, we assess the value of RT-PCR detection circulating prostate cells in blood of patients with a rising PSA. METHODS: RNA from blood samples was obtained from 55 patients with a rising PSA and from 45 patients without evidence of biochemical failure (PSA < 0.1 ng/ml). Both groups were matched for age, Gleason score, pT stage, and interval between radical prostatectomy and PCR testing. RESULTS: PSA positive cells were detected in 1/45 (2%) patients without a PSA recurrence and 19/55 (34%) patients with a PSA recurrence. In the rising PSA group, mean PSA doubling time was significantly shorter in patients with positive RT-PCR (5 months) than in patients with negative RT-PCR (16 months; P = 0.001). An earlier onset of recurrence was also detected in patients with a positive RT-PCR (31 months for positive RT-PCR vs. 50 months for negative RT-PCR) but this result did not achieve statistical significance (P = 0.102). Salvage radiation therapy was administered in 15 patients. Three of the five patients with a positive RT-PCR progressed during radiotherapy whereas 7 of the 10 patients with a negative RT-PCR obtained a complete response and none have progressed. CONCLUSIONS: These preliminary results suggest that RT-PCR detection of prostate cells in blood of patients after RP correlates with rapidly progressing biochemical failure after RP.

Cytochrome P-450 3A enzymes belong to the most abundant subfamily of the cytochrome P-450 system. They are predominantly found in the liver where they metabolize numerous drugs and endogenous substances such as oestrogens. However, they are also expressed by normal and tumoural extrahepatic tissues. Accordingly, immunolocalization was assessed in malignant breast tumours (n=32) and normal counterparts, by using a monoclonal antibody that recognizes all human CYP3A proteins. We investigated a potential relation between expression of CYP3A protein expression, the degree of tumour differentiation assessed by the histological grade and the proliferation index assessed by Ki-67 immunostaining. Immunodetection of CYP3A was observed in 27 of the 32 tumours analyzed (84%). A focal staining was also observed in the adjacent normal breast tissue in 33% of the samples, but expression was always fainter than in tumours. A significant negative association was found between CYP3A and the proliferation index, but there was no relation with receptor status or tumour differentiation. While CYP3A protein expression can be found in normal breast tissues, these data highlight higher and more frequent CYP3A in malignant breast cells. Such expression in malignant breast cells appears inversely related to the proliferation index whereas no relation is found with tumour differentiation.

Androgen ablation has been the standard treatment of symptomatic patients with metastatic prostate cancer for more than 50 years. Within the last 15 years, the introduction of prostate-specific antigen (PSA) has induced a stage migration toward less extensive disease and a dramatic decrease in the proportion of men presenting with N+/M+ disease. Historical studies, conducted during the pre-PSA era, are therefore of limited interest in counseling modern patients. The routine use of radical therapies such as radical prostatectomy and radiotherapy has considerably expanded the problem of timing of endocrine treatment in range and complexity. Advanced disease is now diagnosed in patients with limited involvement of extraprostatic sites and even in patients presenting an isolated elevation of PSA after radical treatment. In the absence of clear guidelines, data from past literature and ongoing modern studies were compiled in the present review in an attempt to generate practical considerations.

We report an infant with normal neurological development and phenotype who developed bilateral retinoblastoma (RB). This patient, despite lack of dysmorphic features, demonstrated constitutional abnormality of the long arm of chromosome 13 on standard karyotype. We recommend systematic cytogenetic examinations complemented by fluorescent in situ hybridization as second-line screening in all patients suspected for hereditary RB despite negative RB1 molecular screening and normal phenotype.