Juliane Bentes Picanço

TNF -308G > A promoter polymorphism (rs1800629) and outcome from critical illness

BACKGROUND The susceptibility to adverse outcome from critical illness (occurrence of sepsis, septic shock, organ dysfunction/failure, and mortality) varies dramatically due to different degrees of inflammatory response. An over expression of tumor necrosis factor alpha (TNF-α) can lead to the progression of the inflammatory condition. OBJECTIVE We assessed the relationship of the genotype distribution of -308G >A TNF-α polymorphism with regard to the development of sepsis, septic shock, higher organ dysfunction or mortality in critically ill patients. METHODS Observational, hospital-based cohort study of 520 critically ill Caucasian patients from southern Brazil admitted to the general ICU of São Lucas Hospital, Porto Alegre, Brazil. Patients were monitored daily from the ICU admission day to hospital discharge or death, measuring SOFA score, sepsis, and septic shock occurrences. The -308G >A TNF-α SNP effect was analyzed in the entire patient group, in patients with sepsis (349/520), and in those who developed septic shock (248/520). RESULTS The genotypic and allelic frequencies were -308GG = 0.72; -308GA = 0.27; -308AA = 0.01; -308G = 0.85; -308A = 0.15. No associations were found with sepsis, septic shock, organ dysfunction, and/or mortality rates among the TNF-α genotypes. Our results reveal that the -308G >A TNF-α SNP alone was not predictive of severe outcomes in critically ill patients. CONCLUSION The principal novel input of this study was the larger sample size in an investigation with -308G > A TNF-α SNP. The presence of -308A allele is not associated with sepsis, septic shock, higher organ dysfunction or mortality in critically ill patients.

Higher frequency of septic shock in septic patients with the 47C allele (rs4880) of the SOD2 gene

AIM To analyze the effect of the two different versions of the manganese superoxide dismutase gene (SOD2) on sepsis. The SOD2 gene presents the 47C>T single nucleotide polymorphism (SNP; ID: rs4880) which produces MnSOD with different activities. The -9Val MnSOD (47T allele) is less efficient than the -9Ala version (47C allele). During sepsis there are abundance of ROS, high SOD2 expression and excess of H(2)O(2) synthesis. High concentrations of H(2)O(2) could affect the sepsis scenario and/or the sepsis outcome. METHODS We determined the 47C>T single nucleotide polymorphism (SNP) frequencies in 529 critically ill patients with or without sepsis, facing outcome. To collect information on population frequencies, we obtained a pilot 47C>T genotypic and allelic frequencies in a random group of 139 healthy subjects. RESULTS We compared the 47C allele carriers (47CC+47CT genotypes) with 47TT homozygotes and noticed a significant association between 47C allele carriers and septic shock in septic patients (P=0.025). With an adjusted binary multivariate logistic regression, incorporating 47C>T SNP and the main clinical predictors, we showed high SOFA scores [P<0.001, OR=9.107 (95% CI=5.319-15.592)] and 47C allele [P=0.011, OR=2.125 (95% CI=1.190-3.794)] were significantly associated with septic shock outcome. With this information we presented a hypothesis suggesting that this negative outcome from sepsis is possibly explained by effects on cellular stress caused by 47C allele. CONCLUSION In our population there was a significant higher frequency of septic shock in septic patients with the 47C allele of the SOD2 gene. This higher 47C allele frequency in septic patients with negative outcome could be explained by effects of higher activity MnSOD on cellular stress during the sepsis.

Very Low Frequencies of Toll-Like Receptor 2 Supposed-2029T and 2258A (RS5743708) Mutant Alleles in Southern Brazilian Critically Ill Patients: Would It Be a Lack of Worldwide-Accepted Clinical Applications of Toll-Like Receptor 2 Variants?

Toll-like receptor 2 (TLR2) is a recognition receptor for the widest repertoire of pathogen-associated molecular patterns. Two polymorphisms of TLR2 could be linked to reduced nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) activation and to increased risk of infection (supposed-2029C>T and 2258G>A). We investigated the supposed-2029C>T and 2258G>A TLR2 polymorphisms in 422 critically ill patients of European origin from southern Brazil (295 with sepsis and 127 without sepsis) and reviewed 33 studies on these polymorphisms, conducting a quality assessment with a score system. Among our patients we found only one heterozygote (1/422) for the supposed-2029C>T and none for the 2258G>A (0/422) single nucleotide polymorphism (SNP). We were unable to find a clinical application of supposed-2029T and 2258A allele analyses in our southern Brazilian population. Our review detected that current TLR2 SNP assays had very controversial and contradictory results derived from reports with a variety of investigation quality criteria. We suggest that, if analyzed alone, the supposed-2029C>T and 2258G>A TLR2 SNP are not good candidates for genetic markers in studies that search for direct or indirect clinical applications between genotype and phenotype. Future efforts to improve the knowledge and to provide other simultaneous genetic markers might reveal a more effective TLR2 effect on the susceptibility to infectious diseases.

Tri-allelic pattern at the TPOX locus: a familial study.

Alleles at the TPOX STR locus have 6-14 different numbers of a four-nucleotide (AATG) repeat motif arranged in tandem. Although tri-allelic genotypes are generally rare, the TPOX tri-allelic pattern has a higher frequency, varying widely among populations. Despite this, there are few accurate reports to disclose the nature of the TPOX third allele. In this work we present data obtained from 45 individuals belonging to the same pedigree, in which there are cases of tri-allelic TPOX genotypes. The subjects were apparently healthy with a normal biological development. We noticed six tri-allelic cases in this family, and all of them were women. Karyotype analysis showed no occurrence of partial 2p trisomy. All the tri-allelic cases had the genotype 8-10-11, probably due to three copies of the TPOX STR sequence in all cells (Type 2 tri-allelic pattern). Based on previous data we assumed the allele 10 as the TPOX third allele. The pedigree analyses show evidences that the TPOX extra-allele was the allele10, it is placed far from the main TPOX locus, and that there is a potential linkage of the TPOX extra-allele-10 with Xq. This was the first study that included a large pedigree analysis in order to understand the nature TPOX tri-allelic pattern.

Procedures to recover DNA from pre-molar and molar teeth of decomposed cadavers with different post-mortem intervals

A task-force to resolve 26 pending forensic caseworks was carried out. We tested four different protocols to extract DNA from molar and pre-molar teeth from 26 cadavers with post-mortem intervals from 2 months to 12 years. We compared the amount of DNA and DNA profiles with the time elapsed between death and laboratory procedures. Molar or pre-molar teeth were removed from the corpses, cleaned, and DNA was extracted using 2 or 12h of incubation on lysis buffer and filtered using concentration column or precipitated with isopropanol. DNA profiles were obtained using PowerPlex16™ System PCR Amplification Kit, AmpFlSTR(®) Yfiler™ and/or mtDNA sequencing. Complete DNA profiles comparison and statistical evaluation allowed unambiguous identification of the 26 victims. No significant differences were observed in the amount of DNA obtained with the distinct incubation times. The use of concentration column resulted in an increased amount of DNA when compared to isopropanol. However, the lower concentration of DNA obtained with isopropanol seemed to have been compensated by the higher purity. No significant differences in the number of amplified loci were found. A non-significant tendency was found between the amount of total DNA recovered and the time elapsed between death and laboratory procedures. The increase of post-mortem time did not interfere in the analysed autosomal loci. In conclusion, molar and pre-molar teeth were shown to be good candidates to obtain satisfactory DNA profiles, suggesting the high potential of tooth samples as source for DNA typing independently of the decomposed corpses time or laboratory procedures.

Neutrality of miniSTR D22S1045 marker by Ewing's sarcoma phenotype.

Neutrality investigations of markers with forensic use are important to see if a phenotypic trait is being expressed in relation to the alleles of the marker. MiniSTR marker D22S1045 (locus 22q12.3) is localized near the breakpoint region of the EWS gene (22q12.2), which leads to the development of Ewings Sarcoma. Analyzing allele frequencies and linkage disequilibrium in Ewings sarcoma patients and non-affected populations, we found that the marker mD22S1045 was neutral when related to Ewings Sarcoma.