Detection of bacterial contamination in platelet concentrates from Brazilian donors by molecular amplification of the ribosomal 16S gene.

OBJECTIVE: The aim of our work was to establish a semi-automated high-throughput DNA amplification method for the universal screening of bacteria in platelet concentrates (PCs). BACKGROUND: Among cases of transfusion transmission of infectious agents, bacterial contamination ranks first in the number of events, morbidity and mortality. Transmission occurs mainly by transfused PCs. Automated culture is adopted by some blood banks for screening of bacterial contamination, but this procedure is expensive and has a relatively long turnaround time. METHODS: PCs were spiked with suspensions of five different bacterial species in a final concentration of 1 and 10 colony-forming units (CFU) per millilitre. After incubation, the presence of bacteria was investigated by real-time polymerase chain reaction (PCR) and by the Enhanced Bacterial Detection System (eBDS, Pall) assay as a reference method. Real-time PCR amplification was performed with a set of universal primers and probes targeting the 16S rRNA gene. Co-amplification of human mitochondrial DNA served as an internal control. RESULTS: Using the real-time PCR method, it was possible to detect the presence of all bacterial species tested with an initial concentration of 10 CFU mL-1 24 h after contamination, except for Staphylococcus hominis. The PCR assay also detected, at 24 h, the presence of Serratia marcescens and Enterobacter cloacae with an initial concentration of 1 CFU mL-1 . CONCLUSIONS: The real-time PCR assay may be a reliable alternative to conventional culture methods in the screening of bacterial contamination of PCs, enabling bacterial detection even with a low initial concentration of microorganisms.

-318C/T polymorphism of the CTLA-4 gene is an independent risk factor for RBC alloimmunization among sickle cell disease patients.

Cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) molecule is expressed on T-lymphocyte membrane and negatively influences the antigen-presenting process. Reduced expression of CTLA-4 due to gene polymorphisms is associated with increased risk of autoimmune disorders, whose physiopathology is similar to that of post-transfusion red blood cell (RBC) alloimmunization. Our goal was to evaluate if polymorphisms of CTLA-4 gene that affect protein expression are associated with RBC alloimmunization. This was a case-control study in which 134 sickle cell disease (SCD) patients and 253 non-SCD patients were included. All patients were genotyped for the polymorphisms 49A/G and -318C/T of CTLA-4 gene. The genotype frequency of -318C/T differed significantly between alloimmunized and nonalloimmunized SCD patients, irrespective of clinical confounders (p = .016). SCD patients heterozygous for -318T allele presented higher risk of alloantibody development (OR: 5.4, CI: 1.15-25.6). In conclusion, the polymorphism -318C/T of CTLA-4 gene is associated with RBC alloimmunization among SCD patients. This highlights the role played by CTLA-4 on post-transfusion alloantibody development.

Contrasting HCV and HIV seroepidemiology in 11 years of blood donors screening in Brazil.

BACKGROUND: Blood donors are, in principle, healthy individuals who may be revealed as infectious for blood-borne agents by the laboratory screening process, depicting the asymptomatic burden of the disease. Therefore, monitoring hepatitis C virus (HCV)-infected donor and human immunodeficiency virus (HIV)-infected donor and associating to their demographical and behavioural characteristics may shed light on the dynamics and contemporary changes in these viruses' epidemiology. METHODS: Donors presenting repeatedly reactive HCV or HIV serology/nucleic acid testing (NAT) screening results were submitted to confirmatory testing. Confirmed positive donors were invited to return to the blood bank for notification and counselling when a follow-up sample was obtained and an interview performed to eventually disclose potential risks. HCV- or HIV-infected donors identified over 11 years of screening (2004-2015) were evaluated for demographic and behavioural parameters. RESULTS: In the period, 139 160 donations were screened, and 36 (0.025%) were found positive for HIV, stemming from 29 male and 7 female donors. Among those, eight subjects were repeat donors. A total of 95 donations were found repeatedly reactive for HCV (0.068%), obtained from 60 men and 35 women. Noticeably, in despite of a higher HCV prevalence in the donor population, the incidence of HIV among repeat donors was 10 times that of HCV (18 × 1.6/100 000 persons-year, respectively). On average, HIV-seroreactive men were found to be younger (mean = 34 years old) than women (mean = 40 years old). A total of 10 donors acknowledged sexual behaviours not previously informed, including 2 who were aware of their HIV-positive status and another 2 who admitted to be seeking HIV testing. No window period donation was verified. DISCUSSION: The majority of the HIV-infected donors are young males who deny risk factors in the interview and also ignore the confidence self-exclusion opportunity. As they may reiterate this behaviour in serial donations, use of the most sensitive laboratory testing is justified in this setting.

Screening for the SMIM1*64_80 del Allele in blood donors in a population from Southern Brazil.

BACKGROUND AND OBJECTIVES: Serological screening for the Vel- phenotype is complex given the large individual variation in the levels of expression of the Vel antigen, and the polyclonal anti-human sera of immunised persons, when available, show heterogeneous reactivity levels. Studies of the SMIM1 gene have enabled the development of several molecular methodologies that will be crucially important for the screening of different populations, including Brazilians. To evaluate the deletion of 17 bp in the SMIM1 gene in a population from the south of Brazil, 448 unrelated blood donors from 7 regions comprising the haemotherapy network in the state of Santa Catarina were evaluated between August 2011 and March 2014. MATERIALS AND METHODS: DNA samples from these donors were analysed employing a 5' nuclease real-time polymerase chain reaction (PCR) assay targeting the 17 bp deletion in the SMIM1 gene. RESULTS: Among the 448 samples analysed, 10 (2·23%) harboured the 17 bp deletion of the gene SMIM1, and all were heterozygote for the SMIM1*64_80 del allele. CONCLUSION: The allelic frequency found differed from those observed in other Caucasian populations. This difference can be explained by the ethnic make-up of each Caucasian population. The data obtained are important to characterise the correct phenotype of the donor as the serological assay results are not reliable due to variations in the expression intensity of the Vel antigen in heterozygote donors for the SMIM1*64_80 del allele. Moreover, the tool used in this study is of great value for identifying a donor Vel- phenotype and supplying a possible need for transfusion.

HPV genotyping and p16 expression in Xingu Indigenous Park, Brazil.

The association between high-risk human papillomavirus (HPV) genotypes and p16 expression in indigenous women from the Xingu Indigenous Park, Brazil, was unknown. This study evaluated p16 expression in women with a histological diagnosis of cervical intraepithelial neoplasia (CIN) 3 or higher and correlated this expression with HPV genotypes to determine possible discrepancies in the expression of this marker. We evaluated 37 previously collected samples with different HPV genotypes and high-grade lesions diagnosed based on cytology, histology, and colposcopy. Immunohistochemical analysis was performed using paraffin-embedded tissue sections and the CINtec® Histology Kit. p16 protein expression was investigated by immunostaining with an anti-p16 antibody. HPV genotyping was performed by reverse hybridization. The age of the study population ranged from 22-75 years (43.81 ± 15.89 years) and parity ranged from 1-11 (5.92 ± 2.58). Thirteen different HPV genotypes were found using the INNO-LiPA kit. Single and multiple infections by HPV were found with prevalence of single infections (P = 0.029). Comparison between HPV genotype and simple or multiple infections was highly significant; it was observed more HPV 52 followed by HPV 16 in single infections (P < 0.001). p16 expression was predominantly diffuse, which was observed in 91.7% of lesions, whereas 8.3% were focal (P < 0.001). HPV 52, HPV 16 and 31 were the most prevalent HPV types in high-grade CIN in these indigenous women. Diffuse p16 expression in high-grade CIN was not influenced by the viral genotype; however, more studies are necessary to further our understanding of this restricted group.

HPV infection-associated anogenital cyto-colpo-histological findings and molecular typing in HIV-positive women.

HIV and human papillomavirus (HPV) coinfection is increasing, especially in the anal canal (AC) and cervico-vaginal regions. We identified anal epithelium abnormalities related to high-risk HPV (HR-HPV) lesions in the lower genital tracts (LGTs) of HIV-positive women, described the HPV genotypes identified, and assessed the expression of E6/E7 oncogenes in coinfected patients. Ninety-eight women were enrolled in groups combining HIV status and presence or absence of HPV in the LGT. Anal and cervical smears were collected for cytology and HR-HPV assays using Cobas(®) and/or PapilloCheck(®). Samples with highly oncogenic HPV genotypes were confirmed by NucliSENS EasyQ(®). Forty-two HIV-positive (25-52; mean age 39.5) and 56 HIV-negative (18-58; mean age 35.7) patients were included. E2 and C1 groups presented AC alterations (P = 0.002); altered images for high-resolution anoscopy were higher in E1 and C2 (P < 0.001). Of the 29 women with alterations, 41.38% were HIV-negative and 58.62% were HIV-positive (P < 0.001). HIV-positive patients accounted for 29% of the anal high-grade squamous intraepithelial lesions (P = 0.015). The Cobas(®) positive result frequency was higher in three AC groups than in the other groups. There was variation in the number of HPV types in the cervico-vaginal samples among the study groups (P < 0.001). Anal cytology and anoscopy showed more altered findings in HIV-positive patients with HPV in the LGT. HR-HPV anal infections by various genotypes are common and are associated with cervical infections in HIV-positive patients. E6/E7 expression is apparently more common in the AC of HIV-positive women.

Absence of nonprimate hepacivirus-related genomes in blood donors seroreactive for hepatitis C virus displaying indeterminate blot patterns.

Despite intensive search, no primate homologue to the Hepatitis C Virus (HCV) has ever been found. The search for a zoonotic origin for HCV has been renewed recently when a virus, now known as non-primate hepacivirus (NPHV), with a high homology to HCV was found in dogs. A variable proportion of anti-HCV reactive blood donors submitted to the immunoblot (IB) to confirm their HCV status, present indeterminate results. The degree of homology between HCV and NPHV suggests that humans may be infected by NPHV or NPHV-like viruses. Maximum similarity between NHPV and HCV is observed in the nonstructural regions 3 and 5. Peptides representing both domains are present in IB assays, so it is reasonable to suppose that blood donors harboring such viruses may display cross-reactivity to the HCV antigenic fractions. Fifty-nine plasma samples from blood donors found reactive for anti-HCV and presenting IB indeterminate results were submitted to five distinct PCR reactions under low-stringency conditions, employing primers targeting GBV-C 5'UTR and NS3, Flavivirus-genus NS5 and NPHV 5'UTR and NS3. No amplification was obtained with all primer pairs tested except for five samples that amplified both 5'UTR and NS3 fragments from GBV-C. Unbiased next-generation sequencing may prove or rule out the existence of HCV-related viruses in IB indeterminate samples.

Prevalence of Treponema pallidum DNA among blood donors with two different serologic tests profiles for syphilis in São Paulo, Brazil.

The presence of Treponema pallidum DNA was assessed by real-time PCR in samples of blood donors with reactive serologic tests for syphilis. Treponema pallidum DNA was detected in two (1·02%) of 197 samples of VDRL>8, EIA+ and FTA-ABS+ donors, and in no sample from 80 VDRL−, EIA+ and FTA-ABS+ donors. Donors VDRL−, EIA+ and FTA-ABS+ lack demonstrable T. pallidum DNA in their blood and are unlike to transmit syphilis. Donors VDRL>8, EIA+ and FTA-ABS+ carry the risk of syphilis infectivity even in concomitance to antibodies detection. Serologic screening for syphilis may still play a role to prevent its transfusion transmission.

Occult hepatitis B virus infection among blood donors from the Brazilian Amazon: implications for transfusion policy.

BACKGROUND: Brazil requires the performance of both a test for hepatitis B surface antigen (HBsAg) and a test for antibodies to the core of hepatitis B for blood donor screening. Blood centres in regions of high HBV endemicity struggle to maintain adequate stocks in face of the high discard rates due to anti-HBc reactivity. We evaluated the potential infectivity of donations positive for anti-HBc in search of a rational approach for the handling of these collections. STUDY DESIGN AND METHODS: We tested anti-HBc reactive blood donations from the state of Amazonas for the presence of HBV DNA and for titres of anti-HBs. The study population consists of village-based donors from the interior of Amazonas state. RESULTS: Among 3600 donations, 799 were anti-HBc reactive (22·2%). We were able to perform real-time PCR for the HBV S gene on specimens from 291 of these donors. Eight of these samples were negative for HBsAg and positive for HBV DNA and were defined as occult B virus infections (2·7%). Six of those eight specimens had anti-HBs titres above 100 mIU/ml, indicating the concomitant presence of the virus with high antibody titres. CONCLUSION: A small proportion of anti-HBc reactive donors carry HBV DNA and anti-HBs testing is not useful for predicting viremia on them. This finding indicates the possibility of HBV transmission from asymptomatic donors, especially in areas of high HBV prevalence. Sensitive HBV DNA nucleic acid testing may provide another level of safety, allowing eventual use of anti-HBc reactive units in critical situations.

Demographic, risk factors and motivations among blood donors with reactive serologic tests for syphilis in São Paulo, Brazil.

OBJECTIVE: To identify the demographic characteristics, risk factors and motivations for donating among blood donors with reactive serologic tests for syphilis. BACKGROUND: Post-donation interviews with syphilis seropositive blood donors improve recruitment and screening strategies. METHODS: This case-control study compares 75 Venereal Disease Research Laboratory (VDRL) > 8, EIA+ (enzyme immunoassay) and FTA-ABS+ (fluorescent treponemal antibody); 80 VDRL-, EIA+ and FTA-ABS+; and 34 VDRL- and EIA- donors between 2004 and 2009. Donors were assessed by their demographic characteristics, sexual behaviour, history of alcohol and illicit drugs use, and motivations to donate. RESULTS: Donors with VDRL > 8 were more likely to be divorced [AOR = 12·53; 95% confidence interval (CI) 1·30-120·81], to have had more than six sexual partners (AOR=7·1; 95% CI 1·12-44·62) and to report male-male-sex in the past 12 months (AOR=8·18; 95% CI 1·78-37·60). Donors with VDRL-, EIA+ and FTA-ABS+ were less likely to be female (AOR=0·26; 95% CI 0·07-0·96), more likely to be older (AOR=10·2; 95% CI 2·45-42·58 ≥ 39 and <60 years old) and to have had more than six sexual partners in the past 12 months (AOR = 8·37; 95% CI 1·49-46·91). There was no significant difference among groups regarding illicit drugs use; 30·7% (VDRL > 8) and 12·5% (VDRL-, EIA+ and FTA-ABS+) of donors reported that they had been at risk for HIV infection (P = 0·004). One-third of donors came to the blood bank to help a friend or a relative who needed blood. CONCLUSION: Although donors exposed to syphilis reported and recognised some high risk behaviour, most were motivated by direct appeal to donate blood. Monitoring the risk profile of blood donors can benefit public health and improve blood safety.

TP53 and EGFR mutations in combination with lifestyle risk factors in tumours of the upper aerodigestive tract from South America.

Cancers of the upper aerodigestive tract [(UADT): oral cavity, pharynx, larynx and oesophagus] have high incidence rates in some parts of South America. Alterations in the TP53 gene are common in these cancers. In our study, we have estimated the prevalence and patterns of TP53 mutations (exons 4-10) in 236 UADT tumours from South America in relation to lifestyle risk factors, such as tobacco smoking and alcohol drinking. Moreover, we have conducted a pilot study of EGFR mutations (exons 18-21) in 45 tumours from the same population. TP53 mutation prevalence was high: 59% of tumours were found to carry mutant TP53. We found an association between TP53 mutations and tobacco smoking and alcohol drinking. The mutation rate increased from 38% in never-smokers to 66% in current smokers (P-value for trend = 0.09). G:C>T:A transversions were found only in smokers (15%). Alcohol drinkers carried more G:C>A:T transitions (P = 0.08). Non-exposed individuals were more probable to carry G:C>A:T transitions at CpG sites (P = 0.01 for never-smokers and P < 0.001 for never-drinkers). EGFR mutations were found in 4% of cases. Inactivation of TP53 by mutations is a crucial molecular event in the UADT carcinogenesis and it is closely related to exposure to lifestyle risk factors. EGFR mutations do not appear to be a common event in UADT carcinogenesis in this population.

Past, present, and future of COVID-19: a review.

SARS-CoV-2 has recently emerged, becoming a global threat, affecting directly all human beings owing to its morbidity and mortality and indirectly, due to the enormous economic and psychological impact produced by social isolation, the most effective measure so far, but unsustainable for a long period. The scientific effort to understand and control SARS-CoV-2 transmission and clinical impact has been huge, and important achievements are highlighted in this review. Diagnosis is central and is the first step in recognizing and fighting any infectious agent. Instrumental to that is the quality of the data, relying on serological and molecular surveys in addition to trustworthy clinical records. However, the fast spread of a virus adapted for human-to-human respiratory transmission raised a demand for millions of molecular tests that are simply not available. Several candidate drugs are under evaluation in clinical trials. Those with an already recognized safety profile are more auspicious, since, if proven effective, can cut several steps of production and phase 2 and 3 trials. More than one hundred vaccine prototypes are in different stages of development, however, safety and efficacy evaluations cannot be obviated, implicating, most optimistically, in at least months for us to have an effective immunization, the definite measure to allow a safe return to the pre-pandemic lifestyle. Science has never been more necessary and present in daily life. Relying on the best of human wit is the only way out to this pandemic, saving as many lives as possible.

PCR-RFLP assay as an option for primary HPV test.

Persistent human papillomavirus (HPV) infection is an essential factor of cervical cancer. This study evaluated the analytical performance of restriction fragment length polymorphism polymerase chain reaction (PCR-RFLP) assay compared to PapilloCheck® microarray to identify human papilloma virus (HPV) in cervical cells. Three hundred and twenty-five women were analyzed. One sample was used for conventional cytology and another sample was collected using BD SurePath™ kit for HPV tests. Eighty samples (24.6%) were positive for HPV gene by PCR-Multiplex and were then submitted to PCR-RFLP and PapilloCheck® microarray. There was a genotyping agreement in 71.25% (57/80) on at least one HPV type between PCR-RFLP and PapilloCheck® microarray. In 22 samples (27.5%), the results were discordant and those samples were additionally analyzed by DNA sequencing. HPV 16 was the most prevalent HPV type found in both methods, followed by HPVs 53, 68, 18, 39, and 66 using PCR-RFLP analysis, and HPVs 39, 53, 68, 56, 31, and 66 using PapilloCheck® microarray. In the present study, a perfect agreement using Cohen's kappa (κ) was found in HPV 33 and 58 (κ=1), very good for HPV 51, and good for types 16, 18, 53, 59, 66, 68, 70, and 73. PCR-RFLP analysis identified only 25% (20/80) HPV coinfection, and PapilloCheck® microarray found 62.5% (50/80). Our Cohen's kappa results indicate that our in-house HPV genotyping testing (PCR-RFLP analysis) could be applied as a primary HPV test screening, especially in low income countries. If multiple HPV types are found in this primary test, a more descriptive test, such as PapilloCheck® microarray, could be performed.

Past, present, and future of COVID-19: a review

SARS-CoV-2 has recently emerged, becoming a global threat, affecting directly all human beings owing to its morbidity and mortality and indirectly, due to the enormous economic and psychological impact produced by social isolation, the most effective measure so far, but unsustainable for a long period. The scientific effort to understand and control SARS-CoV-2 transmission and clinical impact has been huge, and important achievements are highlighted in this review. Diagnosis is central and is the first step in recognizing and fighting any infectious agent. Instrumental to that is the quality of the data, relying on serological and molecular surveys in addition to trustworthy clinical records. However, the fast spread of a virus adapted for human-to-human respiratory transmission raised a demand for millions of molecular tests that are simply not available. Several candidate drugs are under evaluation in clinical trials. Those with an already recognized safety profile are more auspicious, since, if proven effective, can cut several steps of production and phase 2 and 3 trials. More than one hundred vaccine prototypes are in different stages of development, however, safety and efficacy evaluations cannot be obviated, implicating, most optimistically, in at least months for us to have an effective immunization, the definite measure to allow a safe return to the pre-pandemic lifestyle. Science has never been more necessary and present in daily life. Relying on the best of human wit is the only way out to this pandemic, saving as many lives as possible.

A monoclonal antibody (IID510g52) for the determination of functional domains within integrin cell surface receptors.

Monoclonal antibodies against cell surface receptors can be useful for the study of structural and biochemical features involved in protein interactions underlying platelet adhesion and aggregation. We report here the characterization of a monoclonal antibody, IID510g52 (hereafter referred to as IID5), which has been selected based on its specific binding properties against the platelet membrane glycoprotein IIIa. Characterization of the reactive epitope, including evolutionary conservation and identification of related IID5 target antigens in tumor cells, suggest that the IID5 epitope is implicated in the ligand-binding function of integrin receptors. Indeed, we show that this MoAb acts as a potent inhibitor of platelet aggregation and cell adhesion. Taken together, these results indicate that such a monoclonal may be a strategic tool for better understanding multiple integrin-mediated adhesive reactions, as well as the determination of interacting recognition sites.

Morphologic evidence that disruption of the Golgi apparatus in PFHR 9-tumor cells causes disturbance in the traffic through this organelle.

PFHR 9 is a murine teratocarcinoma-derived tumor which produces basement membrane components. Electron microscopy of the tumor cells disclosed a disorganization of the Golgi complex whose saccules, instead of being flattened, round up into 0.13 micron-wide spherical vesicles (SV). Their shape does not permit the normal stacking of parallel cisternae, and thus these SV become intermingled with transport vesicles (TV) which measure 44 nm in diameter. The cytoplasm of these tumor cells contains numerous multivesicular bodies (MVB) of varying size (ranging from 0.3 to 2.6 micron), which occupy 7% of the cellular volume. These MBV are packed with very many small vesicles similar in all aspects to the TV, and also contain a few larger vesicles which resemble the altered Golgi saccules (SV). Since these MVB display morphologic evidence for gradual lysis of their contents and strongly react with the cytochemical method for acid phosphatase, it is assumed that MVB are autophagic vacuoles which result from the accumulation of TV. This seems to be a unique example of a disease of the Golgi stack, with consequent accumulation and disposal of this material via autophagic vacuoles.

Hepatitis G virus/GB virus C in Brazil. Preliminary report.

Hepatitis G virus/GB virus C is a novel flavivirus recently detected in hepatitis non A-E cases. In this study, the presence of this virus in chronic non-B, non-C hepatitis patients was evaluated using GBV-C specific PCR and this virus was detected in one out of thirteen patients. This patient has presented a severe liver failure, has lived for a long time in the Western Amazon basin and no other cause for this clinical picture was reported. The impact of the discovery of this new agent is still under evaluation throughout the world. The study of the prevalence of this virus among chronic hepatitis patients and healthy individuals (as blood donors) will furnish subside to evaluate its real pathogenicity.

Influence of hepatitis G virus (GB virus C) on the prognosis of HIV-infected women.

This study was undertaken to evaluate the prevalence of GB virus C (GBV-C) viraemia and anti-E2 antibody, and to assess the effect of co-infection with GBV-C and HIV during a 10-year follow-up of a cohort of 248 HIV-infected women. Laboratory variables (mean and median CD4 counts, and HIV and GBV-C viral loads) and clinical parameters were investigated. At baseline, 115 women had past exposure to GBV-C: 57 (23%) were GBV-C RNA positive and 58 (23%) were anti-E2 positive. There was no statistical difference between the groups (GBV-C RNA + /anti-E2 - , GBV-C RNA - /anti-E2 + and GBV-C RNA - /anti-E2 - ) regarding baseline CD4 counts or HIV viral loads (P = 0.360 and 0.713, respectively). Relative risk of death for the GBV-C RNA + /anti-E2 - group was 63% lower than that for the GBV-C RNA - /anti-E2 - group. Multivariate analysis demonstrated that only HIV loads ≥ 100,000 copies/mL and AIDS-defining illness during follow-up were associated with shorter survival after AIDS development. It is likely that antiretroviral therapy (ART) use in our cohort blurred a putative protective effect related to the presence of GBV-C RNA.