Interleukin 17F Gene Polymorphism as a Potential Protective Factor in the Immunopathology of Ocular Toxoplasmosis.

Ocular toxoplasmosis (OT) is characterised by intraocular inflammation due to Toxoplasma gondii infection. Studies have found that interleukin 17 (IL-17) plays a central role in the pathology of OT. However, nucleotide variability in IL17 and interleukin 17 receptor (IL17R) genes has not been characterised in OT. As cytokine gene polymorphisms may influence the expression of these molecules, the aim of this study was to verify whether IL17A (rs2275913), IL17F (rs763780), IL17RA (rs4819554) and IL17RC (rs708567) polymorphisms are associated with OT in a Brazilian population. This study enrolled 214 patients seropositive for T. gondii (110 with OT and 104 without) and 107 controls. Polymorphisms were identified by PCR-restriction fragment length polymorphism analysis, validated by DNA sequencing with chi-square and multivariate analyses being used to assess possible associations between polymorphisms and OT. Logistic regression under the dominant model revealed a protection factor against OT of the C mutant allele of the IL17F (rs763780) polymorphism. The T/C-C/C genotypes were significantly more common in patients without OT compared to those with OT (p value = 0.0066) and controls (p value = 0.014). Findings from this study suggest that the IL17F polymorphism may have an influence in the immunopathology of OT in Brazilian individuals.

Clinical and epidemiological profile of patients with mental disorders in a specialized outpatient clinic and its role in the psychosocial care network.

Introduction: Mental health disorders (MHDs) are responsible for much impairment of quality of life in Brazil and worldwide. Early diagnosis and effective treatment strategies are required due to the heterogeneous symptoms and multifactorial etiology. Methods: A descriptive retrospective observational study was performed aiming to characterize the clinical and psychiatric profiles of patients with MHD attending a Brazilian public tertiary psychiatric outpatient clinic, which is a reference health service for more than 2 million inhabitants. Predominant clinical and sociodemographic aspects of patients were evaluated between March 2019 and March 2021. Results: A total of 8,384 appointments were analyzed. The majority of patients were female, and the mean age was 45 years old. Generalized anxiety disorder (GAD) was the most common MHD. The prevailing symptoms were sadness, anxiety, and irritability, with the most prescribed medications being selective serotonin reuptake inhibitors. Conclusion: The epidemiological characterization of mental disorders in specialized mental health outpatient clinics provides evidence for the establishment of more specific protocols and advocates a dimensional transdiagnostic approach as an aid to public mental health services.

Portable color retinography findings in COVID-19 patients admitted to the ward.

Retinal lesions, including cotton-wool exudates, microbleeds, vascular occlusions and vasculitis, occur in a minority of Coronavirus Disease-19 (COVID-19) patients. Retinal assessments using retinography can help document these lesions. The objective of this work was to identify retinal changes in patients admitted to the ward with a positive Real Time Quantitative Polymerase Chain Reaction (RT-qPCR) exam for COVID-19. A cross-sectional, observational study was carried out of patients with mild and moderate symptoms admitted to the Hospital de Base in São José do Rio Preto. The Eyer® portable retinal camera (Phelcom® Technologies) was used to evaluate 30 male and 21 female patients. The ages ranged from 21 to 83 years (mean: 47 years). Systemic arterial hypertension was identified in 21 (41.2 %) and diabetes mellitus in 12 (23.5 %) patients. Six (11.7 %) reported worsening visual acuity, however, none of these patients had ocular findings to justify this complaint. Ten patients (19.6 %) had intraretinal hemorrhages; one (1.9 %) had cotton-wool exudates and seven (13.7 %) had dilations of veins. Thirteen patients (25.4 %) had vascular tortuosity and six (11.7 %) had pathological arteriovenous crossings. Portable retinography is useful to evaluate patients admitted to isolation wards due to COVID-19. It is important to remember that some of the patients investigated had comorbidities like diabetic maculopathy and systemic arterial hypertension. Hence, some care should be taken in attributing these observations uniquely to COVID-19 infection.

Seroepidemiology of Toxoplasma gondii infection in blood donors in a population from the northwestern region of São Paulo state, Brazil.

BACKGROUND: Toxoplasmosis is one of the most common parasitic infections worldwide with varying prevalence between human populations. These variations are mainly associated with human exposure to risk factors. In this article, the seroprevalence of Toxoplasma gondii infection and the risk factors associated with infection in 1729 blood donors from São José do Rio Preto, São Paulo, Brazil were analysed. METHODS: The serological tests for detecting immunoglobulin M (IgM) and immunoglobulin G (IgG) anti-T. gondii were used. The risk factors associated with the infection were identified through the application of an epidemiological questionnaire. RESULTS: The prevalence of T. gondii infection was 48.0%. The following factors were identified in the final model after multiple logistic regression analysis: drinking raw milk (p=0.003; odds ratio [OR] 1.364 [confidence interval {CI} 1.1 to 1.7]), residing in a rural area (p<0.0001; OR 2.764 [CI 1.7 to 4.6]) and receiving a blood transfusion (p=0.015; OR 1.856 [CI 1.1 to 3.0]). CONCLUSIONS: The data obtained in this study showed that the blood donor population is exposed to risk factors related to infection by T. gondii. These data allow the establishment of control programs to contribute to public health in northwestern São Paulo state.

Identification and validation of reference genes of circulating microRNAs for use as control in gestational toxoplasmosis.

Toxoplasmosis causes serious harm to the fetus, as tachyzoite dissemination, during pregnancy in women developing the primo-infection. The microRNAs (miRNAs) are small non-coding RNAs, which have regulatory roles in cells by silencing messenger RNA. Circulating miRNA are promising biomarkers for diagnosis and prognosis of numerous diseases. The miRNAs levels are estimated by quantitative real-time PCR (qPCR), however, the relative quantification of each miRNA expression requires proper normalization methods using endogenous miRNAs as control. This study analyzed the expression of three endogenous miRNAs (miR-484, miR -423-3p and miR-26b-5p) for use as normalizers in future studies of target miRNAs for gestational toxoplasmosis (GT). A total of 32 plasma samples were used in all assays divided in 21 from women with GT and 11 from healthy women. The stability of each endogenous miRNA was evaluated by the algorithm methods RefFinder that included GeNorm, Normfinder, BestKeeper and comparative delta-CT programs. The miR-484 was the most stably gene, and equivalently expressed in GT and NC groups. These results contribute to future studies of target miRNAs in clinical samples of women with gestational toxoplasmosis.

miRNA 511_5p is a potential biomarker for ocular toxoplasmosis.

BACKGROUND: Ocular toxoplasmosis (OT) is a frequent clinical manifestation due to infection by Toxoplasma gondii. It is characterized by an inflammatory process involving macrophages activated by pro-inflammatory cytokines. The expression of microRNAs takes place during the inflammatory process and, among them, miRNA 511 regulates the activation of macrophages. This study evaluated the expression of miRNA 511_5p in patients with OT and healthy controls. METHODS: A total of 361 patients from the Hospital de Base of Fundação Faculdade de Medicina de São José do Rio Preto were enrolled and divided into four groups: G1-patients with active ocular lesions and reagent serology for T. gondii; G2-patients with scars and reagent serology for T. gondii; G3-patients without ocular lesions or scars and reagent serology for T. gondii; G4-patients without ocular lesions or scars and non-reagent serology for T. gondii. All patients underwent clinical and laboratory evaluation to confirm the diagnosis of OT. Serology tests, RNA extraction and cDNA synthesis were performed. RESULTS: The miRNA 511_5p levels were compared among the groups. The G1 group showed a high blood plasma concentration of miRNA 511_5p (mean 22.34) compared with the G2 (4.65), G3 (8.91) and G4 (3.52) groups (p<0.0001). CONCLUSION: These data suggest that miRNA 511_5p has significant potential as a biomarker for OT.

Lack of association of the KIR and HLA class I ligands with ZIKV infection in south and southeast of Brazil.

BACKGROUND: Zika virus (ZIKV) is an emerging arbovirus associated with foetal malformations and neurological complications. The infection is usually associated with mild symptoms. The comparison between the allelic frequency of polymorphic genes in symptomatic infected individuals in the population can clarify the pathogenic mechanisms of ZIKV. During ZIKV infection, cytokines are produced and natural killer (NK) cells are recruited, whose activation depends on signaling pathways activated by specific receptors, such as killer cell immunoglobulin-like receptors (KIR). These molecules interact with human leukocyte antigen (HLA) class I ligands and are encoded by polymorphic genes. OBJECTIVES: This study aimed to evaluate the frequency of allelic variants of the genes encoding the KIR receptors and their HLA class I ligands in 139 symptomatic ZIKV-patients and 170 controls negative for the virus, and to evaluate the role of these variants for ZIKV susceptibility. METHODS: KIR and HLA class I genes were genotyped using the polymerase chain reaction-sequence specific oligonucleotide (PCR-SSO) technique. FINDINGS: No significant differences in the frequency distribution of KIRs and KIR-HLA in patients compared to controls were observed. MAIN CONCLUSIONS: KIR and its HLA ligands might play a minor role in ZIKV infection in the south and southeast Brazilian individuals.

HLA-G, LILRB1 and LILRB2 Variants in Zika Virus Transmission from Mother to Child in a Population from South and Southeast of Brazil.

During the 2015-2016 epidemic, Brazil was the country with the highest rate of Zika virus (ZIKV) infection in the Americas. Twenty-nine percent of pregnant women positive for ZIKV exhibited ultrasound scans with fetus anomalies. Human leukocyte antigen-G (HLA-G) exerts immunoregulatory effects by binding to inhibitory receptors, namely LILRB1 and LILRB2, thus preventing mother-fetus rejection and vertical pathogen transmission. The binding of HLA-G to one of its receptors modulates both innate and adaptive immunity. However, in a viral infection, these molecules may behave as pathogenic mediators shifting the pregnancy environment from an anti-inflammatory profile to a pro-inflammatory phenotype. Genetic mutations might be associated with the change in phenotype. This study aimed to explore the possible role of polymorphic sites in HLA-G, LILRB1 and LILRB2 in mother-fetus ZIKV transmission. Polymorphisms were detected by direct sequencing. Differences in allele and/or genotype frequencies for each SNP analyzed among ZIKV non-transmitting and transmitting mother-child pairs, among ZIKV-transmitting and non-transmitting mothers and between ZIKV-infected and non-infected children were compared by Mid-P exact test or Yates' correction. Significant susceptibility of ZIKV vertical transmission is suggested in ZIKV-transmitting and non-transmitting mothers and ZIKV-infected and non-infected children for LILRB1_rs1061684 T/T (p = 0.03, Pc = 0.06, OR = 12.4; p = 0.008, Pc = 0.016, OR = 16.4) and LILRB1_rs16985478 A/A (p = 0.01, Pc = 0.02, OR = 19.2; p = 0.008, Pc = 0.016, OR = 16.4). HLA-G_rs1710 (p = 0.04, Pc = 0.52, OR = 4.30) was also a susceptibility factor. LILRB2_rs386056 G/A (p = 0.02, Pc = 0.08, OR = 0.07), LILRB2_rs7247451 G/G (p = 0.01, Pc = 0.04, OR = 0.04) and HLAG_rs9380142 T/T (p = 0.04, Pc = 0.52, OR = 0.14) were suggested as protective factors against vertical transmission. The current study suggests that polymorphic sites in the LILRB1 and HLA-G genes might be associated with mother-to-child ZIKV transmission while LILRB2 might be associated with protection against ZIKV transmission in the womb in a population from the south and southeast of Brazil.

New artificial intelligence index based on Scheimpflug corneal tomography to distinguish subclinical keratoconus from healthy corneas.

PURPOSE: To assess the efficiency of an index derived from multiple logistic regression analysis (MLRA) to measure differences in corneal tomography findings between subclinical keratoconus (KC) in 1 eye, corneal ectasia, and healthy corneas. SETTING: 2 private Brazilian ophthalmological centers. DESIGN: Multicenter case-control study. METHODS: This study included 187 eyes with very asymmetric ectasia and with normal corneal topography and tomography (VAE-NTT) in the VAE-NTT group, 2296 eyes with healthy corneas in the control group (CG), and 410 eyes with ectasia in the ectasia group. An index, termed as Boosted Ectasia Susceptibility Tomography Index (BESTi), was derived using MLRA to identify a cutoff point to distinguish patients in the 3 groups. The groups were divided into 2 subgroups with an equal number of patients: validation set and external validation (EV) set. RESULTS: 2893 patients with 2893 eyes were included. BESTi had an area under the curve (AUC) of 0.91 with 86.02% sensitivity (Se) and 83.97% specificity (Sp) between CG and the VAE-NTT group in the EV set, which was significantly greater than those of the Belin-Ambrósio Deviation Index (BAD-D) (AUC: 0.81; Se: 66.67%; Sp: 82.67%; P < .0001) and Pentacam random forest index (PRFI) (AUC: 0.87; Se: 78.49%; Sp: 79.88%; P = .021). CONCLUSIONS: BESTi facilitated early detection of ectasia in subclinical KC and demonstrated higher Se and Sp than PRFI and BAD-D for detecting subclinical KC.

TNFα rs1799964 TT genotype may be a susceptibility factor for vertical transmission of Toxoplasma gondii and clinical signs in newborns from pregnant women with acute toxoplasmosis.

BACKGROUND: One of the main impacts of Toxoplasma gondii infection occurs during pregnancy and is related to the vertical transmission of the parasite (congenital toxoplasmosis), which can cause severe clinical outcomes and fetal death. During acute infection, in order to control the rapid replication of tachyzoites, different host immune response genes are activated, and these include cytokine-encoding genes. Considering that polymorphisms in cytokine genes may increase susceptibility to vertical transmission of T. gondii by determining the immune status of the pregnant woman, this study evaluated the influence of polymorphisms of tumor necrosis factor alpha (TNFα) rs1799964 (- 1031) and interleukin 1 beta (IL1ß) rs16944 (- 511) genes on gestational toxoplasmosis and on the vertical transmission of the parasite and verified the allele and genotype frequency of these polymorphisms in pregnant patients whose respective newborn did or did not present clinical abnormalities suggestive of congenital toxoplasmosis. METHODS AND RESULTS: A total of 204 pregnant patients with (n = 114) or without (n = 90) infection by T. gondii were enrolled. No associations were found involving the polymorphisms rs1799964 (- 1031) of the TNFα gene and rs16944 (- 511) of the IL1ß gene with the increased chance of T. gondii infection during pregnancy. However, it was observed that the maternal TT genotype referring to the polymorphism of the TNFα gene seems to influence the vertical transmission of the parasite (P = 0.01; χ2 = 6.05) and the presence of clinical manifestation in newborns from pregnancies with acute toxoplasmosis (P = 0.007; χ2 = 9.68). CONCLUSION: The TNFα rs1799964 TT genotype may act as a susceptibility factor for the vertical transmission of parasite and for the presence of clinical signs in newborns from pregnant women with acute toxoplasmosis.

Absence of significant genetic alterations in the VSX1, SOD1, TIMP3, and LOX genes in Brazilian patients with Keratoconus.

PURPOSE: To identify inherited or acquired mutations in the VSX1, SOD1, TIMP3 and LOX genes from the combined analysis of corneal and blood samples from patients with Keratoconus. METHODS: The casuistry was consisted of samples of peripheral blood and corneal epithelium from 35 unrelated patients with Keratoconus who were submitted to corneal crosslink treatment. Also, blood and corneal epithelium samples from 89 non-keratoconic patients were used to compose the control group. Ophthalmologic evaluations included a clinical examination, topography and tomography. DNA samples were extracted from peripheral blood and from corneal epithelium in both groups and all coding regions of the VSX1, SOD1, TIMP3 and LOX genes were amplified by polymerase chain reaction, denatured and subjected to polyacrylamide gel electrophoresis. Mutational screening was performed by single-strand conformation polymorphism and direct DNA sequencing. RESULTS: No pathogenic variant was found in all coding regions of VSX1, SOD1, TIMP3 and LOX genes, we detected only few SNPs (single-nucleotide polymorphisms). Among the polymorphisms stand out three of them, corresponding to the synonymous exchange of amino acids: exon 3 of VSX1 Ala182Ala and exon 3 of TIMP3 His83His and Ser87Ser; in patients with Keratoconus and also in control subjects. All the polymorphisms were found in samples of corneal epithelium and corresponding blood. CONCLUSION: There is absence of KC pathogenic related to mutations in the VSX1, SOD1, TIMP3 and LOX genes in the studied patients.

Lack of association of the KIR and HLA class I ligands with ZIKV infection in south and southeast of Brazil

BACKGROUND Zika virus (ZIKV) is an emerging arbovirus associated with foetal malformations and neurological complications. The infection is usually associated with mild symptoms. The comparison between the allelic frequency of polymorphic genes in symptomatic infected individuals in the population can clarify the pathogenic mechanisms of ZIKV. During ZIKV infection, cytokines are produced and natural killer (NK) cells are recruited, whose activation depends on signaling pathways activated by specific receptors, such as killer cell immunoglobulin-like receptors (KIR). These molecules interact with human leukocyte antigen (HLA) class I ligands and are encoded by polymorphic genes. OBJECTIVES This study aimed to evaluate the frequency of allelic variants of the genes encoding the KIR receptors and their HLA class I ligands in 139 symptomatic ZIKV-patients and 170 controls negative for the virus, and to evaluate the role of these variants for ZIKV susceptibility. METHODS KIR and HLA class I genes were genotyped using the polymerase chain reaction-sequence specific oligonucleotide (PCR-SSO) technique. FINDINGS No significant differences in the frequency distribution of KIRs and KIR-HLA in patients compared to controls were observed. MAIN CONCLUSIONS KIR and its HLA ligands might play a minor role in ZIKV infection in the south and southeast Brazilian individuals.

Influence of interleukin 17 A and 17 F polymorphisms in keratoconus.

BACKGROUND: Until a few years ago, keratoconus was defined as a noninflammatory degenerative disease. However, recent studies have shown that the altered balance between inflammatory cytokines, proteases, and protease inhibitors, as well as free radicals and oxidants, have a crucial role in the pathogenesis of this disease. The aim of this study is to investigate whether interleukin 17 A G197A (rs2275913) and interleukin 17 F T7488C (rs763780) polymorphisms are associated with keratoconus in patients from a population of the northwestern region of the State of São Paulo, Brazil. METHODS AND RESULTS: 35 patients and 61 controls were enrolled. Genotyping of interleukin 17 A G197A and interleukin 17 F T7488C polymorphisms was carried out using the polymerase chain reaction-restriction fragment length polymorphism technique. Statistical analyses were conducted using the chi-square test, and an odds ratio with a 95% confidence interval was also calculated to evaluate the association between polymorphisms and disease. Evaluating interleukin 17 F T7488C, we found that the TT genotype is associated as a risk factor for keratoconus (P = 0.04; OR = 3.01; CI 1.11-8.14). As for evaluating interleukin 17 A G197A, the allele and genotype frequencies between patients and controls were compared and no statistically significant differences were found. CONCLUSIONS: Our data showed that the interleukin 17 F T7488C polymorphisms may exert an influence in keratoconus.

The Potential Contribution of ABO, Lewis and Secretor Histo-Blood Group Carbohydrates in Infection by Toxoplasma gondii.

The glycosyltransferases encoded by genes from the human ABO, Lewis, and Secretor histo-blood group systems synthesize part of the carbohydrate antigens in hematopoietic and non-hematopoietic tissues. The combined action of these glycosyltransferases strongly influences cell, tissue, mucosa, and exocrine secretion carbohydrate phenotypes, including those serving as habitat for mutualistic and pathogenic microorganisms. A set of reports investigated associations between Toxoplasma gondii infection and the ABO histo-blood group system, but the results are contradictory. As T. gondii uses the gastrointestinal tract as a route for infection, and in this organ, the expression of ABO, Lewis, and Secretor histo-blood group carbohydrates occurs, it is reasonable to suppose some biological relationship between them. This text reviewed association studies published in recent decades focusing on the potential contribution of the ABO, Lewis, and Secretor histo-blood group carbohydrates and infection by T. gondii.

The Role of microRNAs in the Infection by T. gondii in Humans.

MicroRNAs are molecules belonging to an evolutionarily conserved family of small non-coding RNAs, which act on post-transcriptional gene regulation, causing messenger RNA (mRNA) degradation or inhibiting mRNA translation into proteins. These molecules represent potential biomarkers for diagnosis, non-invasive prognosis, and monitoring the development of the disease. Moreover, they may provide additional information on the pathophysiology of parasitic infections and guide strategies for treatment. The Apicomplexan parasite Toxoplasma gondii modifies the levels of microRNAs and mRNAs in infected host cells by modulating the innate and adaptive immune responses, facilitating its survival within the host. Some studies have shown that microRNAs are promising molecular markers for developing diagnostic tools for human toxoplasmosis. MicroRNAs can be detected in human specimens collected using non-invasive procedures. changes in the circulating host microRNAs have been associated with T. gondii infection in mice and ocular toxoplasmosis in humans. Besides, microRNAs can be amplified from samples using sensitive and molecular-specific approaches such as real-time PCR. This review presents recent findings of the role that microRNAs play during T. gondii infection and discuss their potential use of these small nuclei acid molecules to different approaches such as laboratory diagnosis, modulation of cell and tissue infected as other potential applications in human toxoplasmosis.

Detection of anti-Toxoplasma gondiiantibodies in wild free-living birds and mammals from the northwest region of São Paulo state, Brazil / Detecção de anticorpos anti-Toxoplasma gondiiem aves e mamíferos silvestres de vida livre da região noroeste do estado de São Paulo, Brasil

Toxoplasmosis is a protozoonosis caused by an obligate intracellular parasite named Toxoplasma gondii, which can infect humans and a large number of homeothermic animal species with worldwide distribution. The present study aimed to detect anti-T. gondii antibodies from serological samples of free-living wild animals from the northwest region of São Paulo state, Brazil. Thirty-two samples (eight from birds and 24 from mammals) were analyzed by the modified agglutination test (MAT) using 5 cut-off points for birds and 25 for mammals. Seropositivity was observed in 25% (2/8) of birds, including the species Rupornis magnirostris (roadside hawk) and Caracara plancus (southern caracara), and 29.2% (7/24) animals were seropositive among mammals, including one hoary fox (Lycalopex vetulus), two maned wolves (Chrysocyon brachyurus), one black howler monkey (Alouatta caraya), two crab-eating foxes (Cerdocyon thous) and one gray brocket deer (Mazama gouazoubira). The results obtained with the present study indicate the exposure to T. gondiiof free-living wild animals from the northwest region of São Paulo state and, therefore, that they probably play a role in the transmission and maintenance of T. gondii in the environment they inhabit. Thus, identification of the infection in several animal species in the region indicates the environmental contamination of the area. Studies of this nature may help to understand the importance of the prevention and control of this disease in Brazil.(AU)

A toxoplasmose é uma protozoonose causada por um parasita intracelular obrigatório denominado Toxoplasma gondii, que pode infectar os humanos e um vasto número de espécies animais homeotérmicas, apresentando distribuição mundial. O presente estudo objetivou a detecção de anticorpos anti-T. gondii a partir de amostras sorológicas de animais silvestres de vida livre da região noroeste do estado de São Paulo. Foram analisadas 32 amostras (oito de aves e 24 de mamíferos) por meio do teste de aglutinação modificado (MAT), utilizando ponto de corte 5 para as aves e 25 para os mamíferos. Soropositividade foi observada em 25% (2/8) das aves, incluindo as espécies Rupornis magnirostris (gavião-carijó) e Caracara plancus (carcará); entre os mamíferos, 29,2% (7/24) foram soropositivos incluindo uma raposa-do-campo (Lycalopex vetulus), dois lobos-guará (Chrysocyon brachyurus), um bugio-preto (Alouatta caraya), dois cachorros-do-mato (Cerdocyon thous) e um veado-catingueiro (Mazama gouazoubira). Os resultados obtidos com o presente estudo indicam a exposição dos animais selvagens de vida livre a T. gondii na região noroeste do estado de São Paulo e, portanto, que provavelmente apresentam papel na transmissão e manutenção de T. gondii no meio ambiente em que vivem. Assim, a identificação da infecção em várias espécies de animais na região indica a contaminação ambiental da área. Estudos dessa natureza podem ajudar no entendimento sobre a prevenção e o controle dessa importante doença no Brasil.(AU)

Anti-A and anti-A,B monoclonal antisera with high titers favor the detection of A weak phenotypes.

OBJECTIVES: This study aimed to evaluate the reactivity and the titers of commercial anti-A and anti-A,B antisera in the detection of A weak antigen expression in human red blood cells. BACKGROUND: Commercial monoclonal antisera for ABO phenotyping are useful reagents allowing the identification of the four main ABO phenotypes (A, B, AB, and O). However, the reactivity of these commercial reagents can not be evident when the A or B antigens are weakly expressed, and these antisera have low titers. METHODS/MATERIALS: Six samples from blood donors and five samples from patients with ABO forward and reverse discrepant phenotyping were evaluated. The ABO phenotyping was carried out with different commercial monoclonal anti-A and anti-A,B antisera under different temperatures, using test tubes and gel column agglutination. RESULTS: Monoclonal anti-A antisera with titers less than 256 and anti-A,B with titers less than 128 failed to detect the weak expression of A antigen in 73% and 67% of the A weak phenotypes, respectively. Titres equal to or higher than 2048 (anti-A) and 1024 (anti-A,B) showed better reactivity, independent of the cell clone. CONCLUSION: Our data indicate that anti-A and anti-A,B antisera with high titers give better reactivity with red blood cells carrying A weak antigen expression.

Absence of the c.169+50delTAAACAG mutation of SOD1 gene in a sample of keratoconus patients in Brazilian population.

OBJECTIVE: To determine the presence of the 7-bp deletion c.169+50delTAAACAG in intron 2 of Superoxide Dismutase-1 gene in keratoconic patients from the State of São Paulo, Brazil, which promotes splicing variations, resulting in non-functional Superoxide Dismutase-1 antioxidant proteins, which may damage the corneal structure. RESULTS: A group of 35 keratoconic patients, from whom 35 peripheral blood samples and 58 samples of corneal fragments were evaluated, and a control group of 89 individuals, from whom 41 blood samples and 149 samples of corneal fragments were collected. After the amplification of DNA fragments by polymerase chain reaction, mutational screening analysis was performed by enzymatic digestion, followed by direct sequencing. The absence of the 7-bp c.169+50delTAAACAG mutation in intron 2 of Superoxide Dismutase-1 gene was detected in the analyzed subjects of the 2 groups, both in the cornea and peripheral blood samples. Then, according to our results, there is no involvement of c.169+50delTAAACAG deletion in the pathogenesis of keratoconus in this population, once it was not detected. But we emphasize that studies involving this deletion must be continued in an attempt to elucidate this issue.