RESUMO
BACKGROUND: The study of HLA classes I and II in Brazilian psoriasis patients may contribute to a better understanding of their association with the disease. OBJECTIVE: To describe HLA classes I and II of Brazilian patients with psoriasis, with or without arthritis, compare them to controls and correlate HLA markers with epidemiological and evolutional aspects of psoriasis. METHODS: A total of 55 patients with more than 5 years of psoriasis, with or without arthritis, answered a questionnaire on ethnic background and disease severity. A total of 134 bone marrow donors were controls. HLA class I and II genotyping was determined by PCR-SSP. RESULTS: Mean age was 42.4 years; 23 women and 32 men. HLA-B*57 was present in 23.6% patients and in 7.5% controls (p=0.00200, OR= 3.8381), and HLA-C*06 in 29.1% patients and in 16.4% controls (p= 0.04832, OR=2.0886). HLA-B*57 and HLA-C*18 were significantly present in patients with arthritis (p=0.00104, OR=6.6769 and p=0.00269, OR=16.50, respectively). HLA-B*57 was significantly present in patients with history of erythroderma (p=0.00548, OR= 5.1059), as was HLA-C*06 (p=0.02158, OR=3.0545). HLA-B*57 was also frequent in patients with history of hospital internment due to psoriasis (p= 0.00094, OR=7.8909) and in the ones with history of systemic treatment for psoriasis (p= 0.00011, OR= 5.3733). Haplotype HLA-A*02 B*57 C*06 DRB1*07DQB1*03 was the most common among the patients (p= 0.00069, OR= 3.528). CONCLUSION: HLA-B*57 and HLA-C*06 were significantly increased in the patients indicating risk for psoriasis. HLA-B*57 remained high in patients with history of erythroderma, hospital internment, systemic treatment, and psoriatic arthritis, showing association with disease severity. HLA-C*18 was significantly high only in patients with psoriatic arthritis. HLA-B*57 and HLA-C*06 and haplotype HLA-A*02B*57Cw*06DRB1*07 DQB1*03 seen in this study were already described before, associated with psoriasis. HLA-Cw*18 was not described in other populations in association with psoriasis.
RESUMO
BACKGROUND: Brazil has seen a great decline in malaria and the country is moving towards elimination. However, for eventual elimination, the control program needs efficient tools in order to monitor malaria exposure and transmission. In this study, we aimed to evaluate whether seroprevalence to the circumsporozoite protein (CSP) is a good tool for monitoring the exposure to and/or evaluating the burden and distribution of Plasmodium species in the Brazilian Amazon. METHODS: Cross-sectional surveys were conducted in a rural area of Porto Velho, Rondônia state. Parasite infection was detected by microscopy and polymerase chain reaction. Antibodies to the sporozoite CSP repeats of Plasmodium vivax, P. falciparum, and P. malariae (PvCS, PfCS, and PmCS) were detected using the enzyme-linked immunosorbent assay technique. Human leukocyte antigen (HLA)-DRB1 and DQB1 genes were typed using Luminex® xMAP® technology. RESULTS: The prevalence of immunoglobulin G against P. vivax CSP peptide (62%) was higher than P. falciparum (49%) and P. malariae (46%) CSP peptide. Most of the studied individuals had antibodies to at least one of the three peptides (72%), 34% had antibodies to all three peptides and 28% were non-responders. Although the majority of the population was not infected at the time of the survey, 74.3% of parasite-negative individuals had antibodies to at least one of the CSPs. Importantly, among individuals carrying the haplotypes DRB1*04~DQB1*03, there was a significantly higher frequency of PfCS responders, and DRB1*16~DQB1*03 haplotype for PvCS and PfCS responders. In contrast, HLA-DRB1*01 and HLA-DQB1*05 allelic groups were associated with a lack of antibodies to P. vivax and P. falciparum CSP repeats, and the haplotype DRB1*01~DQB1*05 was also associated with non-responders, including non-responders to P. malariae. CONCLUSIONS: Our results show that in low transmission settings, naturally acquired antibody responses against the CSP repeats of P. vivax, P. falciparum, and P. malariae in a single cross-sectional study may not represent a valuable marker for monitoring recent malaria exposure, especially in an area with a high prevalence of P. vivax. Furthermore, HLA class II molecules play an important role in antibody response and require further study with a larger sample size. It will be of interest to consider HLA analysis when using serosurveillance to monitor malaria exposure among genetically diverse populations.
Assuntos
Anticorpos Antiprotozoários/sangue , Malária/epidemiologia , Plasmodium/isolamento & purificação , Proteínas de Protozoários/imunologia , Adolescente , Adulto , Brasil/epidemiologia , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , População Rural , Estudos Soroepidemiológicos , Especificidade da Espécie , Adulto JovemRESUMO
BACKGROUND: Brazil has seen a great decline in malaria and the country is moving towards elimination. However, for eventual elimination, the control program needs efficient tools in order to monitor malaria exposure and transmission. In this study, we aimed to evaluate whether seroprevalence to the circumsporozoite protein (CSP) is a good tool for monitoring the exposure to and/or evaluating the burden and distribution of Plasmodium species in the Brazilian Amazon. METHODS: Cross-sectional surveys were conducted in a rural area of Porto Velho, Rondônia state. Parasite infection was detected by microscopy and polymerase chain reaction. Antibodies to the sporozoite CSP repeats of Plasmodium vivax, P. falciparum, and P. malariae (PvCS, PfCS, and PmCS) were detected using the enzyme-linked immunosorbent assay technique. Human leukocyte antigen (HLA)-DRB1 and DQB1 genes were typed using Luminex® xMAP® technology. RESULTS: The prevalence of immunoglobulin G against P. vivax CSP peptide (62%) was higher than P. falciparum (49%) and P. malariae (46%) CSP peptide. Most of the studied individuals had antibodies to at least one of the three peptides (72%), 34% had antibodies to all three peptides and 28% were non-responders. Although the majority of the population was not infected at the time of the survey, 74.3% of parasite-negative individuals had antibodies to at least one of the CSPs. Importantly, among individuals carrying the haplotypes DRB1*04~DQB1*03, there was a significantly higher frequency of PfCS responders, and DRB1*16~DQB1*03 haplotype for PvCS and PfCS responders. In contrast, HLA-DRB1*01 and HLA-DQB1*05 allelic groups were associated with a lack of antibodies to P. vivax and P. falciparum CSP repeats, and the haplotype DRB1*01~DQB1*05 was also associated with non-responders, including non-responders to P. malariae. CONCLUSIONS: Our results show that in low transmission settings, naturally acquired antibody responses against the CSP repeats of P. vivax, P. falciparum, and P. malariae in a single cross-sectional study may not represent a valuable marker for monitoring recent malaria exposure, especially in an area with a high prevalence of P. vivax. Furthermore, HLA class II molecules play an important role in antibody response and require further study with a larger sample size. It will be of interest to consider HLA analysis when using serosurveillance to monitor malaria exposure among genetically diverse populations