Ocular toxoplasmosis with positive polymerase chain reaction in peripheral blood ­ report of two cases, São Paulo State, Brazil / Toxoplasmose ocular com reação em cadeia da polimerase positiva em sangue periférico ­ relato de dois casos, estado de São Paulo, Brasil

Aims: To describe the use of polymerase chain reaction (PCR) in peripheral blood and demonstrate its importance in the clinical follow-up of patients with ocular toxoplasmosis. Case description: Two immunocompetent patients were clinically diagnosed with acute ocular toxoplasmosis. The routine clinical evaluation consisted of fundus examination using binocular indirect ophthalmoscopy, color fundus photography, fluorescein angiography, and spectral domain optical coherence tomography. The serological diagnosis was made by enzyme-linked immunosorbent assay (ELISA) and confirmed by enzyme-linked fluorescent assay (ELFA). The molecular diagnosis was made by PCR in peripheral blood using the B1 gene of Toxoplasma gondii as marker. The younger patient was male, had previous lesion in the right eye, complained of low visual acuity in the left eye and was under treatment. The older patient was male, had retinal detachment, and presented with sudden loss of acuity in the right eye. The fundus examination revealed chorioretinal scar in the left eye. IgG was reactive, IgM was non-reactive, and PCR was positive in the peripheral blood of both patients. New blood samples were collected for serological and molecular monitoring and PCR remained positive in both cases. Six weeks after treatment with oral sulfadiazine and pyrimethamine, the PCR yielded negative results. Conclusion: The results show that T. gondii antigens may be found in peripheral blood during ocular reactivations and that PCR may be a good tool for the follow-up of patients with ocular toxoplasmosis.

Objetivos: Descrever o uso da reação em cadeia da polimerase (PCR) no sangue periférico e demonstrar sua importância no acompanhamento clínico de pacientes com toxoplasmose ocular. Descrição dos casos: Dois pacientes imunocompetentes foram clinicamente diagnosticados com toxoplasmose ocular aguda. Rotineiramente, a avaliação clínica foi feita por fundoscopia com o uso de oftalmoscópio binocular indireto, retinografia colorida, angiografia fluorescente e tomografia de coerência óptica espectral. A sorologia foi realizada por ensaio imunoenzimático (ELISA) e confirmada por ensaio imunoenzimático fluorescente ELFA (IgG, IgM). O diagnóstico molecular foi realizado por PCR em sangue periférico usando o gene B1 de Toxoplasma gondii como marcador. O paciente mais jovem era do sexo masculino, apresentava lesão prévia no olho direito, queixa de baixa acuidade visual no olho esquerdo e estava sob tratamento. O paciente mais velho era do sexo masculino, apresentava descolamento de retina e súbita diminuição de visão no olho direito. A fundoscopia revelou cicatriz coriorretiniana no olho esquerdo. Ambos os pacientes tinham IgG reagente, IgM não reagente e PCR positivo em sangue periférico. Novas amostras de sangue foram coletadas para monitoramento sorológico e molecular e a PCR permaneceu positiva em ambos os casos. Seis semanas após o início do tratamento com sulfadiazina e pirimetamina oral, os resultados do PCR tornaram-se negativos. Conclusões: Os resultados mostram que antígenos de T. gondii podem ser encontrados em sangue periférico durante as reativações oculares e que a PCR parece ser uma boa ferramenta para o acompanhamento de pacientes com toxoplasmose ocular.

Evidence of an association between the O blood group and allergic rhinitis

OBJECTIVE: The aim of this study was to verify if ABO phenotypes are associated with allergic rhinitis. METHODS: 168 patients with allergic rhinitis and 168 control individuals from the same geographical region and paired by gender and age were enrolled in the study. ABO phenotypes were identified in red blood cells using the hemagglutination technique. The Fisher exact and chi-squared tests were employed to compare proportions. Statistical significance was set for an alpha error of 5 percent (p-value < 0.05). RESULTS: The overall differences in the frequencies of the ABO phenotypes of patients and controls were marginal (χ2: 7.569; degrees of freedom (DF): 3; p-value = 0.055) however the O blood group was associated with allergic rhinitis (χ2: 5.764; DF: 1; p-value = 0.016; OR: 1.735; CI 95 percent: 1.127-2.673). The differences in the frequencies of the O phenotype in patients and controls were statistically different for men (χ2: 8.520; DF: 1; p-value = 0.003) but not for women (χ2: 0.6375; DF: 1; p-value = 0.4246). The A phenotype was associated with protection (OR: 0.4385; CI 95 percent: 0.2043-0.9415; p-value = 0.049) and the O phenotype was associated with susceptibility (OR = 2.789; CI 95 percent: 1.385-5.616; p-value = 0.005) to allergic rhinitis only for men. CONCLUSION: The O blood group phenotype is associated with allergic rhinitis in male but not in female patients.

Anti-Toxoplasma gondii antibodies in pregnant women and their newborn infants in the region of São José do Rio Preto, São Paulo, Brazil / Anticorpos anti-Toxoplasma gondii em gestantes e seus neonatos na região de São José do Rio Preto, São Paulo, Brazil

CONTEXT AND OBJECTIVE: Toxoplasmosis transmission during pregnancy can cause severe sequelae in fetuses and newborns. Maternal antibodies may be indicators of risk or immunity. The aim here was to evaluate seropositivity for anti-Toxoplasma gondii (anti-T. gondii) immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies and IgG avidity in pregnant women and their newborn infants. DESIGN AND SETTING: Cross-sectional study in a high-risk pregnancy outpatient clinic. METHODS: Serum samples from pregnant women (n = 87) and their respective newborns (n = 87) were evaluated for anti-T. gondii antibodies using indirect immunofluorescence (IIF) (IgM and IgG), enzyme-linked immunosorbent assay (ELISA) (IgG) and an avidity test. RESULTS: Anti-T. gondii antibodies were identified in 64.4 percent of the serum samples from the mothers and their infants (56/87). Except for two maternal serum samples (2.3 percent), all others were negative for anti-T. gondii IgM antibodies, using IIF. The results showed that 92.9 percent of the pregnant women had high IgG avidity indexes (> 30 percent) and four samples had avidity indexes between 16 and 30 percent. Two women in the third trimester of pregnancy were positive for anti-T. gondii IgM antibodies; their babies had avidity indexes between 16 and 30 percent. The avidity indexes of serum from the other 83 newborns were similar to the results from their mothers. CONCLUSIONS: The results showed that 2 percent of the pregnant women were at risk of T. gondii transmission during the gestational period. These data seem to reflect the real situation of gestational toxoplasmosis in the northwestern region of the state of São Paulo.

CONTEXTO E OBJETIVOS: A toxoplasmose, quando transmitida durante a gestação, pode causar graves sequelas em fetos e neonatos. Anticorpos maternos podem ser indicadores de risco ou de imunidade. O objetivo foi avaliar a positividade dos anticorpos das classes imunoglobulina M (IgM) e imunoglobulina G (IgG) anti-Toxoplasma gondii (anti-T. gondii), bem como a avidez de IgG em gestantes e seus neonatos. TIPO DE ESTUDO E LOCAL: Estudo transversal em ambulatório de gestação de alto risco. MÉTODOS: Anticorpos anti-T. gondii foram avaliados em amostras de soro de gestantes (n = 87) e seus respectivos neonatos (n = 87) com o uso dos métodos imunofluorescência indireta (IFI) (IgM e IgG), ensaio imunoenzimático (ELISA) (IgG) e avidez. RESULTADOS: Anticorpos anti-T. gondii foram identificados em 64,4 por cento das amostras de soro das mães e seus bebês (56/87). Com exceção de duas amostras de soro materno (2,3 por cento), todas as demais foram negativas anticorpos IgM anti-T. gondii determinado pela IFI. Os resultados mostraram que 92,9 por cento das gestantes tinham índices elevados de avidez de IgG (> 30 por cento) e 4 amostras apresentaram índices de avidez entre 16-30 por cento. Duas gestantes no terceiro trimestre da gravidez eram positivas IgM anti-T. gondii; seus bebês apresentaram índices de avidez entre 16 e 30 por cento. Os índices de avidez dos soros dos outros 83 recém-nascidos foram semelhantes àqueles encontrados nas amostras maternas. CONCLUSÕES: Os resultados mostraram que 2 por cento das gestantes estavam sob risco de transmissão de T. gondii durante o período gestacional. Estes dados parecem refletir a real situação da toxoplasmose gestacional na região noroeste do Estado de São Paulo.