RESUMO
BACKGROUND & AIMS: It is important to identify individuals with Lynch syndrome because surveillance programs can reduce their morbidity and mortality from colorectal cancer (CRC). We assessed the diagnostic yield of immunohistochemistry to detect Lynch syndrome in patients with advanced and multiple adenomas within our national CRC screening program. METHODS: We performed a prospective study of all participants (n = 1101; 55% male; median age, 66 years; interquartile range, 61-70 years) referred to the Erasmus MC in The Netherlands after a positive result from a fecal immunohistochemical test, from December 2013 to December 2016. Colon tissues were collected from patients with advanced adenomas, ≥4 nonadvanced adenomas, or CRC, and analyzed by immunohistochemistry to identify patients with loss of mismatch repair (MMR) proteins (MLH1, MSH2, MSH6, or PMS2): a marker of Lynch syndrome. Specimens from patients with loss of MLH1 were analyzed for MLH1 promoter hypermethylation. Patients with an MMR-deficient tumor or adenoma without MLH1 promoter hypermethylation were referred for genetic analysis. RESULTS: At colonoscopy, 456 patients (41%) (65% male; mean age, 67 years; interquartile range, 63-71 years) were found to have CRC and/or an adenoma eligible for analysis by immunohistochemistry. Of 56 CRCs, 7 (13%) had lost an MMR protein and 5 had hypermethylation of the MLH1 promoter. Analyses of tumor DNA revealed that 2 patients without MLH1 promoter hypermethylation had developed sporadic tumors. In total, 400 patients with adenomas were analyzed. Of the examined adenomas, 208 (52%) had a villous component and/or high-grade dysplasia: 186 (47%) had a villous component and 41 (10%) had high-grade dysplasia. Only 1 adenoma had lost an MMR protein. This adenoma was found to have 2 somatic mutations in MSH6. CONCLUSIONS: In a CRC screening program in The Netherlands for individuals aged 55 to 75 years, routine screening for Lynch syndrome by immunohistochemistry analysis of colon tissues from patients with advanced and multiple adenomas identified no individuals with this genetic disorder.
Assuntos
Adenoma/genética , Neoplasias Colorretais Hereditárias sem Polipose/genética , Neoplasias Colorretais/genética , Reparo de Erro de Pareamento de DNA/genética , Detecção Precoce de Câncer , Idoso , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais Hereditárias sem Polipose/diagnóstico , Proteínas de Ligação a DNA/genética , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Proteína 1 Homóloga a MutL/genética , Regiões Promotoras Genéticas , Estudos ProspectivosRESUMO
Increased levels of pregnancy zone protein (PZP) were found in the serum of persons who later developed Alzheimer's disease (AD) in comparison to controls who remained dementia free. We suggested that this increase is due to brain derived PZP entering the blood stream during the early phase of the disease. Here we investigate the possible involvement of PZP in human AD pathogenesis. We observed increased PZP immunoreactivity in AD postmortem brain cortex compared to non-demented controls. In the AD cortex, PZP immunoreactivity localized to microglial cells that interacted with senile plaques and was occasionally observed in neurons. Our data link the finding of elevated serum PZP levels with the characteristic AD pathology and identify PZP as a novel component in AD.
Assuntos
Doença de Alzheimer/patologia , Placa Amiloide/metabolismo , Placa Amiloide/patologia , Proteínas da Gravidez/metabolismo , Idoso , Idoso de 80 Anos ou mais , Peptídeos beta-Amiloides/metabolismo , Anticorpos/metabolismo , Receptor 1 de Quimiocina CX3C , Cromatografia Líquida , Diagnóstico , Feminino , Proteína Glial Fibrilar Ácida/metabolismo , Humanos , Imunoprecipitação , Masculino , Pessoa de Meia-Idade , Emaranhados Neurofibrilares/metabolismo , Emaranhados Neurofibrilares/patologia , Fosfopiruvato Hidratase/metabolismo , Proteínas da Gravidez/genética , Proteínas da Gravidez/imunologia , RNA Mensageiro/metabolismo , Receptores de Quimiocinas/metabolismo , Espectrometria de Massas em TandemRESUMO
We have sought for disease-related proteins that could predict the onset of Alzheimer's disease (AD) in a study population derived from the Rotterdam Scan Study, a population-based prospective cohort study designed to investigate the etiology and natural history of age-related brain changes in the elderly. The serum proteome of 43 persons who developed AD, after an average of 4.2 years (±2.6 years SD) after blood sampling, and 43 gender- and age-matched controls who remained dementia-free during follow-up was investigated by liquid chromatography mass spectrometry. We identified 61 differentially expressed peptides between presymptomatic AD and controls, 9 of which were derived from pregnancy zone protein (PZP). Quantitative measurements using a multiple reaction monitoring assay showed a significant increase in concentration of PZP in presymptomatic AD (34.3 ± 20.6 mg/L) compared with controls (23.6 ± 13.6 mg/L) (p = 0.006). The difference in PZP was significant in women. Immunohistochemical validation of the findings on brain tissue sections showed strong PZP expression in senile plaques and in microglial and glial cells in AD with only low expression in some scattered glial cells in controls.
