Comparison of Quick Lactose Intolerance Test in duodenal biopsies of dyspeptic patients with single nucleotide polymorphism LCT-13910C>T associated with primary hypolactasia/lactase-persistence

• Autor(a) principal: Mattar,Rejane
• Data de Publicação: 2013
• Outros Autores: Basile-Filho,Anibal, Kemp,Rafael, Santos,José Sebastião dos
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Acta Cirúrgica Brasileira (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0102-86502013001300015
• topic: Lactose Intolerance; Endoscopy; Biopsy; Nutrition; Public Health

PURPOSE: To analyze the usefulness of Quick Lactose Intolerance Test in relation to the genetic test based on LCT-13910C&gt;T genotypes, previously validated for clinical practice, for primary hypolactasia/lactase-persistence diagnosis. METHODS: Thirty-two dyspeptic patients that underwent upper gastrointestinal endoscopy entered the study. Two postbulbar duodenal biopsies were taken for the Quick test, and gastric antral biopsy for DNA extraction and LCT-13910C&gt;T polymorphism analysis. DNA was also extracted from biopsies after being used in the Quick Test that was kept frozen until extraction. RESULTS: Nine patients with lactase-persistence genotype (LCT-13910CT or LCT-13910TT) had normolactasia, eleven patients with hypolactasia genotype (LCT-13910CC) had severe hypolactasia, and among twelve with mild hypolactasia, except for one that had LCT-13910CT genotype, all the others had hypolactasia genotype. The agreement between genetic test and quick test was high (p<0.0001; Kappa Index 0.92). Most of the patients that reported symptoms with lactose-containing food ingestion had severe hypolactasia (p<0.05). Amplification with good quality PCR product was also obtained with DNA extracted from biopsies previously used in the Quick Test; thus, for the future studies antral gastric biopsies for genetic test would be unnecessary. CONCLUSION: Quick test is highly sensitive and specific for hypolactasia diagnosis and indicated those patients with symptoms of lactose intolerance.