Diagnosis of Constitutional Mismatch Repair-Deficiency Syndrome Based on Microsatellite Instability and Lymphocyte Tolerance to Methylating Agents.

Background & Aims: Patients with bi-allelic germline mutations in mismatch repair (MMR) genes (MLH1, MSH2, MSH6, or PMS2) develop a rare but severe variant of Lynch syndrome called constitutional MMR deficiency (CMMRD). This syndrome is characterized by early-onset colorectal cancers, lymphomas or leukemias, and brain tumors. There is no satisfactory method for diagnosis of CMMRD because screens for mutations in MMR genes are noninformative for 30% of patients.

Procalcitonin predicts response to beta-lactam treatment in hospitalized children with community-acquired pneumonia.

Background: Antibiotic treatment of community-acquired pneumonia (CAP) in children remains mostly empirical because clinical and paraclinical findings poorly discriminate the principal causes of CAP. Fast response to beta-lactam treatment can be considered a proxy of pneumococcal aetiology. We aimed to identify the best biological predictor of response to beta-lactam therapy in children hospitalized for CAP.