Medical Bulletin 24/January/2023

The error in this case of in-born error of immunity or IEI is a mutation in the gene for the protein IRF4, a transcription factor that is pivotal for the development and function of B and T white blood cells, as well as other immune cells.

In the current study, the consortium identified seven patients from six unrelated families across four continents with profound combination immunodeficiency who experienced recurrent and serious infections, including pneumonia caused by the fungus Pneumocystis jirovecii. Each patient had the same mutation in the DNA-binding domain of IRF4.

Reference:

Rubén Martínez-Barricarte et al,A multimorphic mutation in IRF4 causes human autosomal dominant combined immunodeficiency,Science Immunology,doi 10.1126/sciimmunol.ade7953

New mechanism for MRSA virulence discovered

Researchers at Mount Sinai, in collaboration with researchers at New York University, have published a study that sheds light on the mechanisms behind the severity, or virulence, of methicillin-resistant Staphylococcus aureus (MRSA) blood stream infections. The study, reveals that MRSA has undergone repeated mutations in the sarZ gene, a transcriptional regulator responsible for regulating virulence gene expression, leading to increased severity of blood stream infections in mouse models.

Reference:

Harm van Bakel et al,MRSA lineage USA300 isolated from bloodstream infections exhibit altered virulence regulation,Cell Host & Microbe,doi 10.1016/j.chom.2022.12.003