Chlamydia pneumonia attacks and thrives in vascular endothelial cells, particularly in the lungs, heart and brain. Chlamydia can thrive and replicate in monocytes and macrophages, and in perivascular endothelium and microglial (immune) cells in the brain. Monocytes attack chlamydia pneumonia, and become monocyte-driven macrophages. The monocyte-driven macrophages trigger TNF-alpha, a higher level of inflammation. Infected macrophages have been found adherent to vascular endothelium; and can breach the blood–brain barrier, spreading chlamydia pneumonia to the brain. Infected macrophages are a primary driver of Alzheimer’s disease. (In routine blood chemistry, macrophages are not reported separately and are only reported as monocytes.)

The attached August 2020 article reported macrophages are an important driver of covid19, in both severity and recovery; and the need for better testing for macrophages, to predict severe inflammatory disease and monitor the severity of disease. The article acknowledged concern for co-infection, and describes the potential roles of the endothelium and epithelium in covid19.

Chlamydia pneumonia causes cardiovascular disease; and infects and thrives in endothelium, monocytes, and macrophages. Reading between the lines of the article, diagnosing underlying chronic intracellular infections, that attack endothelium and/or endothelium, infect monocytes and macrophages, and hijack mitochondria, to discover co-infectious pathologies, could be an important line of inquiry for covid19 and other chronic diseases.

https://www.thelancet.com/action/showPdf?pii=S2352-3964%2820%2930340-6