A Ginger Root or Plum Model for the Tuberculosis "Granuloma"?

Giving volume to the elephant in the imaging room

Rudolf Virchow, the founder of cellular pathology, held that even when physical or chemical investigations yield the laws of physiology or medicine, the anatomist can still proudly state: This is the structure in which the law becomes manifest. In his words, "physiology presupposes anatomy." Pathological anatomy studies, at usual microstructural scales (approximately 1-100 μm), via light microscopic 2D histology, provided many insights into structure-function relationships of health and disease. For example, such studies established the progression of granulomas, bronchial erosions, microcavities, and destructive lung disease in tuberculosis. While histologic studies remain the cornerstone of such efforts, the advent of nano or micro-X-ray computed tomography (n/μCT) has now made it additionally possible to obtain 3D visualizations of soft and hard tissues, while preserving the tissue for additional investigations. This has applications for old as well as new diseases (Katsamenis et al, 2019; Tanabe & Hirai, 2021).

Anti-tuberculosis treatment strategies and drug development: challenges and priorities

Despite two decades of intensified research to understand and cure tuberculosis disease, biological uncertainties remain and hamper progress. However, owing to collaborative initiatives including academia, the pharmaceutical industry and non-for-profit organizations, the drug candidate pipeline is promising. This exceptional success comes with the inherent challenge of prioritizing multidrug regimens for clinical trials and revamping trial designs to accelerate regimen development and capitalize on drug discovery breakthroughs. Most wanted are markers of progression from latent infection to active pulmonary disease, markers of drug response and predictors of relapse, in vitro tools to uncover synergies that translate clinically and animal models to reliably assess the treatment shortening potential of new regimens. In this Review, we highlight the benefits and challenges of 'one-size-fits-all' regimens and treatment duration versus individualized therapy based on disease severity and host and pathogen characteristics, considering scientific and operational perspectives.