Navorsers aan die Universiteit Stellenbosch (US) was betrokke by 'n insiggewende ontdekking oor hoe sommige individue tuberkulose (TB) beveg.

Die navorsing is op 22 Augustus 2018 in die wetenskaplike joernaal, Nature, asook in 'n meegaande mediaverklaring (sien onder), bekend gemaak.

Prof Gerhard Walzl en dr Stephanus Malherbe van die DWT/NNS Sentrum van Uitnemendheid vir Biomediese Tuberkulosenavorsing aan die US se Fakulteit Geneeskunde en Gesondheidswetenskappe was deel van 'n internasionale navorsingspan wat die rol van natuurlike doderselle ('natural killer cells') in die ontwikkeling van aktiewe TB-infeksies ondersoek het.

Natuurlike doderselle is deel van die menslike immuunstelsel. Dié witbloedselle kom natuurlik voor en vernietig sekere bakterieë, virusse en ander organismes wat siektes veroorsaak, dikwels deur die menslike selle dood te maak wat deur hierdie patogene besmet of beskadig is.

Tydens die studie het die wetenskaplikes die vlakke van natuurlike doderselle vergelyk in mense met geen TB-infeksies, mense met latente TB-infeksies (gesonde pasiënte met die infeksie maar geen simptome) en mense met aktiewe TB-infeksies (siek pasiënte met simptome).

Die navorsers het gevind dat mense met latente TB hoër vlakke van doderselle het, terwyl mense met aktiewe TB laer vlakke van die selle getoon het. Pasiënte se doderselle het toegeneem wanneer hulle behandeling ontvang het en van die siekte herstel het. Dié bevinding suggereer dat natuurlike doderselle moontlik 'n beskermende rol in die konteks van TB-infeksies speel.

Boonop sal die meting van natuurlike doderselle na verwagting gebruik kan word om die ernstigheid van TB-infeksies te bepaal en die verloop van die siekte en behandeling te monitor.

Die manier waarop die navorsing uitgevoer is, is ook noemenswaardig. Die wetenskaplikes het komplekse data ontleed wat deur datadeling-ooreenkomste van drie afsonderlike kliniese studies verkry is. Dit is 'n voorbeeld van 'n nuwe neiging by instellings en finansiers om datadeling te bevorder om navorsingbevindinge te optimiseer.

Vir meer inligting, sien die mediaverklaring deur Nature hier onder.

MEDIAVERKLARING VAN NATURE

Infectious diseases: Natural killers associated with latent tuberculosis

Higher levels of natural killer cells are associated with tuberculosis latency, reports a paper published online this week in Nature. The findings raise the question as to whether natural killer cells might play an active role in controlling tuberculosis infections.

Tuberculosis (TB) is a bacterial disease and a leading cause of infection-related deaths. The majority of TB infections are latent — manifesting, without outward symptoms, in a contained state. It is estimated that a quarter of the world's population has latent TB, although fewer than 10% of latent TB cases end up progressing to an active state. The immune factors that influence a given individual's infection outcome, however, are poorly understood.

To investigate the immune state that leads to latency and how that changes if the disease progresses, Yueh-hsiu Chien and colleagues conducted studies of various human cohorts combining mass cytometry analysis with an examination of gene expression datasets to identify differences in immune cell populations between uninfected subjects and those with latent or active TB.

They find that latent manifestations of TB are associated with higher numbers of natural killer cells — white blood cells that can kill certain pathogens — with enhanced anti-toxin responses in comparison to uninfected individuals. In subjects with an active infection, levels of natural killer cells were diminished, but abundances returned to baseline levels when the infection was cured. However, the findings cannot prove a causal relationship between natural killer cells and TB latency. 

Additionally, the authors show that measurements of natural killer cell levels can be used to determine the activity level and burden of TB infection in a patient's lungs — a finding that could help to assess disease progression and optimize treatments.

CONTACT 

Yueh-hsiu Chien (Stanford University School of Medicine, Stanford, CA, USA) 

Tel: +1 650 723 1078; E-mail: [email protected]

Please link to the scientific paper in online versions of your report (the URL will go live after the embargo ends): 

http://dx.doi.org/10.1038/s41586-018-0439-x