Knee osteoarthritis is a leading cause of pain and disability and frequently results in total knee arthroplasty (TKA). Decisions about surgery and postoperative management rely largely on subjective pain scales and patient-reported outcome measures (PROMs), and 10–15% of patients remain dissatisfied after TKA despite technically successful surgery. Evidence suggests that pain is partly reflected in peripheral immune signalling, yet this neuroimmune interface has not been studied in patients with joint pain due to knee osteoarthritis. This study will explore whether peripheral immune responses (interleukin-1 beta, IL-1β) are associated with pain and may serve as objective pain biomarkers in patients with painful knee osteoarthritis compared with pain-free controls and how these markers relate to pain and psychological (anxiety, depression and pain catastrophising) PROMs. This will be the first study to correlate pain markers (peripheral immune responses) with subjective pain levels in orthopaedic patients with symptomatic knee osteoarthritis.

This is a protocol for a prospective cross-sectional matched-subject observational study. We will include 20 adults undergoing unilateral primary TKA for painful advanced knee osteoarthritis, their contralateral pain-free knees as internal controls and 20 age and sex matched healthy controls without joint pain or functional limitation. All participants will undergo standardised clinical assessment and complete pain and psychological PROMs. In patients with TKA, venous blood will be collected pre-operatively. During TKA surgery, synovial fluid will be aspirated from the painful operated knee and the contralateral pain-free knee. Healthy controls will provide a single venous blood sample at a hospital visit. Peripheral blood mononuclear cells and synovial fluid mononuclear cells will be stimulated ex vivo with toll-like receptor 2 and 4 agonists to quantify IL-1β release. In parallel, hyperspectral imaging will characterise unstimulated immune cell phenotypes. Multivariable statistical and machine-learning approaches will relate biomarker profiles to pain and psychological PROMs.

The study has been approved by the Southern Adelaide Local Health Network (SALHN) HREC (references: 2024/HRE00253, SSA 2024/SSA00641). Written informed consent will be obtained from all participants. Study results will be disseminated through peer-reviewed publications and presentations at national and international scientific conferences.

ACTRN12626000084381.

Tuberculosis (TB) remains a significant public health challenge in many African communities, where underreporting and underdiagnosis are prevalent due to barriers in accessing care and inadequate diagnostic tools. This is particularly concerning in hard-to-reach areas with a high burden of TB/HIV co-infection, where missed or delayed diagnoses exacerbate disease transmission, increase mortality and lead to severe economic and health consequences. To address these challenges, it is crucial to evaluate innovative, cost-effective, community-based screening strategies that can improve early detection and linkage to care.

We conduct a prospective, community-based, diagnostic, pragmatic trial in communities of the Butha Buthe District in Lesotho and the Greater Edendale area of Msunduzi Municipality, KwaZulu-Natal in South Africa to compare two strategies for population-based TB screening: computer-aided detection (CAD) technology alone (CAD4TBv7 approach) versus CAD combined with point-of-care C reactive protein (CRP) testing (CAD4TBv7-CRP approach). Following a chest X-ray, CAD produces an abnormality score, which indicates the likelihood of TB. Score thresholds informing the screening logic for both approaches were determined based on the WHO’s target product profile for a TB screening test. CAD scores above a threshold prespecified for the CAD4TBv7 approach indicate confirmatory testing for TB (Xpert MTB/RIF Ultra). For the CAD4TBv7-CRP approach, a CAD score within a predefined window requires the conduct of the second screening test, CRP, while a score above the respective upper threshold is followed by Xpert MTB/RIF Ultra. A CRP result above the selected cut-off also requires a confirmatory TB test. Participants with CAD scores below the (lower) threshold and those with CRP levels below the cut-off are considered screen-negative. The trial aims to compare the yield of detected TB cases and cost-effectiveness between two screening approaches by applying a paired screen-positive design. 20 000 adult participants will be enrolled and will receive a posterior anterior digital chest X-ray which is analysed by CAD software.

The protocol was approved by National Health Research Ethics Committee in Lesotho (NH-REC, ID52-2022), the Human Sciences Research Council Research Ethics Committee (HSRC REC, REC 2/23/09/20) and the Provincial Health Research Committee of the Department of Health of KwaZulu-Natal (KZ_202209_022) in South Africa and from the Swiss Ethics Committee Northwest and Central Switzerland (EKNZ, AO_2022–00044). This manuscript is based on protocol V.4.0, 19 January 2024. Trial findings will be disseminated through peer-reviewed publications, conference presentations and through communication offices of the consortium partners and the project’s website (https://tbtriage.com/).

ClinicalTrials.gov (NCT05526885), South African National Clinical Trials Register (SANCTR; DOH-27-092022-8096).