Loop-Mediated Isothermal Amplification Enables Reliable Kaposi Sarcoma Diagnosis Across Time and Sites in East Africa.

Kaposi sarcoma (KS) is an endothelial cancer caused by the Kaposi sarcoma-associated herpesvirus (KSHV), and it remains one of the most frequently diagnosed and fatal cancers in sub-Saharan Africa. Achieving timely and accurate diagnosis for KS is a critical challenge in sub-Saharan Africa, where access to histopathology is limited and clinical diagnosis is often erroneous. Previously, a point-of-care device was developed to quantify KSHV DNA and demonstrated promising performance, achieving 97% sensitivity and 92% specificity at a 26-min threshold in a training set of patients from several Ugandan clinics. Herein, 421 skin biopsies from a different, test set of patients identified later in calendar time at the same clinical sites were examined using the same methodology. Using the previously defined cutoff threshold, the test achieved similarly high sensitivity (95%) and specificity (90%), confirming the robustness of the threshold-based assay across both clinical settings and time. This multi-site, temporally distinct validation supports the further development of a nucleic acid-based KS diagnostic test and holds strong potential for improving early KS diagnosis access in high-burden, resource-limited regions.