The ultra-fast speed of the xxpress qPCR thermal cycler is advantageous for a wide variety of uses.

Recently a paper was published in the Journal of Clinical Microbiology detailing the ability of the xxpress to be used for the “timely and exact diagnosis of prosthetic joint infection (PJI)”, a crucial analysis for intra-operative surgical decision-making. In order for this to be possible, results need to be accessible within an hour of sample extraction.

Timely and exact diagnosis of prosthetic joint infection (PJI).


Current Methods

PJI not only creates an enormous burden for individual patients, but also for the health care industry. Currently an alpha-defensin lateral immunoassay of joint fluid is used for precise intra-operative exclusion of PJI. However, this test is not helpful in patients with a limited amount of joint fluid or when the joint fluid is contaminated with blood.

Palacky University realised that additional diagnostic information is contained within the periprosthetic tissues that could reflect the status of the implant pathology more precisely. They investigated this further and found some promising results.


Recent Developments

The paper, published by Palacky University, investigated the gene expression pattern of 12 candidate genes (TLR1, 2, 4, 6, 10, DEFA1, LTF, IL1B, BPI, CRP, IFNG, DEFB4A) and their potential for detecting PJI using periprosthetic tissues from patients and the ultra-fast quantitative RT-PCR xxpress system.


On comparing the mRNA expression levels in PJI patients and aseptic cases, elevated levels of DEFA1IL1BLTFTLR1 and BPI were found. From these, the DEFA1-IL1B-LTF pattern was deduced as the most appropriate for the detection/exclusion of PJI with excellent sensitivity (94.5%) and specificity (95.7%).

Furthermore, when using the ultra-fast xxpress it took just 45 minutes from sample extraction to identify patients with a high probability of PJI. These results look very promising and additional testing with a larger sample of patients is now required.

Just 45 minutes from sample extraction to identify patients with a high probability of PJI.


The full paper titled ‘excellent diagnostic characteristics for ultra-fast gene profiling of DEFA1-IL1B-LTF in the detection of prosthetic joint infections’ can be accessed here.