Peritoneal dialysis (PD) is becoming widely accepted as a preferred method for managing end-stage renal disease as it offers greater patient mobility and independence compared to other dialysis options, as well as being gentler to residual kidney function in early stage disease. PD usage around the world is increasing, slowly driven by the benefits of lower cost, increased patient mobility, and the ability to continue in the workforce, but hampered by a lack of sufficient numbers of trained staff, clinical assumptions, and concerns about risk of infection. PD requires the infusion of a sugar solution into the peritoneal cavity of a patient, where it dwells for a period of time, usually up to four hours. During this time the metabolic toxins in the blood diffuse passively into the dialysis fluid which is then drained off. Infusion of the bag contents is achieved through the surgical insertion of a catheter that crosses into the peritoneal cavity. Unfortunately this catheter can also be the Achilles heel of the treatment as it requires the patient, or their carer, to be highly proficient in hygiene techniques to ensure an infection doesn’t compromise the line or infect the bag contents. Infections can lead to the need for emergency treatment with antibiotics, replacement of the catheter, and potentially causes peritoneal lining damage or scarring that may prevent the long-term use of this treatment.

Unfortunately, peritonitis is a leading cause of patients transferring to more expensive haemodialysis. Rates of infection vary greatly from country to country, and sometimes even within countries but for some people, infection is an ongoing and recurring problem. The current method of diagnosis is for patients to check the waste bag for cloudiness. If a cloudy bag is observed, they are then advised to visit their renal clinic, or A&E Dept. if outside normal hours where the patient is examined

and the bag sent to the laboratory where a white blood cell count will be performed, and a sample will also be cultured. A white cell count can take anything from 30 minutes to four hours before it’s available in the clinic, so the patient is often put on antibiotics as a precautionary measure. Once a course of antibiotics has been started, it is usually continued even if the culture result is negative (and this would normally take two to three days).

We at Mologic have designed a point-of-care device that patients on PD are now able to use in their own homes and test for infection. We are hoping this will lead to faster diagnosis and treatment for patients where infection is detected, but also help to reduce unnecessary visits to healthcare providers and the inappropriate use of antibiotics. We have based PERiPLEXon the same lateral flow technology used in home-use pregnancy tests, so it’s very simple to use with results being determined by the presence or absence of either of two test lines. The barrel of the sample device is designed to attach to the outlet port of the waste dialysate bag, with a concealed needle included in it which pierces the septum of the port. After five to ten seconds, enough fluid has entered the device via the needle, so the device is then detached and laid flat for five minutes. After five minutes, a visual check is made for the presence of any pink lines. There should always be one line showing which is the control line – this provides a procedural check that the test has been run correctly i.e. that enough fluid has been added. If any additional lines are also present, this means that the test is positive and the patient should seek medical assistance.

We are delighted that PERiPLEX has recently received CE-mark approval and as with all of our products which are either CE-marked or in development, the biggest hurdle has been access to clinical samples. Given the relatively low incidence of peritonitis in these patients, it has been a particular difficulty for this product. This was the first Mologic product to be CE-marked, so there was a lot to be learned about the regulatory requirements, and as this product is for home use these are more exacting than for products designed for professional use. There is little doubt that point-of-care devices offer great benefit to patients, clinicians and the wider healthcare economy, and that they will play an increasingly important and significant role in the future of healthcare.There is a global trend towards keeping patients out of hospital as much as possible, with point-of-care tests for both home use and primary care professional use absolutely key to enabling this. Earlier diagnosis leads to earlier correct treatment, which should mean fewer complications so not only are patient outcomes better, but there should also be significant cost savings. How ever, when developing devices like PERiPLEX for home use, it’s vital that the end user, i.e. the patient, is involved to provide their input. Any device for home use has to be easy to use for the patient otherwise they just won’t use it, and the results also have to be easy to interpret. Patients know what their problems are which might not even occur to someone not in their situation. The instructions for use also have to be extremely clear, and not assume any prior knowledge or experience, whereas when developing devices for laboratory use, it is assumed that a certain level of training is available.