Direct Patient Faecal Sampling with CALEX®

Patient Friendly Kits

Each kit is discretely packaged in a business style envelope with a CALEX extraction device, a patient specific instruction for use with integral label labels (including name, date of birth, NHS number, sample collection date and indicate if the sample was liquid (Y/N)) and a clear grip seal bag for return of the CALEX and the request form back to the laboratory or GP as currently with the existing stool pot method.

The IFU is written in lay terms and has guidance on taking the sample, simple to follow instructions with diagrams and a link to a video to support the correct usage of the CALEX with different sample consistencies.

Patient packs are supplied in boxes of 20 and can be stored at ambient temperature until the stated expiry date, which is generally 12-18 months, so that they can be sent out to clinics and primary care in quantities and conditions that will minimise wastage. The boxes have a dispensing tally on the front to help maintain the correct level of stock within individual locations. Hospitals can either order the kits through Alpha Laboratories and send them to clinics and primary care using their existing van delivery/sample collection services or can have the boxes sent directly to individual locations by ordering through The Alpha Portal.

Step by Step Guide for Patients

Calprotectin Stability

One of the biggest issues with calprotectin testing is the variable rates of degradation that occur within the stool sample. This is demonstrated in a stability study, in a paper published by Lasson in 2014 (Journal of Crohns & Colitis) showing individual samples to have significantly different rates of degradation. The overall conclusion from this publication, and the widely accepted premise, is that calprotectin is stable at ambient in a stool sample for three days. Within the data, however, whilst some samples are relatively stable, others lose between 30 – 50% of detectable calprotectin in that time period.

Stability within CALEX

Once the sample is in the CALEX it is stable at ambient for 7 days, giving sufficient time for the return of the sample by the patient to the laboratory. This reduces the variable degradation seen in the untreated stool samples, enabling more consistent reporting.

If the lab doesn’t want to test the CALEX immediately upon receipt, if stored at 2-8C, it is stable for 15 days.

Using the CALEX gives more consistent results and the flexibility for laboratories to follow practices that best suit their work load.

The result obtained from the patient using the CALEX, compared to sending in a stool sample into the lab for extraction will be different.

This has long been the case with use of the IBDoc calprotectin home test, for IBD positive patients, compared to the lab result. The calprotectin results are generally higher with the patient prepared sample compared to the lab prepared sample.

This is to be expected with the CALEX as well, as was shown in the article from H. Bruce et al (Annuals of Clinical Biochemistry 2023): Comparison of faecal calprotectin using two collection & extraction strategies for the BUHLMANN CALEX cap.