Differential diagnosis of feline small cell lymphoma (SCL) from inflammatory bowel disease (IBD) is a challenge for veterinary specialists.1,2 Accurate diagnosis is essential for the proper treatment and improved prognosis of cats with chronic enteropathy.3,4 Both ailments result in similar clinical presentations often requiring veterinarians to obtain biopsy specimens for histopathological assessments and additional molecular testing. While histopathological evaluations of hematoxylin and eosin (H&E) staining are considered a standard procedure, in many cases, pathologists cannot confidently yield a differential diagnosis.1,5 Many pathologists rely on data from additional molecular tests such as immunohistochemistry (IHC) for immunophenotyping and PCR for Antigen Receptor Rearrangements (PARR) for clonality analysis to provide diagnostic clarity on challenging biopsies.1,5 However, the low overall accuracy of these secondary tests limits their utility in disease differentiation.1,2,6,7,8,9
Due to the limitations of current secondary tests, LymphoPro Feline Dx was designed to provide veterinarians with actionable intelligence for more accurate differential diagnosis of SCL and IBD. Based on artificial intelligence and machine learning algorithms, the LymphoPro Feline Dx test assesses the active state of the lymphocyte populations in the gastrointestinal tract, resulting in a numerical score that objectively classifies specimens as likely IBD, indeterminant, or SCL.
LymphoPro Feline Dx has been validated for feline duodenal biopsies that were considered to be either SCL or IBD. Algorithm training was performed with 39 specimens, composed of 22 SCL and 17 IBD cases. Algorithm validation was performed with an independent cohort of 54 specimens, composed of 30 SCL and 24 IBD cases, and resulted in a sensitivity of 86.7% and specificity of 91.7%. An indeterminant rate of 3.7% was observed among specimens analyzed. For the purposes of determining sensitivity and specificity, indeterminant specimens were included in the calculations.
Specimens used for both algorithm training and validation were reviewed by a panel of five (5) to seven (7) expert veterinary specialists, including pathologists, oncologists, and internists. Only specimens that received a consensus diagnosis were included in the algorithm training and validation. For each case, panel diagnosis was based on clinical presentation, histopathological evaluation, and IHC results. PARR was ordered for each case, and in the cases where PARR could be performed, this data was incorporated into the panel review. Attempts were made to obtain the clinical outcome for each case, and, when available, this outcome data was assessed to further confirm the diagnosis.
New River VDL will provide a test kit for each patient’s tissue specimen. Veterinarians can order test kits online, and test kit orders are usually processed the same day and received by the veterinarian within approximately three (3) business days.
The LymphoPro Feline Dx test can be ordered by filling out and submitting the Test Requisition Form with the test kit. Pathology reports and any molecular test results should also be submitted with the test kit.
After following the Test Kit Instructions, the veterinarian will send the completed test kit, including three (3) serial FFPE tissue sections or one (1) FFPE tissue block, to New River VDL for analysis at its clinical reference laboratory.
Within approximately five (5) business days of test kit receipt, LymphoPro Feline Dx testing will be completed and a score will be generated that classifies the specimen as likely IBD, indeterminant, or SCL.
New River VDL will email or fax the LymphoPro Feline Dx test results to the veterinarian.
LymphoPro Feline Dx proteomic data are statistically analyzed with a validated algorithm to yield a numerical score, ranging from -10 to +10, that classifies the patient specimen as likely IBD, indeterminant, or SCL. Results are reported to the veterinarian via either email or fax, as specified by the veterinarian. Veterinarians can easily review and interpret the LymphoPro Feline Dx results and, in conjunction with histopathological data, clinical examinations, and other relevant findings, render a final diagnosis.