Carlos Penalillo Pimentel: Detection of Rare Blood Donor Phenotypes During Investigation of Serologic Discrepancies
Carlos Penalillo Pimentel, Affiliate member of the Peruvian Association for Quality in Health, shared a post on LinkedIn:
“Immunohematology
That is why this science is exciting and takes us to totally unexpected, unsuspected and statistically unthinkable destinations.
I arrive at my Service having scheduled to study some modification to the acid elution technique so that it is not so aggressive with red blood cells, we have 3 patients with autoimmune hemolytic anemia (AHAI) and we need to ensure that the units of blood we send them are as accurate as possible in compatibility and with identical phenotype.
One proposes and God disposes, I arrive and find on the work table a strong discrepancy of globular and serum group from the routine of the previous day, I focused on solving it while controlling the 3 autoanalyzer equipment that we manage. It was solved with the enzymatic method.
We also needed to perform phenotype extended to blood units, I selected from the previous day 12 R1R1 and 12 R2R2, from all of them, we are separating those special ones that serve us in cases of incompatibilities known as Anti M, Anti s, Anti Fy a, etc.
The usual thing is to find 2 or 3 negative Fy from the group of 24, today we had 5 and with great surprise two of them were Fy null, that is to say Fya – Fyb – (the ones in the photo)
In all these years that we have been looking for donors with an uncommon phenotype, we have only managed to genotype 2.
Something incredible, we will proceed to carry out molecular biology to enter them on the Peruvian list. These donors will one day save the life of a patient with that same uncommon phenotype, that is the supreme purpose of our work area, to provide solutions in a safe and timely manner.”

Stay updated with Hemostasis Today.
-
Jun 5, 2026, 08:27Morten Thaysen Andersen: Platelet Glycobiology and The Importance of FUT8 for Platelet Function
-
Jun 5, 2026, 08:10Michael Ertl: Air Pollution and Stroke – Which Patients Are Particularly at Risk?
-
Jun 5, 2026, 07:58Omid Seidizadeh: Pleasure to Present on VWD in Aging at the ERN-EuroBloodNet Webinar Series
-
Jun 5, 2026, 07:14Elissa Embrechts: A Small But Meaningful Step Towards Better Fall Risk Prediction in Stroke Rehabilitation
-
Jun 5, 2026, 03:27Lovish Garg: Restoring Venous Flow Through Catheter-Directed Thrombus Removal
-
Jun 5, 2026, 03:20Javed Anees: Anemia in Pregnancy Is Common, but Never Trivial
-
Jun 5, 2026, 02:52Andrada Seicean: Endoscopic Ultrasound and Portal Pressure Assessment in Patients Undergoing TIPS
-
Jun 5, 2026, 02:29Sam Tomy K: Antinuclear Antibody Testing and Its Role in Autoimmune Disease Diagnosis
-
Jun 5, 2026, 01:54Abdul Mannan: What Is the Most Common “Freeloading” Medication Seen in Anticoagulated Patients?