You’re probably familiar with using the Spectra Optia™ Apheresis System for red blood cell exchange (RBCX) and therapeutic plasma exchange (TPE). You may also have learned about using the device for continuous mononuclear cell (CMNC) collections in our December 2024 issue. 

But you may not know about four additional protocols you can perform with Spectra Optia that can help you give targeted care to even more patients. In this article, you’ll get an overview of those protocols: mononuclear cell collection (MNC), granulocyte collection (also known as polymorphonuclear cell collection [PMN]), bone marrow processing (BMP), and white blood cell depletion (WBCD).

Mononuclear cell collection

MNC was the first collection protocol released on Spectra Optia. It collects the same types of cells as CMNC, including monocytes, lymphocytes, CD34+ cells, and dendritic cells.

MNC is more automated than CMNC and can be considered more complex. It uses the standard filler — the same one used for exchange procedures — and the Collect Set with the teal-colored cover. 

Target cells are collected in two sequential phases, which will likely occur several times over a procedure.
Phase 1: Cells are pumped from the channel into a secondary chamber.
Phase 2: When the chamber is full, the contents are automatically flushed into the collection bag.
This process repeats until run targets are attained.

Polymorphonuclear cell collection

The PMN procedure is also known as granulocyte collection. PMN cells from healthy donors can be used for granulocyte transfusions, which can help prevent or control otherwise fatal infections in cases of neutropenia (lack of granulocytes), PMN dysfunction, or severe ongoing infection.

PMN is a continuous collection procedure similar to CMNC. Like CMNC, PMN also uses the Spectra Optia™ IDL Set and IDL filler. However, PMN can use a sedimenting agent such as hydroxyethyl starch (HES) mixed with trisodium citrate as the anticoagulant. During the procedure, you can monitor and adjust the depth at which the cells are collected within the buffy coat layer based on the desired hematocrit of the collected product.

Bone marrow processing

When hematopoietic stem cells (HSCs) are collected directly from a patient’s or donor’s bone marrow, the BMP procedure is necessary to decrease product volume and remove unwanted cells prior to infusion.

During this continuous collection procedure, target MNCs flow into the collection bag while all other components are returned to the BMP accessory bag, which contains the starting marrow product.

This is the only Spectra Optia protocol in which the device is not connected to a patient or donor. While the IDL Set is used with the IDL filler in the CMNC and PMN protocols, BMP pairs the IDL Set with the standard filler, plus the Spectra Optia™ BMP Accessory Set.

White blood cell depletion

The WBCD protocol is another continuous collection procedure similar to CMNC, designed to reduce the leukocyte concentration in a patient's peripheral blood. It is used for patients with leukocytosis (excess white blood cells) who are at risk of leukostasis. It is often seen in myeloproliferative disorders and leukemias.

During WBCD, target cells flow into the collection bag while other blood components are returned to the patient. The volumes collected will most likely be much higher than with CMNC due to the patient's significantly higher white blood cell count and a higher collect pump flow rate.

The WBCD protocol uses the IDL Set and IDL filler.

Protocol options for optimal patient care

These four procedures join RBCX, TPE, and CMNC as protocols offered on the Spectra Optia system, giving you flexibility to help treat a range of patient needs and provide more care to more people. For details about performing any of these protocols, see your Spectra Optia Apheresis System Operator's Manual or talk with your Terumo Blood and Cell Technologies representative.

Sources:
McLeod BC, Weinstein R, Winters JL, Szczepiorkowksi SM, eds. Apheresis Principles and Practice. 3^rd ed. Bethesda, MD: AABB Press; 2010:254.
Terumo Blood and Cell Technologies. Spectra Optia Apheresis System: Operator's Manual. 2025. Part no. PL-0049