AABB News: New Red Cell Exchange Program in Zambia Reduces Sickle Cell Crises

This article originally appeared in AABB News, a benefit of AABB membership. Join AABB today to read the rest of this month’s issue.

Every year on June 19, countries throughout the world celebrate World Sickle Cell Day to raise awareness of the genetic blood disorder and to highlight the challenges and experiences of people with sickle cell disease (SCD), which impacts approximately 100,000 Americans and more than 20 million people worldwide.¹

In honor of World Sickle Cell Day, AABB News is pleased to highlight AABB’s efforts to reduce the burden of SCD in Zambia through the establishment of an Ultraviolet Pathogen Reduction Technology (UV-PRT) Therapeutic Red Cell Exchange program. The UV-PRT program, funded by Sandia National Laboratories (SNL) and the Office of Radiological Security (ORS) of the U.S. Department of Energy, was implemented under IRB through the Zambia National Health Research Authority.

In 2022, AABB, under the direction of Christine Bales, AABB vice president of consulting and global services, collaborated with the Zambia National Blood Transfusion Service (ZNBTS) and Commonwealth Transfusion Foundation (CTF) to implement the project in Lusaka, Zambia, using UVPRT as a potential blood processing technology and a substitute for blood irradiation to reduce the risk of transfusion-associated graft versus host disease (TAGVHD).

The project focused on three patient cohorts from July 2022 to March 2023: patients with SCD, oncology patients and neonate patients. Diane de Coning, BSc, AABB global services consultant and program director for Africa, noted that the patients in the SCD cohort were impacted most significantly by the project. It’s where the actual blood product was most needed, she said.

“There are so many patients with SCD in Zambia, and the children seemed to need the red blood cell transfusion exchange more than anything,” De Coning told AABB News. “We started off in the children’s unit at the University Teaching Hospital in Lusaka. Due to popular demand, we were approached by the University’s adult hematology department to include adult patients in the SCD project as well.”

The objective of the red cell exchange (RCE) procedure was to reduce the patient’s sickle cell hemoglobin (HbS) level to below 30%, maintain the Hb level of not more than 10-11g/dl to avoid viscosity, and decrease symptoms and complications associated with SCD. The ZNBTS installed the Terumo BCT automated blood processor and Mirasol pathogen reduction technology system. Nurses and clinicians underwent training on the signs and symptoms of transfusion reactions, specifically TA-GVHD in patients, and the ZNBTS Apheresis Team learned the technical aspects of apheresis platelet collection.

Patient physicians performed thorough clinical assessments and laboratory investigations before each RCE procedure, which included evaluating patients’ Hb electrophoresis (HbS level less than 30% were excluded); hemoglobin and hematocrit; liver functions; and electrolytes. Good IV access was also required.

“The latter proved to be quite a challenge for us, but as the procedures became more frequent, the staff became better at accessing IV lines for the RCE,” De Coning pointed out. “We discovered we needed five units maximum of blood for the exchange.”

Impact and Recovery

SCD is most common globally in sub-Saharan Africa, where up to 45% of sub-Saharan Africans are carriers of the disorder. According to the Zambian Network for Sickle Cell-Amplified Voices and Advocacy, there are more than 16,000 sickle cell patients on record – the majority younger than the ageof 15 years – across the University Teaching Hospitals and Arthur Davison Children’s hematology clinic in Zambia.² In 2021, the Zambian Ministry of Health recognized sickle cell disease as a public health crisis due to the rising test positivity and mortality rates.³

“SCD has all sorts of complications, including pain and acute chest syndrome. We were using simple transfusions to treat patients before the project. This is the first time we performed the RCE procedure in the country,” stated Joseph Mulenga, MD, ZNBTS medical director and principal investigator. “It took a little bit of learning, but the equipment is very easy to use. It’s an innovation for Zambia that’s never been done before. It has been welcomed by our physicians, patients and the general population. They can see the difference in the patient’s health.” Both De Coning and Mulenga witnessed patients’ speedy recoveries throughout the UV-PRT project and lauded the program’s impact on Zambians with SCD.

“There was a 16-year-old girl I saw before the RCE who couldn’t even walk because she was so weak and ill, and then she was up and about the next day. It was a miraculous recovery,” De Coning recounted. “The results were unbelievable. The feedback from the clinicians and nurses was phenomenal. They couldn’t believe the recovery rate amongst the patients who received RCE.”

Mulenga recalled the miraculous recovery of an extremely ill pregnant woman in the sickle cell cohort with a low hemoglobin level. The baby, he said, initially had a low prognosis. The patient underwent the RCE procedure and gave birth to a healthy baby girl the following day.

“It was our first time performing an RCE transfusion in a pregnant woman,” Mulenga told AABB News. “She reported the baby moving during the exchange. It was a very successful delivery and a special case.”

Mulenga noted a drastic reduction in sickle cell crises since the program’s implementation at UTH.

“We’ve seen the dramatic impact it’s had on treating complications of SCD. Patients have gone from a very dire situation to smiling after the procedure. We haven’t seen any repeat patients after their transfusion, whereas in the past, they would come back for a blood transfusion every so often due to a drop in blood levels. The patients who have undergone the RCE procedure have gone on to live normal lives.”

Dia Phiri, ZNBTS donor manager, described the RCE procedure as “life-changing” for patients, noting their ages ranged from three to 30 years old. “It’s such a fine moment for those of us operating machines to see patients transform from being visibly in pain before we start the procedure to all smiles and happiness after the procedure. It gave us a lot of satisfaction as operators.”

Phiri also discovered an increase in patients’ activity levels after the procedure. “When we pay patients follow-up visits after their procedure, we can see they are not the same anymore. It’s been good for them. We still look forward to seeing more patients benefit from this procedure,” Phiri said.

Standard of Practice

De Coning told AABB News the sickle cell community in Zambia has heard the RCE procedure is helping patients and lengthening the time between regular transfusions tremendously. Although the pilot study ended in March, the UV-PRT Therapeutic Red Cell Exchange program is still going strong in Zambia. In addition, De Coning noted that sickle cell trait screening – which was introduced as part of the project – has now become a standard of practice.

“They were not doing this screening before, and the units were being transfused to the patient,” she said. “We tested every unit collected that goes to patients with SCD for the trait. If the unit tested positive, we issued it to another patient. We only used sickle cell trait negative blood for the RCE transfusions.”

Looking ahead, De Coning hopes more funding becomes available to expand the program to all 10 provinces in Zambia. That is my dream, she added. “As you go North in Zambia, sickle cell becomes more prominent amongst the community,” De Coning said. “We want to go where the problem really is, and it is quite expensive and difficult for Zambians to travel to Lusaka for treatment. We want to ensure patients with SCD are getting treatment there.”

Mulenga stated the Zambian Ministry of Health recently wrote a memo to inform all delegates in the country to direct patients with SCD to Lusaka for a RCE transfusion.

“It is just limited to our facility because that is where the equipment and experts are at the moment,” Mulenga explained. “We are planning to roll out the program to the entire country. We’ve mapped out sickle cell in Zambia. We have seen higher HbS levels in some areas, and those are the areas we are going to target first until we can cover the whole country and make it a standard of practice as far as management of SCD is concerned.”

REFERENCES
1. U.S. Department of Health and Human Services. What is sickle cell disease? National Heart Lung and Blood Institute. https://www. nhlbi.nih.gov/health/sickle-cell-disease
2. Sickle cell disease. (2022). Zambia Sickle Cell Networks. https:// zambiansicklecellnetworks.org/sickle-cell-disease/
3. Thelwell, K. (2022). Screening for sickle cell disease in Zambia. The Borgen Project. https://borgenproject.org/sickle-cell-diseasein-zambia/