Prophylactic Red Cell Exchange: Preventing Complications in Pregnant Patients with Sickle Cell Disease

Introduction

Management of pregnancy-related complications in patients with sickle cell disease is poorly defined. While some suggest simple transfusion, guidelines for red cell exchange (RCE) are not well described. American Society for Apheresis guidelines categorize RCE in pregnancy as category II, meaning apheresis is accepted as second-line therapy, either as a standalone treatment or with other treatments. The recent TAPS2 Trial (Transfusion Antenatally in Pregnant Women with Sickle Cell Disease) shows promising results for both better outcomes and acceptability of RCE in this patient population despite a small study cohort. Here, we present two cases of women with sickle cell disease who received prophylactic monthly RCE during pregnancy.

Methods

Both cases were prospectively followed at a large academic medical center in the United States. Data were collected as the patients presented for monthly RCE and by chart review. Complete blood count (Sysmex XN-9000) and HbS levels (agarose gel electrophoresis) were measured before and after procedures.

Results

The first patient, a 30-year-old female, G2P1, with a history of sickle cell disease (HbSS), had a previous pregnancy in Jamaica complicated by pre-eclampsia and peripartum cardiomyopathy requiring an emergent cesarian section at 7 months. Since relocating to the US, she had experienced rare pain crises and had not been transfused since her delivery six years ago. The current pregnancy was complicated by several emergency department visits for pain, prompting referral to hematology and apheresis to initiate prophylactic RCE to prevent pre-eclampsia and other sickle cell-related complications. Monthly RCE was initiated at 20w5d, and procedures were performed via bilateral ports using the Spectra Optia Apheresis System (Terumo BCT; Lakewood, CO v12) and 8 units of HbS-, C/E/K matched, crossmatch compatible red cells. A goal of less than 40% HbS was chosen due to prior pregnancy related complications in the absence of stroke. Anticoagulant Citrate Dextrose Solution USP Solution A (ACD-A) was used as anticoagulant with calcium gluconate replacement (0.4g per 500 mL exchanged). The patient underwent 5 RCEs, all except the first were performed with fetal monitoring. She tolerated all procedures well, with no signs of pre-eclampsia or cardiac compromise throughout the pregnancy and did not experience any further pain crises. Pre-procedure HbS% levels progressively decreased from 86.5% before the first exchange to 32.1% at the final exchange. Hematocrit levels remained between 27 and 30% throughout treatment. Cesarian section was performed at 38w1d (eight days after last RCE) resulting in the birth of a healthy infant weighing 3.06 kg with APGAR scores of 9 and 9. The patient has not required any transfusion or RCE postpartum.

The second patient, a 29-year-old female, G1P0, with HbS/Bthal+ sickle cell disease, had a history of retinopathy and bilateral retinal vein occlusion but had not undergone any prior red cell transfusions or exchanges. At 26 weeks of gestation, she presented with bilateral renal infarcts and transient vision loss suggestive of retinal artery occlusion. She had mildly elevated urine protein but no other signs of pre-eclampsia. The apheresis service was consulted to perform monthly RCE for the remainder of the pregnancy as prophylaxis against further vaso-occlusive events. The procedures were conducted using the same parameters as the first patient, this time with 7 units of red cells. The patient underwent 3 RCEs, experiencing only mild nausea during the first exchange and tolerating subsequent procedures well. Her initial pre-procedure HbS was 67.5%, which decreased to 40.6% before the last procedure. Hematocrit levels remained between 26 and 33%. At 37w3d (16 days after last RCE) a cesarian section was performed. A healthy infant was born weighing 3.39 kg with APGAR scores of 8 and 9. This patient has not required RCE or transfusion postpartum.

Conclusion

In conclusion, we present two cases that demonstrate the management of pregnancy-related complications in patients with sickle cell disease through prophylactic RCE. These experiences highlight the importance of individualized management strategies for high-risk sickle cell patients to ensure both maternal and fetal health along with multidisciplinary collaboration and vigilant monitoring throughout pregnancy to optimize outcomes.

No relevant conflicts of interest to declare.