(P-TS-26) Case Report of Possible Reverse TRALI

Background/Case Studies: Cases of Transfusion-Related Acute Lung Injury (TRALI) continue to be an important cause of transfusion-related fatalities, representing 16% of fatalities reported to the FDA in 2021. Most TRALI cases are related to donor antibodies that match a patient’s antigen within the HLA or HNA systems. Very few are attributed to patient antibodies that match a donor’s antigen (so-called “Reverse TRALI”). This is a report of a possible case of reverse TRALI. On 11/30/2024, a G5P2 female with history of prior transfusion was admitted for a repeat c-section at 38 weeks. Approximately 4 hours later the patient became hypotensive, was taken back to surgery and uterine hematoma was discovered. Post-surgery, the patient’s hemoglobin dropped from 10.9 g/dL to 7.3 g/dL and was transfused 2 units of apheresis plasma and 2 units of packed red blood cells (RBC) sequentially over 4 hours. After the first RBC unit (third in sequence), the patient became dyspneic with O₂ saturation of 88% on nasal cannula flow rate 2. The patient’s blood pressure dropped slightly from 107/73 to 99/70 but she remained afebrile. Chest x-ray at time of reaction showed low lung volumes, with minimal right basilar subsegmental infiltrates. Patient required increased oxygen flow rate to 6 by nasal cannula over the next several hours. Symptoms did not improve with lasix. Chest x-ray 2 days later showed bibasilar infiltrates and worsening small effusions but by day 10 showed clear lung fields.

Study

Design/Methods: All four implicated donors were male with no history of transfusion or transplant. Based on the patient’s history of transfusion and multiple pregnancies, reverse TRALI was suspected. Patient HLA and HNA antibody testing and donor HLA antigen testing were performed by an outside reference laboratory.

Results/Findings: The patient was negative for HNA antibodies but had multiple HLA Class I and II antibodies. Table 1 shows the patient’s HLA antibodies along with donor HLA antigen typing. Three of the four donors show antigen/antibody matches with the patient (highlighted in bold).

	PATIENT	PLASMA DONOR #1	PLASMA DONOR #2	RBC DONOR #1	RBC DONOR #2
HLA Class I Antibodies	Anti-C14,18 Anti-Cw1,w4,w9,w10
HLA Class I Antigens		A*02,66 B*14,35 Bw6 C*04,08 Cw4,w8	A*01,68 B*15,57 Bw4,w6 C*03,18 Cw10	A*02,03 B*14,39 Bw6 C*07,08 Cw7,w8	A*24,30 B*07,13 Bw4,26 C*06,07 Cw6,w7
HLA Class II Antibodies	Anti-DRB1:4,11
HLA Class II Antigens		DRB1*01,08	DRB1*04,13	DRB1*04	DRB1*07,13

Conclusions: We believe this represents a case of reverse TRALI with the second plasma unit and first RBC unit being the likely culprits. This case highlights the need to consider reverse TRALI when faced with a clinical situation consistent with TRALI but where the donors do not have a risk profile consistent with forming HLA or HNA antibodies.