(P-IG-6) Anti-Era Antibody In The Context Of Warm Autoimmune Hemolytic Anemia, Renal Failure And Extensive Comorbidities: A Complex Case Study

Er^a antigen is highly prevalent with exceedingly rare corresponding antibody leaving its clinical impact largely unexplored. Reports suggest that Anti-Er^a may reduce RBC survival, but no cases of hemolytic transfusion reactions (HTR) or hemolytic disease of the fetus and newborn (HDFN) have been reported. Here, we present a patient with known anti-Era who is suspected of experiencing HTR associated with transfusion of least incompatible Er^a positive blood.

Study

Design/Methods:

A Caucasian woman in her early fifties with known HIV, systemic lupus erythematosus, end-stage renal disease, vascular dementia, hypothyroidism, and warm autoimmune hemolytic anemia (WAHA) presented with severe nosebleed and critically low hemoglobin (HB) levels. Initial tests indicated a Hb of 4.4 g/dl and hematocrit (HCT) of 13.9%, among other findings. She had a history of anti-D, anti-K, HTLA, warm auto antibody and anti-Er^a. Currently, she tested positive for Anti-Era without detection of previously antibodies. 

She received least incompatible red cell units leading to a temporary improvement of Hb/ HCT but platelets continued to decline (Table 1A). Within a day, Hb/HCT dropped, for which another unit of RBC was transfused. HTR was suspected indicated by further decline in Hb/HCT, undetectable haptoglobin, elevated lactate dehydrogenase (LDH) and bilirubin. However, the pre-transfusion hemolysis work-up was not available for comparison. No other symptoms or change in the vital signs, supportive of HTR were noted (Table 1B). Further work-up revealed no hemolysis in the post-transfusion sample, no issues with clerical check, no discrepancy in ABORH type. The DAT polyspecific and IgG were positive and C3d was negative. The eluate was negative. Peripheral blood smear demonstrated leukocytopenia, marked normocytic anemia and occasional spherocytes. A bone marrow biopsy revealed mildly hypo-cellular marrow. Over subsequent days, laboratory values remained largely unchanged, though renal function tests showed gradual improvement with ongoing dialysis and antiretroviral therapy.

Results/Findings:

Despite multiple interventions, the patient's condition showed minimal improvement. On day 16 of admission, the patient was started on steroids. There was gradual improvement of  Hb and platelets (Table 1A). The patient was discharged on day 36 with a tapered dose of steroids.  

Conclusions:

This case underscores the challenges in managing patients with rare antibodies like anti-Er^a compounded by multiple comorbidities. The complex interplay of her comorbidities, epistaxis due to uremic platelet dysfunction, and superimposed WAHA likely exacerbated her chronic anemia, making an HTR due to anti-Era less probable. Diagnosing HTRs in such complex cases requires a thorough evaluation and a cautious approach to transfusion strategies. It is essential to consider the overall clinical context rather than focusing on a single presumed cause.