Koshy R, Patel B, Harrison J S
Department of Pathology and Laboratory Medicine, NJMS/UMDNJ, University Hospital, Newark, NJ 07103, USA.
Immunohematology. 2009;25(2):44-7.
Kpa is a low-frequency antigen occurring in less than 2 percent of the Caucasian population. Mild to moderate delayed hemolytic transfusion reactions (DHTR) and hemolytic disease of the fetus and newborn attributable to anti-Kpa have been reported. Severe overt DHTR has not been reported with anti-Kpa. A case of a severe DHTR attributed to anti-Kpa after multiple RBC transfusions is being reported. A 52-year-old Caucasian woman received multiple units of RBCs for a lower gastrointestinal bleed. She was referred to our institution for hepatic and renal failure, which was supported by laboratory findings of peak LDH, bilirubin, BUN, and creatinine elevations. Hemoglobin had dropped on Day 10 after transfusion. The DAT and antibody screen (ABS) were negative. Initial workup and subsequent ABS were negative. Anti-Kpa was identified when an additional RBC panel was tested. One of the RBC units transfused was incompatible by antihuman globulin (AHG) crossmatch with the patient's plasma and typed positive for Kpa. DHTR was confirmed after extensive workup. The patient responded to supportive therapy and experienced an uneventful recovery. DHTR may not be considered when DAT and ABS are negative. However, correlation of recent transfusion with signs and symptoms should alert the clinician to entertain and investigate a DHTR that should include the AHG crossmatch of all implicated RBC units. The severity of the reaction also raises concerns as to when and what antigen specificity should be considered for inclusion in the antibody screening cells.
Kpa是一种低频抗原，在不到2%的白种人群中出现。已有报告称，抗Kpa可导致轻度至中度迟发性溶血性输血反应（DHTR）以及胎儿和新生儿溶血病。尚未有抗Kpa导致严重明显的DHTR的报告。本文报告了一例多次输注红细胞后由抗Kpa引起的严重DHTR病例。一名52岁的白种女性因下消化道出血接受了多次红细胞输注。她因肝肾功能衰竭被转诊至我院，实验室检查结果显示乳酸脱氢酶、胆红素、血尿素氮和肌酐峰值升高，支持了这一诊断。输血后第10天血红蛋白下降。直接抗球蛋白试验（DAT）和抗体筛查（ABS）均为阴性。初始检查及随后的ABS检查均为阴性。当检测额外的红细胞谱时，发现了抗Kpa。输注的其中一个红细胞单位与患者血浆进行抗人球蛋白（AHG）交叉配血不相合，且Kpa分型呈阳性。经过广泛检查后确诊为DHTR。患者接受支持性治疗后恢复顺利。当DAT和ABS为阴性时，可能不会考虑DHTR。然而，近期输血与体征和症状之间的关联应提醒临床医生考虑并调查DHTR，这应包括对所有相关红细胞单位进行AHG交叉配血。该反应的严重程度也引发了关于何时以及应考虑将何种抗原特异性纳入抗体筛查细胞的担忧。
