ABSTRACT
BACKGROUND: Hemolysis following the administration of intravenous immunoglobulin (IVIG) is an important adverse event (AE). While the monocyte monolayer assay (MMA) has been used to predict in vivo hemolysis when serologically incompatible blood may be transfused, it has also been shown to correlate with IVIG-associated hemolysis. In this study, the MMA was examined for its utility in assessing the risk of hemolysis after IVIG. STUDY DESIGN AND METHODS: Forty-two non-blood group O patients receiving high-dose IVIG (≥2 g/kg) were examined using an autologous and allogeneic MMA. Hemolysis was defined by a drop in hemoglobin of ≥1 g/L, a positive direct antiglobulin test (DAT) and eluate, and a decrease in haptoglobin or increase in lactate dehydrogenase and/or reticulocytes. RESULTS: Forty-two patients provided 50 assessable postinfusion samples, with hemolysis observed in 20 (40%) of cases. Autologous MMA using post-IVIG red blood cells significantly correlated with clinical outcomes when compared to allogeneic MMA (P = .0320 vs .5806, t test). No significant difference in receiver operating characteristics was observed when comparing autologous MMA testing against DAT for the diagnosis of IVIG-associated hemolysis. However, when using samples collected 5 to 10 days after receipt of high-dose IVIG, the autologous MMA had higher sensitivity than the DAT. CONCLUSION: MMA testing with autologous monocytes collected 5 to 10 days after receipt of high-dose IVIG can be used for the diagnosis of IVIG-associated hemolysis and may be of particular value in cases in which the Day 5 to 10 DAT is negative.
Subject(s)
Hematologic Tests , Hemolysis/drug effects , Immunoglobulins, Intravenous/adverse effects , Monocytes/metabolism , Adult , Humans , Immunoglobulins, Intravenous/administration & dosage , MaleSubject(s)
ABO Blood-Group System/immunology , Hemolysis/drug effects , Hemolysis/immunology , Immunoglobulins, Intravenous/adverse effects , Receptors, Fc/metabolism , Adult , Aged , Aged, 80 and over , Blood Group Incompatibility , Child , Female , Hematologic Tests , Humans , Male , Middle Aged , Prospective Studies , Risk Factors , Young AdultABSTRACT
BACKGROUND: Various versions of the monocyte monolayer assay (MMA) have been used to assess clinical significance of red blood cell (RBC) alloantibodies in transfusion for more than 35 years. However, the optimal conditions, including anticoagulant used for whole blood samples, temperature and duration of storage, and optimal pH for assessing the response of monocytes to antibody-bound RBCs, have never been clearly delineated. STUDY DESIGN AND METHODS: Whole blood from healthy donors was collected in ACD, EDTA, or heparin and stored at room temperature (RT) versus 4°C for up to 2 days. pH was examined with and without buffers. Phagocytosis of anti-D-opsonized R2 R2 RBCs was used as the positive control for comparison studies. Whole blood was taken into ACD and kept at RT until testing, from patients with or without immune hemolytic anemia. RESULTS: No significant differences in the phagocytosis of the R2 R2 control RBCs were observed using ACD anticoagulant between freshly drawn or up to 36-hour-stored whole blood kept at RT, regardless of the donor. Physiologic pH during MMA was important for optimal monocyte interactions with antibody-opsonized RBCs. MMA results with patient samples, under optimal conditions, kept up to 30 hours in one instance of long-distance shipment, correlated with clinical hemolysis. CONCLUSION: MMA can be reliably performed on whole blood samples drawn into ACD and kept at RT for up to 36 hours and when physiologic pH is maintained during the assay. Future studies are required to confirm whether use of these conditions with patient monocytes can provide accurate determination of alloantibody significance in patients requiring blood transfusion.
