title: Tazobactam-induced haemolytic anaemia, possibly caused by non-immunological adsorption of IgG onto patient's red cells.
abstract: A patient with pneumonia was treated with Tazocin (piperacillin/tazobactam). However, the expected haemoglobin (Hb) increment after transfusion was not achieved. Plasma bilirubin and lactate dehydrogenase were raised. The direct antiglobulin test (DAT) was positive (4+) for immunoglobulin G (IgG) only, but no RBC antibodies were demonstrable in the plasma or an eluate from the patient's RBCs. Drug-induced haemolysis was suspected. After discontinuing Tazocin administration, Hb and bilirubin levels returned to expected values. The patient's plasma gave a positive (3+) indirect antiglobulin reaction only with RBCs pretreated with tazobactam. However, random patient plasmas also gave weak (+/- to 1+) reactions, indicating non-immunological adsorption of IgG onto RBCs rather than specific anti-tazobactam antibodies. Subsequently, plasma samples with varying IgG levels (0.8-89.7 g L(-1)) were tested against RBCs pretreated with tazobactam. The amount of plasma IgG non-immunologically adsorbed onto the drug-coated RBCs was found to correlate directly with the plasma IgG level. The patient had a high plasma IgG level (41.6 g L(-1)) which explains why the antiglobulin test was stronger with the patient's plasma than with random plasma samples. Previous reports (Garratty & Arndt, (1998) British Journal of Haematology, 100, 777-783; Arndt & Garratty (2000) Transfusion, 40, 29S) suggested that non-immunological coating of RBCs with IgG may affect RBC survival; our results would support that suggestion. This is the first reported case of haemolytic anaemia associated with tazobactam.
authors.affiliation: Transfusion Department, Southampton University Hospitals NHS Trust, Southampton, UK. richard.broadberry@suht.swest.nhs.uk
authors.forename: R E
authors.initials: RE
authors.lastname: Broadberry
authors.forename: T W
authors.initials: TW
authors.lastname: Farren
authors.forename: S V
authors.initials: SV
authors.lastname: Bevin
authors.forename: J A
authors.initials: JA
authors.lastname: Kohler
authors.forename: S
authors.initials: S
authors.lastname: Yates
authors.forename: I
authors.initials: I
authors.lastname: Skidmore
authors.forename: J
authors.initials: J
authors.lastname: Poole
authors.forename: G
authors.initials: G
authors.lastname: Garratty
mesh_terms: D000293:Adolescent; D000327:Adsorption; D000743:Anemia, Hemolytic / Q000139:chemically induced* / Q000209:etiology; D002470:Cell Survival; D003298:Coombs Test; D004912:Erythrocytes / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism*; D008297:Male; D010397:Penicillanic Acid / Q000009:adverse effects* / Q000031:analogs & derivatives*; D011014:Pneumonia / Q000150:complications / Q000188:drug therapy; D000078142:Tazobactam; D065093:beta-Lactamase Inhibitors
chemical_list: D007074:Immunoglobulin G; D065093:beta-Lactamase Inhibitors; D010397:Penicillanic Acid; D000078142:Tazobactam