Regina M. Leger

Serology of antibodies to second‐ and third‐generation cephalosporins associated with immune hemolytic anemia and/or positive direct antiglobulin tests

BACKGROUND: First‐generation cephalosporins rarely caused immune hemolytic anemia (IHA). Second‐ and third‐generation cephalosporins, especially cefotetan and ceftriaxone, are increasingly associated with severe, sometimes fatal IHA.

Serological studies of piperacillin antibodies.

BACKGROUND: Penicillin‐induced immune hemolytic anemia (IHA) is associated with immunoglobulin G antipenicillin detected by testing penicillin‐coated red blood cells (RBCs). Antibodies to piperacillin, a semisynthetic penicillin, would be expected to react similarly; however, antipiperacillin can be detected by testing in the presence of the drug. Piperacillin is commonly used in combination with tazobactam, which causes nonimmunologic protein adsorption onto RBCs. In six cases of piperacillin‐induced IHA, reactivity with piperacillin‐coated RBCs was not similar to reactivity of antipenicillin with penicillin‐coated RBCs.

Severe immune hemolytic anemia associated with prophylactic use of cefotetan in obstetric and gynecologic procedures

Second- and third-generation cephalosporins, especially cefotetan, are increasingly associated with severe, sometimes fatal immune hemolytic anemia. We noticed that 10 of our 35 cases of cefotetan-induced hemolytic anemias were in patients who had received cefotetan prophylactically for obstetric and gynecologic procedures. Eight of these cases of severe immune hemolytic anemia are described.

Piperacillin-induced immune hemolytic anemia in an adult with cystic fibrosis.

We report a case of drug-induced immune hemolytic anemia (DIIHA) in an adult female with cystic fibrosis (CF), complicating routine treatment of a pulmonary exacerbation with intravenous piperacillin-tazobactam. Workup revealed a positive direct antiglobulin test (DAT) due to red blood cell (RBC)-bound IgG and C3 and piperacillin antibodies detectable in the patients serum. The potential influence of CF transmembrane conductance regulator mutations on the severity of DIIHA is discussed. This report illustrates the importance of early identification of DIIHA, a rare complication of a commonly utilized medication in CF.

Serologic characteristics of ceftriaxone antibodies in 25 patients with drug-induced immune hemolytic anemia (CME)

BACKGROUND: Ceftriaxone, a third‐generation cephalosporin, is commonly used to prevent and treat infections. Since 1987, it has been the second most common cause of drug‐induced immune hemolytic anemia (DIIHA) investigated in our laboratory.

False‐positive eluate reactivity due to the low‐ionic wash solution used with commercial acid‐elution kits

BACKGROUND: During the use of commercial red cell (RBC) acid‐elution kits for adsorption and elution (adsorption/elution) studies with anti‐ D, unexpected reactive eluates (anti‐D) were obtained from D‐ RBCs. Such results were not obtained with a parallel xylene method or, historically, with heat and ether methods.

Positive direct antiglobulin tests and haemolytic anaemia following therapy with the beta-lactamase inhibitor, tazobactam, may also be associated with non-immunologic adsorption of protein onto red blood cells.

In 1998, we reported [1] that the beta-lactamase inhibitors, sulbactam and clavulanate (constituents of Unasyn [Pfizer, New York, NY] and Timentin [GlaxoSmithKline, Pittsburgh, PA], respectively) seem to affect the red blood cell (RBC) membrane so that proteins are non-specifically adsorbed. This non-specific protein adsorption can cause positive antiglobulin tests when testing RBCs that have been exposed to the drugs both in vitro and/or in vivo [1–3]. None of the patients studied by Williams et al . [2] or Lutz & Dzik [3] with a positive direct antiglobulin test (DAT) due to clavulanate or Unasyn (sulbactam) had signs of haemolytic anaemia (HA). We reported a temporal relationship between drug administration and HA in three patients (one taking Unasyn and two taking Timentin) [1]. We suggested that if the positive DATs in these patients were caused by nonspecific adsorption of protein, then non-specific uptake of protein onto RBCs in vivo may sometimes lead to decreased RBC survival. This hypothesis was supported by studies with sulbactamand clavulanate-treated RBCs, following incubation with normal plasma in vitro , using a monocyte monolayer assay (MMA) known to predict decreased RBC survival in vivo ; treated RBCs showed increased reactivity with monocytes [4]. Another beta-lactam inhibitor, tazobactam (found in combination with piperacillin in Tazocin [Wyeth, Philadelphia, PA] and Zosyn [Wyeth]) can be added to this group, as it also seems to affect the RBC membrane so that proteins are nonspecifically adsorbed. When RBCs treated with tazobactam (Wyeth; 40 mg/ml in barbital buffer, pH 9·8) are incubated with normal plasma for two hours, they react strongly (3+) with anti-IgG, anti-C3 and anti-albumin and by the MMA [4]. Broadberry et al . [5] recently reported a case of HA in a patient taking Tazocin. The patient’s RBCs had a strongly positive DAT and the patient’s serum reacted strongly with tazobactam-treated RBCs. Normal plasma/sera also reacted with tazobactam-treated RBCs, due to non-specific uptake of proteins (i.e. anti-albumin was reactive). In the past three years, we have investigated samples from seven patients (and have anecdotal reports of three more) who were suspected to have immune HA due to Zosyn. All seven patients’ RBCs had a positive DAT. Three of the seven patients had antibodies to piperacillin (one was recently reported in this journal [6]). Two of the most recent patients’ RBCs were tested and found to be reactive with anti-albumin, thus confirming non-specific uptake of protein. These cases, and the cases mentioned above, add support to the suggestion that non-immunologic adsorption of protein onto RBCs by beta-lactam inhibitors may be associated with HA. The MMA results suggest that non-specifically bound IgG, and perhaps complement (present in beta-globulins), can interact with monocyte/macrophage receptors.

Weakening or loss of antibody reactivity after prewarm technique

BACKGROUND:  The prewarm (PW) technique is a popular approach to determine whether cold antibodies are reacting at 37°C or to detect potentially clinically significant antibodies in the presence of cold autoantibodies. The PW technique has been criticized because of unexpected loss of antibody reactivity and inappropriate use of the method.

A negative or very weakly positive DAT should not exclude investigation of drug‐induced immune hemolytic anemia

Wallace 1 makes some interesting observations in his editorial “Monitoring the nation’s blood supply,” particularly the purpose of a national monitoring system, the location of data reporting, and the use of an effective information system covering all blood centers. In April 2001, the National Blood Service (NBS) of England and North Wales and the hospitals it supplies set up a national system for monitoring the blood supply, 2 the Blood Stocks Management Scheme (BSMS). Data collection centers on a structured query language (SQL) database, in which various data are stored on issues, inventory, wastage, and shelf life. Data are entered into the database either through downloads from computer systems or through manual data entry via the BSMS website (http:// www.bloodstocks.co.uk). The Web deployment of this system gives flexibility in terms of multiuser access for the input and extraction of data and information. Using the Web, standard reports can be generated automatically from the data in real time, allowing tactical use of the information on a day-to-day basis. Participating hospitals and all blood centers can access real-time graphic displays of wastage, shelf life of stock, and the number of days’ worth of stock held. Graphs show the average of individual hospitals, and all participants and the data are anonymized. Participants also have the opportunity to benchmark performance against other users, for example, against those with similar blood usage. These graphical displays act as a driver for change because hospitals and blood centers can compare their performance to their peers. All 14 NBS centers participate in the BSMS, and hospital participation is voluntary. As of March 2003, 74 percent of hospitals with direct issues from the NBS were registered. The hospitals cover all categories, from large teaching hospitals to small community and private hospitals, and account for 82 percent of NBS issues. From the outset it was decided that the BSMS would act not only as a monitoring system but also as a driver for improvement in blood inventory management both within the hospitals and within the NBS and as a means of promoting better understanding of inventory management. Data can be extracted easily from SQL format to most commercial analysis software. This access enables analysis of data down to individual hospital and blood center level and the investigation of trends and patterns for use in strategic decision making. A recent survey of participants indicated that 89 percent of hospital registrants found participation useful. Many have made changes in inventory management practice through participation in the BSMS, including reducing inventory levels, altering management of satellite fridges, introducing stock rotation, and introducing stock management training. The NBS has made changes in practice including improving stock rotation. The BSMS has also increased the awareness of the relationship between inventory level, age of blood at issue, and outdated units. The BSMS goes a long way to addressing the observations highlighted in the editorial. Though still in its infancy, it has generated much information in 2 years on hospital demand, RBC inventories, and RBC wastage in both the NBS and the hospitals and has for the first time enabled integration of blood center and hospital stock management. It has been a valuable resource for inventory monitoring and strategic planning and a driver for change in practice. Data collection for PLTs was added in April 2003. Future developments include electronic data information exchange between the database and hospitals. Judith Chapman, FIBMS, MBA e-mail: judith.chapman@nbs.nhs.uk Robert Hick, BSc Blood Stocks Management Scheme PO Box 33910 London NW9 5YH, UK

Antibodies to oxaliplatin, a chemotherapeutic, are found in plasma of healthy blood donors.

BACKGROUND: Oxaliplatin is one of the platinum chemotherapeutics that includes cisplatin and carboplatin. Antibodies to all three drugs have caused immune hemolytic anemia (IHA). In an investigation of oxaliplatin‐induced IHA, the negative plasma control agglutinated oxaliplatin‐coated red blood cells (RBCs). Previous preparations of this control had not agglutinated oxaliplatin‐ or cisplatin‐coated RBCs.