Immune complex-mediated haemolytic anaemia and Evans syndrome induced by diclofenac

Case Report: Oral Cimetidine Administration Causes Drug-Induced Immune Hemolytic Anemia by Eliciting the Production of Cimetidine-Dependent Antibodies and Drug-Independent Non-specific Antibodies

Previously, it was reported that multiple patients had hemolytic anemia associated with cimetidine administration, while only one patient who had received intravenous cimetidine was serologically diagnosed with drug-induced immune hemolytic anemia (DIIHA) caused by cimetidine-dependent antibodies. However, the ability of oral cimetidine intake to induce the production of antibodies has not been examined. In this study, we report a 44-year-old male patient in whom oral cimetidine administration resulted in cimetidine-dependent antibodies and drug-independent non-specific antibodies, leading to the development of DIIHA. Serological tests showed that the results of direct antiglobulin test (DAT) for anti-IgG (3+) and anti-C3d (1+) were positive. The IgM and IgG cimetidine-dependent antibodies (the highest total titer reached 4,096) were detected in the plasma incubated with O-type RBCs and 1 mg/mL cimetidine or the plasma incubated with cimetidine-coated RBCs. IgG-type drug-independent non-specific antibodies were detected in blood samples collected at days 13, 34, 41, and 82 post-drug intake. This is the first study to report that oral administration of cimetidine can elicit the production of cimetidine-dependent antibodies, leading to DIIHA, and the production of drug-independent non-specific antibodies, resulting in hemolytic anemia independent of cimetidine. Presence of pathogenic antibodies were detectable longer than 41 days. This suggests that patients with DIIHA caused by cimetidine need to be given necessary medical monitoring within 41 days after cimetidine intake.

Drugs and autoimmunity--a contemporary review and mechanistic approach

Drug-induced autoimmunity is an idiosyncratic, non-IgE immune related drug reaction. Interestingly, although many drugs have been reported to induce autoantibodies, only a few have a definitive association with drug-induced autoimmune disease. The prototype disease is drug-induced lupus and the typical drug for drug-induced lupus is minocycline. The production of autoantibodies and the induction of symptoms in drug-induced lupus results from a variety of mechanisms, which can include suppression of central or peripheral tolerance, alteration of gene transcription in T and B cells, abnormal cytokine and/or cytokine receptor balance and function, chromatin structure modification and antigen modification. Multiple mechanisms may apply for different drugs, and understanding the pharmacological actions of these agents helps us decipher the etiology. For example, DNA hypomethylation may occur with hydralazine, which leads to increased transcription, increased LFA-1, the generation of autoreactive T cells and a breakdown in peripheral tolerance. Frequently, more than one pathway may be involved. Interestingly, most patients with newly formed autoantibodies resulting from drugs do not develop clinical disease. Nonetheless, the explosion in the use of biological modifiers has been associated with production of autoantibodies, an observation that illustrates the complex nature of these interactions, in that these agents are frequently used to treat autoimmunity, yet may produce autoimmune diseases themselves.

Massive haemolysis after intramuscular diclofenac in a patient who apparently tolerated oral medication

BACKGROUND AND OBJECTIVES

Administration of diclofenac may lead to immune haemolytic anaemia (IHA) owing to the presence of drug-dependent antibodies and/or autoantibodies. A relationship with oral or intramuscular drug administration is unknown. Here, we describe a patient who apparently tolerated oral diclofenac but developed severe IHA following intramuscular injection of the drug.

PATIENTS AND METHODS

A 66-year-old-female was admitted to hospital because of jaundice and nausea, which were initially presumed to be manifestations of a postcholecystectomy syndrome. The patient soon developed haemolysis and renal failure. Although the symptoms and signs were suggestive of autoimmune haemolytic anaemia (AIHA), the patient had diclofenac-induced IHA.

RESULTS

Serological testing, including detection of drug-dependent antibodies, was performed using standard techniques. The patient's serum was found to contain a highly reactive diclofenac-dependent red cell antibody of the immune complex type (titre 256 000). She recovered after 7 weeks of treatment with prednisolone, blood transfusions, haemodialysis and plasma exchange.

CONCLUSIONS

Diclofenac-induced IHA should always be considered when a patient on diclofenac develops haemolysis.

Acyl glucuronide reactivity in perspective: biological consequences

The metabolic conjugation of exogenous and endogenous carboxylic acid substrates with endogenous glucuronic acid, mediated by the uridine diphosphoglucuronosyl transferase (UGT) superfamily of enzymes, leads to the formation of acyl glucuronide metabolites. Since the late 1970s, acyl glucuronides have been increasingly identified as reactive electrophilic metabolites, capable of undergoing three reactions: intramolecular rearrangement, hydrolysis, and intermolecular reactions with proteins leading to covalent drug-protein adducts. This essential dogma has been accepted for over a decade. The key question proposed by researchers, and now the pharmaceutical industry, is: does or can the covalent modification of endogenous proteins, mediated by reactive acyl glucuronide metabolites, lead to adverse drug reactions, perhaps idiosyncratic in nature? This review evaluates the evidence for acyl glucuronide-derived perturbation of homeostasis, particularly that which might result from the covalent modification of endogenous proteins and other macromolecules. Because of the availability of acyl glucuronides for test tube/in vitro experiments, there is now a substantial literature documenting their rearrangement, hydrolysis and covalent modification of proteins in vitro. It is certain from in vitro experiments that serum albumin, dipeptidyl peptidase IV, tubulin and UGTs are covalently modified by acyl glucuronides. However, these in vitro experiments have been specifically designed to amplify any interference with a biological process in order to find biological effects. The in vivo situation is not at all clear. Certainly it must be concluded that all humans taking carboxylate drugs that form reactive acyl glucuronides will form covalent drug-protein adducts, and it must also be concluded that this in itself is normally benign. However, there is enough in vivo evidence implicating acyl glucuronides, which, when backed up by in vivo circumstantial and documented in vitro evidence, supports the view that reactive acyl glucuronides may initiate toxicity/immune responses. In summary, though acyl glucuronide-derived covalent modification of endogenous macromolecules is well-defined, the work ahead needs to provide detailed links between such modification and its possible biological consequences.