Drug-induced Haemolytic Anaemia

Antibody based therapeutics for autoimmune hemolytic anemia

INTRODUCTION

Autoimmune hemolytic anemia (AIHA) treatment has been revolutionized by the introduction of target therapies, mainly monoclonal antibodies (MoAbs).

AREAS COVERED

The anti-CD20 rituximab, which targets Ab production by B-cells, induces 80% of response in warm-type AIHA (wAIHA) and 50-60% in cold agglutinin disease (CAD). Other B-cell targeting MoAbs including ianalumab, povetacicept, and obexelimab are under active study. The anti-CD38 MoAb daratumumab has been used in several reports to target long-lived plasma-cells responsible for AIHA relapse, being effective even in multi-refractory cases. Anti-complement MoAbs will soon change the treatment paradigm in CAD; the anti-C1s sutimlimab rapidly increased Hb in more than 80% of the cases. Finally, MoAbs inhibiting the neonatal Fc receptor (FcRn), such as nipocalimab, can reduce the half-life of the pathogenic autoAbs, representing a promising treatment for wAIHA.

EXPERT OPINION

MoAbs offer the potential to improve efficacy by reducing toxicity. However, there is a huge need for clinical trials exploring response duration rather than short-term efficacy. Complement inhibitors and anti-FcRns do not abrogate autoAb production and are being developed as long-term therapies. Thus, the combination of B-cell/plasma cell targeting drugs deserves to be explored. On the other hand, their rapid efficacy should be exploited for the acute AIHA phase.

Alectinib-Induced Severe Hemolytic Anemia in a Patient with ALK-Positive Non-Small Cell Lung Cancer: A Case Report

Alectinib is a selective anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitor as standard therapy for ALK-rearranged non-small cell lung cancer (NSCLC). Hemolytic anemia is considered as a rare but significant adverse event with alectinib. Here, we report a case of a 73-year-old female with lung adenocarcinoma, harbouring an ALK fusion gene, who received alectinib as second-line therapy and developed gradually progressive grade 4 (6.4 g/dL) drug-induced hemolytic anemia (DIHA) after complete response. We discontinued alectinib and performed a blood transfusion for the severe anemia. The anemia improved with no recurrence of lung adenocarcinoma over 10 months. Regular hematologic monitoring and the possibility of DIHA should be considered in case of progressive hemolytic anemia during alectinib treatment.

Significance of multiple types of antibodies on red blood cells of patients with positive direct antiglobulin test: a study of monospecific antiglobulin reactions in 85 patients

Blood samples from 85 patients with a positive direct antiglobulin test were tested with monospecific antiglobulin reagents: anti-IgG, anti-IgM, anti-IgA, and anti-C3. No typical pattern of antiglobulin reaction could be correlated with specific diseases except for the patients with methyldopa-induced positive direct antiglobulin test, all of whom had only IgG on their red blood cells. The presence of more than 1 type of antibody on red blood cells was associated with severe haemolysis. These patients responded less frequently to steroids, and in most of them no underlying disease could be found. Most patients with complement alone on red blood cells had no evidence of haemolysis, and when present it was never severe.

Drug dependent red cell antibodies and intravascular haemolysis occurring in patients treated with 9 hydroxy-methyl-ellipticinium

Eleven patients were treated weekly with a new cytostatic drug, 9-hydroxy-methyl-ellipticinium (9 HME). Eight were treated for longer than 4 weeks and three of these developed a drug dependent antibody reacting with normal red cells. In two of these patients acute intravascular haemolysis occurred, one with oliguric renal failure; in the third patient the drug was stopped as soon as the antibody was detected. In all three patients the antibody developed after 4 weeks of treatment. It was IgM, agglutinated normal red cells and bound complement only in the presence of the drug. No antibodies could be detected in the patient's serum reacting with normal platelets in the presence of the drug. The incidence of haemolysis with this drug is much higher than seen with other drugs causing immune-complex haemolysis. Studies done with closely related substances suggest that the antigenic site of the drug is related to the group attached to carbon atom 9.

Triamterene-induced immune haemolytic anaemia with acute intravascular haemolysis and acute renal failure

Acute intravascular haemolysis and renal failure developed while a patient was taking triamterene. A direct antiglobulin test with a polyvalent reagent was positive. Serum caused agglutination of normal red cells in the presence of triamterene and caused an increase of partial haemolysis of both trypsin-treated erythrocytes and red cells from a patient with paroxysmal nocturnal haemoglobinuria (PNH) in the presence of complement. From the results of antibody-neutralization test and treatment with 2-mercaptoethanol, the presence of IgM antibody with lambda light chain could be demonstrated. The triamterene seemed to bind strongly to the red cells in vitro but in vivo there was no detectable adsorption to red cells. Haptenic inhibition was not demonstrated. From these results, it was assumed that this antibody was found to cross-react with methotrexate which has a structure similar to that of triamterene.

[Penicillin-induced immunhaemolytic anaemia. In vitro studies using separated monocytes (author's transl)]

Under certain conditions human monocytes were able to bind and ingest red cell-antibody complexes in vitro. Using penicillincoated red cells and purified monocytes we investigated sera of patients with penicillin allergy. It was shown that sera containing IgG-antibodies against penicillin induced the binding of penicillin-coated red cells to isolated monocytes provided IgG-antibodies of high titer were present. Inhibition and absorption tests demonstrated the specificity of the reaction in terms of IgG-antibodies and the drug. Monocyte binding was also studied in respect to the cross reactivity of penicillin antibodies and cephalosporins. We concluded that antipenicillin-antibodies of the IgG-class were able to induce an immunphagocytosis in vitro, if the drug was present in the test system. The reaction was dependent on the amount of antibodies of the IgG-class.

Immune haemolytic anaemia and renal failure induced by streptomycin

A case of acute immune haemolytic anaemia and renal failure induced by streptomycin, is reported. The clinical features are similar to those in a case previously reported in which no in vitro proof of antibodies was obtained. In this case, streptomycin-specific IgG antibodies, with both k and lambda light chains, could be demonstrated. The streptomycin bound strongly to the red cell membrane, apparently through chemical groups related to the M antigen and possibly also to the D antigen. Complement-fixation by the drug-specific IgG antibodies, after reaction with the streptomycin-coated red cells, could also be demonstrated. On the basis of these findings, our conclusion is that a complement-fixing hapten-cell mechanism was the main cause of the intravascular haemolytic episode suffered by the patient on exposure to streptomycin. This drug had been prescribed 15 years earlier for pulmonary tuberculosis and he had since injected himself with it whenever he felt "flu" symptoms, without harmful effects, until now.