Drug-Induced Oxidative Haemolysis

Epidemiological and clinical aspects of blackwater fever among African children suffering frequent malaria attacks

Blackwater fever (BWF), one of the commonest causes of death of Europeans living in Africa at the beginning of the twentieth century, but rarely diagnosed since the 1950s, is related to Plasmodium falciparum malaria but there is considerable debate and controversy about its aetiology. From 1990 to 2000, the whole population of Dielmo, a village in Senegal, was involved in a prospective study of malaria. Three cases of BWF occurred in 3 children aged 4, 7 and 10 years, belonging to a subgroup of children who suffered malaria attacks every 4 to 6 weeks over many years, who had received repeated quinine treatment. The spread of chloroquine resistance, by increasing the use of more toxic alternative drugs, may expose endemic populations to a high incidence of severe side effects of antimalarials.

Ciprofloxacin-induced acute interstitial nephritis and autoimmune hemolytic anemia

Ciprofloxacin has been associated with several side effects including interstitial nephritis and hemolytic anemia. The combination of both side effects is extremely rare. In this report, we describe a case of ciprofloxacin-induced interstitial nephritis and autoimmune hemolytic anemia. Hemolytic anemia improved after stopping the drug and initiation of steroid therapy. Unfortunately, acute interstitial nephritis was irreversible and the patient developed end-stage renal disease.

Application of hematopoietic progenitor assays for the estimation of hematotoxicity in rats

In a study to employ progenitor-derived clonogenic assays of granulocyte-macrophage colony-forming units (CFU-GM) and erythroid colony-forming units (CFU-E) for the assessment of chemically induced hematotoxicity in rats, we sought the appropriate culture medium for each assay. Then, the effect of cyclophosphamide or phenylhydrazine on bone marrow cells was examined in vivo and in vitro. Oral treatment of rats with 25 mg/kg of cyclophosphamide significantly decreased the number of CFU-GM, which was an earlier and more sensitive index than were other hematological parameters tested. Direct exposure of the culture to cyclophosphamide had little effect on CFU-GM production, but addition of sera from rats pretreated with cyclophosphamide strongly depressed their formation, which suggested that the active metabolites of cyclophosphamide produced in the body may play an important role in toxicity. Subcutaneous injection of rats with 40 mg/kg of phenylhydrazine produced a marked increase in CFU-E 6-24 hr after injection. Direct exposure of the culture to phenylhydrazine had severe cytotoxic effects, but addition of sera from rats receiving phenylhydrazine resulted in increased numbers of CFU-E, probably indicative of increases in endogenous erythropoietin in donor rats. These results demonstrate that the proper use of progenitor assays in the in vivo and in vitro studies may be a valuable tool for approaching the mechanism underlying hematotoxicity.

Acute lindane intoxication: a study on lindane tissue concentration and oxidative stress-related parameters in liver and erythrocytes

Treatment of rats with daily doses of 20 mg of lindane/kg for 3 consecutive days led to the accumulation of the insecticide in several tissues, including erythrocytes and liver. Lindane did not alter the hematocrit and hemoglobin concentration but reduced methemoglobin levels by 17%. Red blood cells from controls and lindane-treated rats, exposed to t-butyl hydroperoxide, exhibited comparable rates of oxygen uptake and visible chemiluminescence, whereas the induction period that precedes oxygen uptake was significantly enhanced in the latter group. Lindane treatment did not modify the activity of erythrocyte glutathione peroxidase, glucose-6-phosphate dehydrogenase, catalase, and methemoglobin reductase, being the total content of glutathione and superoxide dismutase activity significantly increased. The liver from lindane-treated rats showed an enhanced microsomal pro-oxidant activity, evidenced by higher cytochrome P450 content and NADPH-cytochrome c reductase and NADPH oxidase activities. The higher enzyme activities led to an increased superoxide anion generation (adrenochrome formation) and lipid peroxidation (measured either by the production of thiobarbituric acid reactants and spontaneous visible chemiluminescence). Concomitantly, liver glutathione content and the activity of glutathione peroxidase-glutathione reductase couple were augmented by lindane treatment, without any change in superoxide dismutase activity, together with a reduction in that of catalase. Results suggest that lindane does not alter the prooxidant/antioxidant status of the erythrocyte in conditions of a significant cellular accumulation of the insecticide, which might exert direct action on enzymatic systems leading to enhanced superoxide dismutase activity and glutathione content.(ABSTRACT TRUNCATED AT 250 WORDS)

Dapsone: modes of action, toxicity and possible strategies for increasing patient tolerance

Dapsone is useful in the treatment of a number of inflammatory conditions which are characterized by neutrophil infiltration. It is the drug of choice for suppression of the symptoms of dermatitis herpetiformis, as it inhibits the process by which neutrophils leave the circulation and migrate to lesional sites. It also prevents the tissue destruction normally caused by the neutrophils' respiratory burst. Although dapsone can cause a number of serious idiosyncratic reactions, such as agranulocytosis, tolerance of the drug at higher doses is more usually determined by its haematological side-effects of methaemoglobinaemia and haemolysis. These effects are due entirely to the hepatic N-hydroxylation of dapsone to a hydroxylamine metabolite, some of which escapes from the liver and rapidly enters red cells. Attempts have been made to counteract the haemotoxic effects of the metabolite by the use of antioxidants such as vitamins E and C. Recently, the co-administration of a metabolic inhibitor such as cimetidine has been shown to reduce significantly dapsone-dependent methaemoglobinaemia, without any change in drug efficacy. It remains to be seen if this approach will be adopted clinically, to improve patient tolerance of high dapsone dosage.

Long-term, low-dose aspirin is safe in glucose-6-phosphate dehydrogenase deficiency

Forty-four patients with Mediterranean-type glucose-6-phosphate dehydrogenase (G-6-PD) deficiency receiving long-term, low-dose aspirin were monitored over three months for evidence of hemolysis. Complete blood count, reticulocyte count and serum bilirubin were normal in all patients before treatment and upon periodic retesting. We conclude that there is sufficient current evidence to remove the hemolytic stigma of aspirin in G-6-PD deficiency, thereby establishing its safety for long-term therapy in this condition.

Evidence for oxidative damage to red blood cells in mice induced by arsine gas

In animals and human beings exposed to arsine gas (AsH3) a severe and fulminant lysis of erythrocytes occurs. Little is known about the effects of subchronic exposure on the hematopoietic system or about the mechanism of hemolysis produced by arsine gas. To examine these, we exposed male and female mice to 0.000, 0.025, 0.500 and 2.500 ppm arsine gas for 6 h a day, 5 days a week during a 90-day period. After 5, 15, and 90 days of exposure, blood was collected and routine hematologic profiles were performed to document the effects of arsine gas on peripheral blood. A moderate hemolytic anemia, indicated by decreases in erythrocyte counts, hematocrits, hemoglobin concentrations and increases in mean corpuscular hemoglobins and mean corpuscular hemoglobin concentrations, was seen in blood samples collected after 5 days of exposure. In blood collected after 15 and 90 days of exposure, the anemia was less severe but a greater increase in mean corpuscular volumes and absolute reticulocyte counts revealed an active regenerative response. Higher concentrations of methemoglobin in animals in the 2.500 ppm exposure group (measured after 90 days of exposure) indicated that the rate of oxidation of heme (ferrous to ferric) increased due to exposure to arsine gas. Additionally, the presence of Heinz bodies in blood smears stained with brilliant cresyl blue and decreases in reduced glutathione concentrations in red blood cells exposed to arsine gas in vitro provide evidence that the mechanism of hemolysis involves depletion of intracellular reduced glutathione resulting in an oxidation of sulfhydryl groups in hemoglobin and possibly red cell membranes.

Relationship between exposure to icterogenic agents, glucose-6-phosphate dehydrogenase deficiency and neonatal jaundice in Nigeria

In a study of the relationship between exposure to icterogenic agents, G-6-PD deficiency and severe neonatal jaundice (NNJ) (serum bilirubin greater than or equal to 205 mumol/l) in 234 Nigerian term male neonates, 106 infants with severe NNJ and 128 controls, it was found that 62.3% of the jaundiced infants and 13.3% of the infants without NNJ were G6PD deficient (p less than 0.01). The proportion of infants exposed to icterogenic agents in the two groups was very similar (p greater than or equal to 0.5). There was a strong association between exposure to icterogenic agents and NNJ in 83 G6PD deficient infants (p less than 0.01), but there was no association between exposure to icterogenic agents and NNJ in the whole group of 234 infants or in 151 infants with normal G6PD status. It is concluded that there is an association between genetically determined G-6-PD deficiency and exogenous agents in causing severe NNJ in Nigerian infants.

Drug-induced red cell dyscrasias

Major advances have been made in recent years in our understanding of the pathogenetic mechanisms of drug-induced blood dyscrasias, particularly those involving the red cell. Among the latter, hemolytic anemia is the most common. Drug-induced red cell destruction may occur on an immune basis or through disruption by the drug of red cell metabolism. The immunological basis of drug-induced hemolysis is reviewed with emphasis on the clinical and laboratory manifestations, differential diagnosis and the major mechanisms involved. Drug-induced oxidative hemolysis both in normal individuals and in those with certain enzymopathies, notably glucose-6-phosphate dehydrogenase deficiency, is summarized. Drugs may also produce red cell dyscrasias by acting on the immature erythroid compartment. Some of these inhibit erythroid growth by as yet poorly understood mechanisms. Others exert more specific metabolic effects in erythroid precursors. These include drugs which interfere with DNA synthesis causing megaloblastic erythropoiesis and those which disrupt mitochondrial function and the synthesis of heme manifested by sideroblastic erythropoiesis. A brief consideration of heme biosynthesis and the action of drugs which are associated with sideroblastic anemia, including the antituberculous agents, lead, alcohol and chloramphenicol is presented. Finally, where pertinent, an updated listing of drugs involved in red cell dyscrasias is included.

Susceptibility of glucose-6-phosphate dehydrogenase deficient red cells to primaquine enantiomers and two putative metabolites--I. Effect on reduced glutathione, methemoglobin content and release of hemoglobin

The effects of the primaquine (PQ) enantiomers, (+)PQ and (-)PQ, and two putative metabolites [5-hydroxyprimaquine (5HPQ) and 6-desmethyl-5-hydroxyprimaquine (6D5HPQ)] on methemoglobin (Met Hb) and glutathione content and release of hemoglobin into plasma from glucose-6-phosphate dehydrogenase (G-6-PD) deficient red cells were studied in vitro. The results show that a 1.5 mM concentration of (-)PQ produced a significantly greater increase in Met Hb content and decrease in reduced glutathione (GSH) level than did (+)PQ. However, the release of plasma hemoglobin was greater with (+)PQ than with (-)PQ. The hydroxy derivatives of primaquine, 5HPQ and 6D5HPQ, were significantly more active than PQ. Their individual effects differed; whereas 5HPQ produced significantly greater reduction in GSH compared to 6D5HPQ, the effect of 6D5HPQ on Met Hb content and release of plasma hemoglobin was greater than that of 5HPQ. The qualitative effects of these compounds on normal, heterozygous and hemizygous G-6-PD deficient red cells were similar, but quantitatively the effects were greatest on hemizygous G-6-PD deficient cells and intermediate on heterozygous cells.

Air pollution impact on phagocytic capacity of peripheral blood macrophages and antioxidant activity of plasma among school children

Peripheral blood macrophages of school children from downtown Santiago, Chile--a highly polluted city--exhibited a lower phagocytic index with higher percentage of killing than those of the rural village of María Pinto. These findings were observed concomitantly with a lower antioxidant activity of plasma in Santiago students. No differences were observed in serum immunoglobulins (IgA, IgG, and IgM), secretory IgA in saliva, and complement component C3. White blood cell count was higher in María Pinto residents than in Santiago students, including those cells with phagocytic capacity. It is suggested that particulate air pollution may enhance macrophage activity with impairment of the antioxidant capacity of plasma.

Induction of hemolytic anemia by nonsteroidal antiinflammatory drugs

The incidence of immune hemolytic anemia (IHA) is increasing. The proliferation of pharmaceuticals is a contributing factor to this increase. IHA is an uncommon, though significant, adverse effect of a wide variety of drugs. Several recent case reports have implicated the nonsteroidal antiinflammatory drugs (NSAIDs). Because of the extensive use of this class of drugs, a review of case reports, clinical studies, and in vitro research was conducted on NSAID-induced IHA. Mefenamic acid, ibuprofen, sulindac, naproxen, tolmetin, feprazone, and aspirin are reported to cause IHA, with mefenamic acid most frequently implicated. Mefenamic acid appears to cause hemolytic anemia by an autoimmune mechanism similar to methyldopa and aspirin by an immune complex mechanism. However, there is insufficient information concerning ibuprofen, sulindac, naproxen, tolmetin, and feprazone to assign specific mechanisms of immune hemolysis. In individuals with glucose-6-phosphate dehydrogenase (G-6-PD) deficiency, aspirin at usual therapeutic doses is not a predisposing factor to hemolysis unless other risk factors are present. Although individuals with G-6-PD deficiency are at increased risk of developing hemolytic anemia when exposed to oxidizing stresses, the use of NSAIDs does not appear to increase this risk significantly. Because NSAID-induced IHA occurs infrequently and the sensitivity of currently used tests to detect drug-dependent antibodies is limited, routine serologic testing in patients receiving NSAIDs is not justified. If hemolytic anemia occurs in a NSAID-treated patient and the history is consistent with a drug-induced etiology, the NSAID should be discontinued. With discontinuation of the offending agent, the prognosis is good. There is a rapid hematologic recovery, with a slow resolution of abnormal serologic findings.

Effects of nine synthetic putative metabolites of primaquine on activity of the hexose monophosphate shunt in intact human red blood cells in vitro

Suspensions of washed human red blood cells were treated with nine synthetic putative metabolic derivatives of primaquine (PQ'), and their individual effects on activity of the hexose monophosphate shunt (HMS) were quantitated by radiometric analysis of 14CO2 from [14C] glucose. The most potent HMS stimulant was 5-hydroxy-6-methoxy-8-aminoquinoline (5H6MQ), which caused 10-fold elevation of HMS activity at an estimated concentration of 0.004 mM. Ten millimolar primaquine (PQ) was required to achieve the same effect. Thus, 5H6MQ was approximately 2500-fold more reactive with the HMS than PQ. Other analogs achieved less than 0.4- to 154-fold increases in HMS reactivity. Patterns of effects on HMS activity indicated that 5-hydroxylation and/or N-dealkylation of PQ strongly enhanced HMS reactivity. In contrast, none of the putative metabolites of PQ activated the proteolytic system known to degrade oxidized protein in red cells, indicating that stimulation of the HMS by the PQ analogs was not related to an injurious oxidative stress. Red cells pretreated with 1.0 mM N-ethylmaleimide (NEM) or with 1.0% (w/v) sodium nitrite to cause glutathione sulfhydryl blockage and conversion of red cell hemoglobin to methemoglobin (metHb), respectively, also showed elevation of HMS activity when exposed to 5H6MQ. These observations suggested that 5H6MQ-induced elevation of HMS activity was at least partially independent of glutathione redox reactions, hydrogen peroxide accumulation and reaction with oxyhemoglobin. The relevance of these observations to proposed mechanisms of hemolytic toxicity of PQ is discussed.

Methylene blue-mediated hexose monophosphate shunt stimulation in human red blood cells in vitro: independence from intracellular oxidative injury

The red blood cell hexose monophosphate shunt (HMS) and proteolytic responses to several concentrations of Methylene Blue or sodium nitrite were measured. The results suggested two distinct mechanisms for activation of the HMS: (1) nitrite treatment increased HMS activity in response to oxidative challenge to red cell protein; (2) Methylene Blue treatment activated HMS without injurious oxidative challenge. Nitrite-treated cells actively degraded protein, whereas Methylene Blue-treated red cells did not activate proteolytic systems that degrade oxidized red cell protein. These observations are relevant to proposed in vitro systems for evaluation of drug hemolytic toxicity potential on the basis of HMS stimulation capacity.

An in vitro micro-volume procedure for rapid measurement of erythrocytic hexose monophosphate shunt activity

A radiometric micro-volume procedure for measurement of erythrocytic hexose monophosphate shunt (HMS) activity in intact cells in vitro is described. The procedure is rapid, allowing 200 individual HMS determinations in a single experiment of 5 hr duration. The procedure is reproducible, yielding HMS activity means insignificantly different (P greater than 0.05) between replicate experiments. A profile of sodium nitrite-induced HMS stimulation is reported: HMS was elevated 2-fold (P less than 0.001) between zero and 2.5 mM NaNO2; HMS elevation was more distinct (7-fold) between 2.5 and 5.0 mM NaNO2; maximum activity (22-fold) was observed between 10 and 20 mM NaNO2; greater than 20 mM NaNO2 caused significant (P less than 0.001) diminution of HMS; glucose carbon recycling through the HMS occurred only with greater than 2.5 mM NaNO2 where this process contributed less than or equal to 16% to total HMS activity.

Toxicological screening models: drug-induced oxidative hemolysis

In an attempt to obtain a simple screening system for the assessment of toxic-hemolytic effects of chemical substances, a battery of hematological tests was used. Phenacetin served as reference substance. The drug caused reversible formation of methemoglobin and Heinz bodies and an increase in peripheral reticulocytes after 2 and 4 weeks of treatment. Furthermore, an increase in the mean corpuscular volume of red blood cells (RBC) and the volume of RBC ghosts in hypotonic solutions, and a decrease of the mean corpuscular fragility was observed. The latter changes are considered to be a consequence of regenerative RBC compensation rather than due to structural membrane alteration caused by the drug. The results suggest that only a combination of several hematological tests can provide comprehensive information about the hemolytic potential of chemical substances, and that for screening purposes small numbers of animals are often sufficient.