**5.4. Chronic nonspherocytic anemia**

72 Dehydrogenases

acid number 188 substitution of serine to phenylalanine (Vulliamy*, et al.*, 1988). Second is a silent mutation result of a cytosine to thymine mutation at nucleotide number 1311 (Beutler, 1990). There are many similar Class II variants in the Mediterranean region (Cagliari, Sassari, El Fayoum), South Asia (Hong Kong, Canton, Mahidol), and elsewhere. Most of these emerge as a consequence of point mutations resulting in single amino acid mutations that have variable effects on activity and electrophoretic mobility (Luzzatto & Battistuzzi,

Depending on G6PD enzyme deficiency are: Hemolytic Anemia (Drug-induced hemolysis), Diabetes mellitus-induced hemolysis and Infection-induced hemolysis; chronic

**5.1.1 Mechanism of hemolysis.** In some people, for example, the Mediterranean-type, G6PD deficiency from drug intake occurs, although not a permanent hemolytic condition. In erythrocytes, NADPH cannot form with G6PD deficiency and unformed NADPH creates a deficiency in conversion of the oxidized form of glutathione (GSSG), to its reduced form (GSH) (Lachant*, et al.*, 1984, Beutler, 1994). There is normally plenty of GSH in erythrocytes and it protects the cell from oxidizing agents. If G6PD is deficient, hemoglobin is oxidized by oxidative substances to be eliminated and it returns methemoglobin that cannot function normally. Also, hemoglobin precipitates with denaturation in the cytoplasm forms Heinz bodies. These structures attach to the membrane with disulfide bonds and disrupt its normal structure. The erythrocytes that contain Heinz bodies in their cytoplasm are sequestered by macrophages in the spleen and removed from the circulation. G6PD deficiency hemolysis occurs like that in the extravascular compartment and also occurs again as a result of membrane defects (Alving*, et al.*, 1956). Thus, drug-induced hemolysis is the first and best-known morbid effect of G6PD deficiency. After a 1- or 2-day delay in such

The red blood cell (RBC) membrane was adhered to by Heinz bodies, which are particles of denatured protein. These appear in the early stages of drug administration and disappear as hemolysis progresses. Hemolysis usually occurs in blood vessels and hemoglobinuria follows. The increase of reticulocytes emerges in response to this situation and the hemoglobin level begins to increase again within 8-10 days (Beutler, 1994). In severe hemolysis, the patient may complain of back and stomach pain and the urine turns dark. The hemolytic anemia is self-limited when G6PD deficiency is relatively mild because only the older RBCs are destroyed and the young RBCs have normal or nearly-normal enzyme

Table 1 lists the drugs and chemicals that cause clinically significant hemolytic anemia.

drug administration, a fall in the hemoglobin (Hb) concentration occurs.

1985, Luzzatto, 1989, Beutler, 1990, Beutler, 1991, Beutler, 1992).

**5. Clinical tables on G6PD deficiency** 

**5.1. Hemolytic anemia** 

activity (Beutler, 1994).

nonspherocytic anemia, Favism and Neonatal jaundice.

Class I G6PD variants, such as the absence of precipitating factors in the occurrence of excessive hemolytic anemia, lower still further the remaining enzyme activity. This is observed in people with chronic hemolytic anemia and oxidative stress, even if unstable conditions occur as a result of insufficient enzyme activity in erythrocytes. Granulocyte dysfunction is seen in some cases. In these cases, more severe hemolysis is due to increased susceptibility to infection (Beutler, 1994, Luzzatto, 2001).

**5.5. Favism** is an illness that occurs in G6PD deficiency individuals with acute hemolysis by eating raw beans (Vicia fabu). Wet, dry or frozen fava bean ingestion of grains, even if the mother eats fava beans can cause hemolysis in newborn infants through breast milk may occur (Luzzatto, 2001). Individuals with G6PD deficiency hemolytic effect caused by the beans contained many glycosides that are toxic due to the visin and konvisin (Beutler, 1994, Akhter*, et al.*, 2011). In addition, β-glucosides in bean seeds, maturity stage of fava beans attain very high amounts causing a severe course of hemolytic crisis (Katz & Schall, 1979, Greene, 1993, Beutler, 1994). Often, in the G6PD Mediterranean variant, acute and a very severe hemolytic crisis are seen due to fava bean ingestion, even capable of causing death (Fairbanks, 1999, Luzzatto, 2001). In favism, damage in erythrocytes is similar to oxidative damage of drugs. Fava beans include visin, konvisin, ascorbic acid and L-Dopa, which have oxidative properties. The most commonly cited konvisin and visin glycosides during digestion fava beans by β-glycosidase or acid hydrolysis demolished to the active agents, which are converted to "divisine" and "izouramil." Divisine and izouramilin reduce the level of the GSH and NADPH in vitro conditions and damage the cell membrane by the formation of cross-connection with Heinz bodies; it also has been shown to inhibit Ca2+- ATPase and catalase (Arese & De Flora, 1990, Beutler, 1994, Gaetani*, et al.*, 1996, Luzzatto, 2001). 24-48 hours after ingesting foods like fava beans, characteristic symptoms occur in the form of pallor, jaundice and hemoglobinuria (Ninfali*, et al.*, 2000). In addition, jaundice,

headache, backache, nausea, fever, and chills are all signs of acute hemolysis (Tyulina*, et al.*, 2000). Favism is most common seen in children between the ages of 2-5, and is also 2-3 times more common in boys than in girls (Luzzatto, 2001). Clinical signs of favism begin earlier and are more severe than drug-induced hemolytic crises. Rarely, as a result of pollen of fava inhalation, hemolysis may occur within hours (Beutler, 1994). While each favism patient must have G6PD deficiency, hemolytic reactions may not occur after ingestion of fava beans in each person with G6PD deficiency. Each individual with G6PD deficiency of the same family could not be affected in the same way when they eat fava bean. On the other hand, changes are observed in the same person at different times. Genetic variations between individuals, differences of fava bean active metabolites may be responsible for these variable characteristics (Meloni*, et al.*, 1983, Group, 1989, Luzzatto, 2001).

Glucose-6-Phosphate Dehydrogenase

Deficiency and Malaria: A Method to Detect Primaquine-Induced Hemolysis *in vitro* 75

(Myrvang & Godal, 2000). It is widespread in tropical and subtropical regions of Asia, Africa and the American continents. Each year, malaria leads to deaths of millions of people all around the world and a large percentage of deaths are seen in Sub-Saharan regions of Africa. The causative agents of malaria are the Plasmodium parasites, which are transmitted to humans by the bites of infected mosquitoes. If patients are not treated with antimalarial drugs, malaria can easily lead to death. Five different types of Plasmodium species—*P. falciparum, P. vivax, P. ovalae, P. malariae* and *P.knowlesi*—lead to this disease (Wernsdorfer &

*Plasmodium falciparum (P. falciparum)* is the most serious and life-threatening form of the disease. 80% of death cases are reported from patients that have been infected with *P. falciparum*. It was also demonstrated that resistance has been developed in this type of parasites against current antimalarial drugs. It is generally seen in Africa, specifically in sub-Saharan regions. Interestingly, falciparum-derived malaria cases have been recently reported in various parts of the world where this parasite species was believed to be

*Plasmodium vivax (P. vivax)* constitutes a milder form of the disease. Vivax infections generally do not cause death. However, individuals that suffer from vivax infection also need to be treated. Among all *Plasmodium* species, *P. vivax* is the one that shows the broadest geographic distribution worldwide. Causative agents for 60% of malaria infections are reported as *P. vivax* infections in India. This parasite has a liver stage and can remain in the body for years without causing sickness. If the patient is not treated, the liver stage may re-activate and cause

*Plasmodium ovale (P. ovale*) is known as one of the other milder form of the disease. Like *P. vivax*, it generally does not commonly lead to death. Nevertheless, infected individuals require medical therapy. This parasite, similar to *P.vivax*, can live in the liver for long periods without causing symptoms. Therefore, if it is not treated, reactivation of parasites

*Plasmodium malariae (P. malariae)* is also another milder form of the disease. It does not commonly lead to death. However, it still requires treatment. This type of *Plasmodium*

*Plasmodium knowlesi (P. knowlesi)* causes malaria in macaques, but can also infect humans

When life cycles of Plasmodium parasites are investigated, it is seen that the parasites multiply in the liver of the human body, and then infect erythrocytes. As we mentioned before, *Plasmodium* parasites enter the human body when bitten by an infective female mosquito, which is called Anopheles. These mosquitoes become infected with malaria when they take *Plasmodium*-containing blood from an infected person. Approximately one week later, these parasites mix with the mosquito's saliva when the mosquito takes its next blood meal from another person and this individual is injected with *Plasmodium* parasites when

parasites are reported to stay in the blood of some individuals for several decades.

relapses—malaria attacks—after months, or even years without symptoms.

can be observed in the liver and this leads to relapse of the disease

(Mendis*, et al.*, 2001, Singh*, et al.*, 2004, Mueller*, et al.*, 2007).

they are being bitten (Bozdech*, et al.*, 2003).

McGregor, 1988, Sutherland*, et al.*, 2010).

completely eradicated.
