China
Africa
Explore chapters and articles related to this topic
Abnormal Red Cell Metabolism
Published in Harold R. Schumacher, William A. Rock, Sanford A. Stass, Handbook of Hematologic Pathology, 2019
G6PD deficiency is suspected in patients who develop acute hemolytic anemia after administration of oxidant drugs or after an infectious episode. G6PD deficiency is also suspected in patients with hereditary nonimmune hemolytic anemia. Several commercial kits are available to screen for G6PD deficiency (9). Two commonly used tests are as follows. Fluorescent spot test: Whole blood is added to a mixture of glucose 6-phosphate, NADP, and saponin. A drop of this mixture is placed on a filter paper and observed for fluorescence in ultraviolet light. In the presence of G6PD, NADP is converted to NADPH, which shows bright fluorescence.Ascorbate cyanide test: Whole blood is incubated with a mixture of sodium cyanide and sodium ascorbate. Hydrogen peroxide becomes available to oxidize hemoglobin to methemoglobin, showing a brown color. Sodium cyanide is used in the test to inhibit catalase in the red cells. In the absence of G6PD, the reaction takes place more rapidly than in normal cells.
Treatment and prevention of malaria
Published in David A Warrell, Herbert M Gilles, Essential Malariology, 2017
David A Warrell, William M Watkins, Peter A Winstanley
Tafenoquine is an 8-aminoquinoline drug developed by the US Army Program (Peters, 1999). It is a 5-phenoxy derivative of primaquine with a longer elimination half-life (14 days compared to 6 hours) and, in animal models, is seven times more active than primaquine as a hypnozoitocide, 14 times more active as a causal prophylactic and 100 times more active as a blood schizontocide. It is better tolerated than primaquine, but can cause haemolysis in people with G6PD deficiency. Tafenoquine has great potential as a causal prophylactic drug against P. falciparum, for the radical cure of P. vivax, as a gametocytocidal and possibly blood schizontocidal drug for P. falciparum.
The Pale Child
Published in Michael B O’Neill, Michelle Mary Mcevoy, Alf J Nicholson, Terence Stephenson, Stephanie Ryan, Diagnosing and Treating Common Problems in Paediatrics, 2017
Michael B O’Neill, Michelle Mary Mcevoy, Alf J Nicholson, Terence Stephenson, Stephanie Ryan
G6PD deficiency is an X-linked recessive disorder caused by mutations in the G6PD gene. More than 300 varieties of G6PD deficiency have been identified. Clinical manifestations include:asymptomaticneonatal jaundicehaemolysis – episodic or chronic.
Prevalence of G6PD deficiency in Thai blood donors, the characteristics of G6PD deficient blood, and the efficacy of fluorescent spot test to screen for G6PD deficiency in a hospital blood bank setting
Published in Hematology, 2022
Phinyada Rojphoung, Thongbai Rungroung, Usanee Siriboonrit, Sasijit Vejbaesya, Parichart Permpikul, Janejira Kittivorapart
Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked inherited disorder that is characterized by the insufficiency of an enzyme that is used in the pentose phosphate pathway to generate nicotinamide adenine dinucleotide phosphate (NADPH). NADPH is a crucial oxidation reduction molecule that protects red blood cells (RBC) from reactive oxygen species (ROS). Patients with G6PD deficiency manifest varying degrees of acute hemolysis in response to oxidative stress precipitated by certain medications and foods. Transfusion of red cell products from G6PD enzyme deficient donors could cause a potentially unfavorable outcome, especially in newborns and those with hemoglobinopathies [1–3]. Current screening criteria of blood donors relative to red cell disorders in Thailand relies mostly on history taking and point-of-care hemoglobin (Hb) testing. The screening of G6PD deficiency is not performed in the donors at the moment. According to the World Health Organization (WHO) Blood Donor Selection guidelines, only donors with a previous history of hemolysis are to be permanently deferred [4]. However, countries with a high prevalence of G6PD deficiency should establish their own criteria for screening at-risk donors, and they should establish their own transfusion guidelines [5].
Glucose-6-phosphate dehydrogenase deficiency screening and gene analysis in blood donors of Guangdong province
Published in Hematology, 2022
Hong-Feng Liang, Fen Lin, Jin Lu, Zhi-Xiao Chen, Li-Ye Yang
Glucose-6-phosphate dehydrogenase (G6PD) deficiency, an X-linked disorder affecting the ability of RBCs to handle oxidant stress, is the most common human enzymopathy, approximately 400 million people are affected worldwide [1]. G6PD deficiency results from deleterious variants in the housekeeping gene of G6PD, causing impaired response to oxidizing agents [1]. G6PD deficiency is very common in southern China. According to recent reports, the overall prevalence of G6PD deficiency in China is 2.10% at the national level, the top six common mutations are c.1388 G > A, c.1376 G > T, c.95 A > G, c.392 G > T, c.871 G > A, and c.1024 C > T, accounting for more than 90% of G6PD-deficient alleles in China [2]. The prevalence varies in different parts of China, and G6PD deficiency prevalence is estimated to be around 2.4% in Sichuan province [3], 4.08% in Dongguan of Guangdong province [4], and 7.28% in Guangxi province [5]. Most adults with G6PD deficiency usually do not have any symptoms. Blood donors with G6PD deficiency are usually unaware of their condition and are likely to join the blood donation program. The present regulations of China do not require G6PD deficiency screening before blood donation, blood bank also do not perform this test, and G6PD-deficient erythrocytes are likely to be transfused into blood recipients.
Dapsone-induced methemoglobinemia and hemolysis in a woman without G6PD deficiency presenting with idiopathic urticaria
Published in Hematology, 2022
Yang Hu, Mimansa Geere, Maham Awan, Andrew D. Leavitt, Laura E. Brown, Hadley J. Pearson, Jocelyn S. Gandelman, Scott C. Kogan
We considered several possibilities as to why the patient experienced dapsone-induced hemolysis and developed morphologic abnormalities of red blood cells. We considered undiagnosed G6PD deficiency as well as functional insufficiencies in kidney, liver, or spleen. The patient had no family history, supporting blood tests, or prior diagnoses suggesting these issues. G6PD deficiency is uncommon in women as the gene is X-linked and usually requires two mutations to result in severe disease [21]. It is be possible that the patient has a heterozygous G6PD mutation that affects protein function, and such carriers can exhibit hemolysis when exposed to oxidizing agents including dapsone [22,23]. Such carriers can have significant subset of red cells that are G6PD deficient, and flow cytometry is able to distinguish G6PD deficient and G6PD replete red blood cells and thereby determine risk of drug-induced hemolysis in these individuals [24]. To date, we have not performed genetic testing or flow analysis to definitively assess this possibility but given the absence of a family history of G6PD deficiency such heterozygosity is not likely. Another consideration was the possibility of a pre-existing hemolytic anemia that may have elevated the patient’s G6PD levels; however, the patient’s baseline hemoglobin was within normal limits. It could also be possible that the patient has a rare, undiagnosed hemoglobinopathy and indeed, dapsone use in the setting of hemoglobinopathy Hasharon has been reported to cause methemoglobinemia and hemolysis in one case report [25].