Segurança da cloroquina e hidroxicloroquina em pacientes com deficiência de glicose-6-fosfato desidrogenase (G6PD) e rastreamento da deficiência de G6PD em pacientes elegíveis para tratamento com cloroquina ou hidroxicloroquina devido à infecção por COVID-19 / Safety of chloroquine and hydroxychloroquine in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency and screening for G6PD deficiency in eligible patients for treatment with chloroquine or hydroxychloroquine due to COVID-19 infection

OBJETIVO Esta nota técnica tem por objetivo apresentar uma avaliação técnica sobre a segurança da cloroquina e da hidroxicloroquina em pacientes com deficiência de glicose6-fosfato desidrogenase (G6PD), visando a fornecer subsídios para a recomendação sobre o rastreamento da deficiência de G6PD em pacientes elegíveis para tratamento com cloroquina ou hidroxicloroquina devido à infecção por coronavírus (COVID-19). DOS FATOS Trata-se de despacho emitido pelo Gabinete do Ministro da Saúde (0014309411) em 06 de abril de 2020, anexado ao processo 25000.048031/2020-24. O referido despacho apresenta um e-mail direcionado à Chefia de Gabinete do Ministro da Saúde, encaminhado pela profissional Dra. Silmara Paula Gouvea de Marco, vinculada à Universidade de São Paulo, intitulado "Problema Sério com Cloroquina". Neste, a autora da mensagem relata preocupação com o "efeito colateral de alto nível em pacientes com deficiência de G6PD ­ Anemia Hemolítica", sugerindo que "antes de ministrar o medicamento, laboratórios rastreiem a Def de G6PD, pois tais pacientes podem vir a óbito caso façam uso de tal medicamento", fazendo referência à utilização de cloroquina em pacientes com infecção por coronavírus (COVID-19). O processo foi recebido por esta coordenação em 13 de abril de 2020. DA ANÁLISE: Os medicamentos cloroquina e hidroxicloroquina foram recomendados pelo Ministério da Saúde como possibilidade terapêutica em pacientes com diagnóstico confirmado da COVID-19, hospitalizados e com a forma grave da doença, em caráter off label, ou seja, sem indicação prévia em bula. Ressalta-se que a sugestão do uso pode ser modificada a qualquer tempo, a depender dos resultados das pesquisas científicas em curso A bula da cloroquina informa sua contraindicação para pacientes com deficiência de glicose-6-fosfato desidrogenase e a bula da hidroxicloroquina adverte que seu uso nesses pacientes deve ser feito com cautela. A cloroquina é uma 4-aminoquinolina tradicionalmente recomendada como antimalárico. Quando administrada em combinação com primaquina (8-aminoquinolina), confere cura radical aos pacientes infectados por Plasmodium vivax. Estudos conduzidos com a primaquina na década de 1950 identificaram risco aumentado de anemia hemolítica em pacientes com deficiência de G6PD tratados com primaquina. CONCLUSÕES A cloroquina apresenta contraindicação em bula para pacientes com deficiência de G6PD e a bula da hidroxicloroquina recomenda uso com cautela nesses pacientes. Apesar disso, as evidências atualmente disponíveis não apontam para risco aumentado da utilização desses medicamentos em pacientes com deficiência de G6PD. Dessa forma, não se justifica o rastreamento de deficiência de G6PD em todos os pacientes elegíveis para tratamento com cloroquina ou hidroxicloroquina devido à infecção por coronavírus (COVID-19).

G6PD deficiency; glucose 6 phosphate dehydrogenase deficiency; the case for mass screening in Pakistan

Hyperbilirubinemia due to glucose 6 phosphate dehydrogenase [G6PD] deficiency can cause permanent neurological damage and death in neonates. Screening for the enzyme enables timely diagnosis and treatment in cases of G6PD related kernicterus. Knowledge of patient G6PD status is also important in treatment of malaria, a disease endemic in Pakistan. World Health Organization recommends mandatoryuse of primaquine for radical cure and eradication of malaria. Since, Primaquine, causes hemolysis in G6PD deficient cases, widespread adoption of the drug is viewed with caution. This study assessed frequency of G6PD deficiency in Pakistani noenates and examines the need for its screening based on local disease prevalence and malaria endemicity. A cross sectional study was carried at Hematology Department, Army Medical College [MUST], in collaboration with Military Hospital, Rawalpindi, Pakistan.[January - August, 2011]. The frequency of G6PD deficiency in newborn population was determined by quantitative [spectrophotometric] method. Cord blood [2.5 ml blood in K3EDTA bottle] samples were obtained from 240 newborns [male: female 1.2:1] after informed consent from parents. Data obtained was analyzed using SPSS Windows version 17. Frequency of G6PD deficient cases was 4.2%. Among the ten G6PD deficient patients, six had severe enzyme deficiency [<10% enzyme activity]. The local prevalence of G6PD deficiency and its potential complications qualify it as a disease that must be screened for. Also, prior knowledge of patient G6PD status enables the physician to revert to modified treatment regimen for malaria only in enzyme deficient cases and not otherwise

Deficiencia de glucosa 6 fosfato deshidrogenasa en niños: caso clínico / Glucose-6-phosphate dehydrogenase deficiency in children: a case report

Introduction: Glucose-6-phosphate dehydrogenase deficiency (G6PD deficiency) is the most common red blood cell (RBC) enzyme disorder. The decrease as well as the absence of the enzyme increase RBC vulnerability to oxidative stress caused by exposure to certain medications or intake of fava beans. Among the most common clinical manifestations of this condition, acute hemolysis, chronic hemolysis, neonatal hyperbilirubinemia, and an asymptomatic form are observed. Objective: To analyze the case of a child who presented hemolytic crisis due to favism. Case report: A 2 year and 7 month old boy with a history of hyperbilirubinemia during the newborn period with no apparent cause, no family history of hemolytic anemia or parental consanguinity. He presented a prolonged neonatal jaundice and severe anemia requiring RBC transfusion. An intake of fava beans 48 h prior to onset of symptoms was reported. G6PD qualitative determination was compatible with this enzyme deficiency. Conclusion: G6PD deficiency can be highly variable in its clinical presentation, so it is necessary to keep it in mind during the diagnosis of hemolytic anemia at any age.

Introducción: La deficiencia de la glucosa 6-fosfato deshidrogenasa (G6PD) es el trastorno enzimático más frecuente del glóbulo rojo (GR). Tanto la disminución como la ausencia de la enzima aumentan la vulnerabilidad del GR al estrés oxidativo provocado por algunos fármacos o la ingesta de habas. Sus manifestaciones clínicas más frecuentes son hemolisis aguda, hemolisis crónica, hiperbilirrubinemia neonatal, y una forma asintomática. Objetivo: Presentar el caso de un niño que debutó como crisis hemolítica debida a favismo. Caso clínico: Varón 2 años 7 meses con antecedente de hiperbilirrubinemia en el período neonatal sin causa evidente, sin historia familiar de anemia hemolítica ni de consanguinidad paterna. Debutó con un cuadro de ictericia y anemia severa que requirió transfusión de GR. Como antecedente anamnéstico se detectó la ingesta de habas 48 h previo al inicio de los síntomas. La determinación cualitativa de G6PD fue compatible con deficiencia de esta enzima. Conclusión: La deficiencia de G6PD puede ser muy variable en su expresión clínica, por lo cual es necesario tenerla presente dentro del diagnóstico diferencial de las anemias hemolíticas a toda edad.

Triagem neonatal de deficiência de glicose-6-fosfato desidrogenase e prevalência das mutações G202A (G6PD A-) e C563T (G6PD Mediterrâneo) em Mato Grosso/Brasil / Neonatal Screening for glucose-6-phosphate dehydrogenase deficiency and prevalence of G202A (G6PD A-) and C563T (G6PD mediterranean) mutations in Mato Grosso / Brazil

Objetivos: A deficiência de glicose-6-fosfato desidrogenase (G6PD) está associada a um maior risco de encefalopatia bilirrubínica e de crise hemolítica aguda grave desencadeada por drogas como a primaquina e a dapsona. Conhecer a prevalência dessa deficiência enzimática em área onde a malária e a hanseníase ainda estão presentes e conhecer a prevalência das principais mutações traz subsídios para planejamento de estratégias com vistas à redução de riscos associados a esta deficiência enzimática. Métodos: Estudo descritivo transversal conduzido em uma região do centro-oeste do Brasil. Exame de triagem para deficiência de G6PD foi realizado em 3573 recémnascidos. Exame confirmatório foi necessário em 188 crianças triadas como possíveis portadores de deficiência. Nas crianças em que foi confirmada a deficiência de G6PD foi feita pesquisa das mutações G202A (G6PD A-) e C563T (G6PD Mediterrâneo) por PCR. Resultados: A deficiência de G6PD foi confirmada em 63 crianças, sendo 60 meninos (95,2%) e três meninas (4,8%). O percentual de exames falso-positivos na fase de triagem foi de 66,5%, estando o percentual de falso-positivos associado à temperatura e tempo de transporte das amostras. Entre as crianças que confirmaram deficiência de G6PD, foi mais frequente a história de anemia em familiares e de icterícia neonatal. Houve associação entre hematócrito baixo e deficiência enzimática, mas não com hemoglobina, contagem de reticulócitos ou neutrófilos. A prevalência da deficiência de G6PD (IC95%) foi de 1,76% (1,37; 2,24) entre os recém-nascidos triados e de 3,34% entre os meninos (2,58; 4,25). A mutação C563T não foi identificada em nenhuma criança, mas a mutação G202A estava presente em 58 crianças - 92,06% (IC95%: 83,29 - 97,03): 56/60 meninos e em 2/3 meninas homozigotas. Foi identificado um menino com Kernicterus portador da mutação G202A em hemizigose. Conclusão: O elevado percentual de falso-positivos na etapa de triagem, o tempo necessário entre coleta...

Objective: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is associated with an increased risk of bilirubin encephalopathy in neonates and acute hemolytic crisis triggered by drugs such as primaquine and dapsone. In an area where malaria and Hansen's disease are still present, knowing the prevalence of this enzyme defect and determining the prevalence of major mutations is important for planning strategies for reducing the risks associated with this enzyme deficiency. Methods: Sectional study was conducted in a Midwestern region of Brazil. Screening for G6PD deficiency was performed in 3,573 neonates. Confirmatory tests were necessary for 188 positively screened children. After confirmation, PCR investigation was utilized to identify the mutations. Results: G6PD deficiency was confirmed in 63 children: 60 boys (95.2%) and 3 girls (4.8%). The percentage of false-positive cases in the screening phase, 66.5% and was associated with the temperature and transportation time of the samples. Family history of anemia and jaundice was more frequent among the children with confirmed G6PD deficiency. An association between a low hematocrit and enzyme deficiency was observed. However, there was no association with hemoglobin reticulocyte or neutrophils counts. The prevalence of G6PD deficiency (CI95%) was 1.76% (1.37; 2.24) among all screened neonates and 3.34% (2.58; 4.25) among male children. The C563T mutation was not identified in any child. The G202A mutation was present in 58 children - 92.06% (CI95%: 83.29 - 97.03), 56/60 boys and 2/3 homozygous girls. One boy with a hemizygous G202A mutation was identified as having Kernicterus. Conclusion: The high percentage of false-positive results when first screening for G6PD deficiency; the long delay time between the test and result; along with the high cost of the this screening test, are all factors that do not support adding this test to the already established Brazilian neonatal screening programs. The prevalence...

Preliminary report on neonatal screening for congenital hypothyroidism, congenital adrenal hyperplasia and glucose-6-phosphate dehydrogenase deficiency: a chandigarh experience.

Objective To establish newborn screening in Indian scenario that could lay a framework for future such initiatives. Three disorders namely, congenital hypothyroidism (CH), congenital adrenal hyperplasia (CAH) and glucose-6- phosphate dehydrogenase deficiency (G-6-PDD) were selected for a preliminary study for newborn screening. Methods Heel-prick blood samples were collected from liveborn neonates at 24–48 h of birth as a part of a screening program after prior written consent from the parents. Blood levels of glucose-6-phosphate-dehydrogenase enzyme (G-6- PD), thyroid-stimulating hormone (TSH) and 17-α-OH progesterone (17-OHP) were measured using DELFIA time resolved fluoroimmunoassay. Results Six thousand eight hundred and thirteen (6,813) neonates (86.3%), out of a total of 7,893 live births in our institute during the period May’2007 through July’2009, were screened for CAH, CH and G6PD deficiency. Major reason for missing samples was early discharge of the neonates and admission to the neonatal intensive care unit. G-6-PD deficiency was confirmed in 61 cases, congenital hypothyroidism (CH) in 2 cases and congenital adrenal hyperplasia (CAH) in 1 neonate, accounting for an incidence of 1/112 for G-6-PDD, 1/ 3400 for CH and 1/6813 for CAH. Conclusions Preliminary data on prevalence of various genetic disorders viz. G-6-PDD, CH and CAH in the population of this region revealed that G-6-PDD is most prevalent disorder followed by CH and CAH. More efforts need to be undertaken to create awareness and emphasis on significance of preventive testing to make screening a successful program in India.

Epidemiological, clinical and laboratory profile of glucose-6-phosphate dehydrogenase deficiency in the middle and north of Iraq: a comparative study

This study determined the epidemiological, clinical and laboratory profile of glucose-6-phosphate dehydrogenase [G6PD] deficiency in Baghdad [central Iraq] and compared it with previous data from Mosul [northern Iraq]. We reviewed the records of 156 under-5-year-olds with G6PD deficiency admitted to 3 hospitals in Baghdad over a 6-year period. A preponderance of males was noted in both Baghdad and Mosul [1.6:1 and 3.4:1 respectively]. Family history of G6PD deficiency was positive in 19.2% of patients in Baghdad and 13.6% in Mosul. A majority of patients in Baghdad [69.2%] and Mosul [76.1%] showed haemolysis within 1-3 days of exposure to noxious agents. Similarities in the profiles from Baghdad and Mosul suggest that there are similar G6PD variants and similar exposure to precipitating agents

Neonatal screening program for G6PD deficiency in India: Need and feasibility.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a common genetic disorder affecting approximately 400 million people worldwide. In India, 390,000 children are born annually with this disorder causing significant morbidity and mortality in childhood. A National Neonatal Screening program for presumptive screening of all neonates using modified Formazan ring test method could be introduced. The test requires blood sample obtained using simple heel prick in the first 48 hours of life, and can be carried out using basic laboratory equipment and reagents. The screening program could be introduced in all institutional deliveries at tertiary hospitals in the major metropolitan cities and then gradually scaled up to cover institutional deliveries over the entire country. After field trials, the program can be expanded to cover home deliveries as well. Increased funding for the health sector under the National Rural Health Mission can provide the required financial support to the program.

Changes in incidence and sex ratio of glucose-6-phosphate dehydrogenase deficiency by population drift in Taiwan.

We analyzed data from a single screening center in Taiwan from January 1, 1996 to December 31, 2005 to evaluate the change in incidence and female to male ratio of G6PD deficiency. During the study period, 1,211,632 of 2,667,922 (45.41%) neonates delivered in Taiwan were screened at the National Taiwan University Hospital. Of these, 21,997 neonates (1.82%) were confirmed to have G6PD deficiency. The annual incidence has decreased since 2002, from 1.94% to 1.61%. During this period, the male to female ratio in the screened population was 1.091 (range 1.073-1.098), the incidences in male and female neonates were 2.81% (2.57-3.07%), and 0.7% (0.45-0.95%), respectively. The change in sex ratio of the disease was unrelated to the change in incidence. During 2000-2005, 15-25% of newborns were born from newly immigrated females. G6PD deficiency screening has confirmed a subtle genetic flow in Taiwan. Besides the psychosocial effects, medical issues caused by population movements should be carefully watched in the future in Taiwan.

Associação de metemoglobinemia e deficiência de glicose-6-fosfato desidrogenase em pacientes com malária tratados com primaquina / Association of methemoglobinemia and glucose-6-phosphate dehydrogenase deficiency in malaria patients treated with primaquine

Este estudo teve como objetivo verificar a ocorrência de metemoglobinemia em indivíduos deficientes da glicose-6-fosfato desidrogenase durante o tratamento da infecção malárica com primaquina. Foram selecionados pacientes com diagnóstico para malária por Plasmodium vivax ou mista V+F (Plasmodium vivax + Plasmodium falciparum), Grupo 1: com 74 indivíduos com diagnóstico clínico de metemoglobinemia e Grupo 2: 161 indivíduos sem diagnóstico clínico de metemoglobinemia. Quanto à deficiência da G6PD, nos Grupos 1 e 2, houveram 51,3 por cento (38) e 8,7 por cento (14) de indivíduos enzimopênicos, respectivamente, demonstrando através de tais dados, significância estatística na associação com a metemoglobinemia somente nos indivíduos do Grupo 1 (p<0,05). A comparação da relação da metemoglobinemia à deficiência da G6PD mostrou haver uma possível associação de indivíduos enzimopênicos desenvolverem metemoglobinemia com maior freqüência.

This study had the aim of investigating occurrences of methemoglobinemia among individuals with glucose-6-phosphate dehydrogenase deficiency during treatment for malaria infection using primaquine. Patients with a diagnosis of malaria caused by Plasmodium vivax or the V+F mixture (Plasmodium vivax + Plasmodium falciparum) were selected. Group 1 consisted of 74 individuals with a clinical diagnosis of methemoglobinemia and Group 2 consisted of 161 individuals without a clinical diagnosis of methemoglobinemia. The glucose-6-phosphate dehydrogenase deficiency rates (numbers of enzymopenic individuals) in Groups 1 and 2 were 51.3 percent (38) and 8.7 percent (14) respectively. These data demonstrated a statistically significant association with methemoglobinemia only among the individuals in Group 1 (p<0.05). Investigation of the relationship between methemoglobinemia and glucose-6-phosphate dehydrogenase deficiency showed that there was a possible association such that enzymopenic individuals may develop methemoglobinemia more frequently.

frequency and age presentation of G6PD deficiency in 200 patients of hemolytic anaemia

To determine the frequency of G6PD deficiency in the etiology of anaemia and jaundice and to determine the most common age of presentation with anaemia and jaundice due to G6PD deficiency in adults. We did a hospital based study in the department of Medicine Khyber Teaching Hospital Peshawar from June 2003 to December 2003. The data of adult patients with signs and symptoms of anaemia and jaundice was collected on structured proforma. The clinical presentation and laboratory investigation results were documented. Out of 200 patients studied, 24 [12%] patients were found to be deficient in G6PD enzyme. The male to female ratio was 21:3 [87.5% and 12.5%] respectively. The age of appearance of jaundice in adults varied [most common age from 13 to 17 years]. The most common signs and symptoms were jaundice, anaemia and haemoglobinuria. All G6PD deficient patients except one recovered spontaneously when the offending precipltating factor were stopped or treated. One [0.5%] died because of rapid fall of haemoglobin and delayed recognition of the condition and subsequent blood transfusion. G6PD deficiency is not an uncommon cause of jaundice and anaemia in our patients. The jaundice due to G6PD mainly affects the adults in 2nd or 3rd decade. Therefore all the children and adults with jaundice and anaemia should be screened for G6PD status

Screening for haemoglobinopathies and G6PD deficiency among the Mizos of Mizoram: a preliminary study.

The population of North-eastern region of India is of different tribes, races and ethnic backgrounds. The study of abnormal haemoglobins and G6PD has been usefully utilized in population genetics to evaluate the nature and extent of selective forces operating in a population. Data on haemoglobinopathies and G6PD deficiency is still not available from the State of Mizoram. The present study was aimed to document the frequency of these genetic traits in the Mizos of Mizoram. Blood samples in the form of dried filter paper spots collected from 490 Mizos were subjected to haemoglobin electrophoresis in starch agar gel for detection of haemoglobin variants and fluorescent spot test was conducted for screening of G6PD deficiency. Hb E was the only haemoglobin variant detected. The prevalence of the carreer state was documented to be 1.5%. G6PD deficiency was prevalent in 17.5% of this population. The prevalence of Hb E was much lower and that of G-6PD deficiency was found to be much higher than what has been reported from most other states of the north-eastern region of India. This might point towards a different ethnic origin of this population.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency in Yogyakarta and its surrounding areas.

Glucose-6-phosphate dehydrogenase (G6PD) is one of the enzymes needed by the erythrocyte to generate ATP from ADP. Deficiency of this enzyme can lead to hemolysis of red blood cells. Being a malaria endemic area, Indonesia possibly has a high incidence of G6PD deficiency. It is estimated that 2-6% of the population are carriers. In 1996, we detected 145 neonates with G6PD deficiency using the formazan ring method. Among the males, 6.2% had moderate and 1.4% had low enzyme activity; females had enzyme activity in the normal range. Using the Sigma kit, Tashimi et al in 1995 examined 111 neonates in Yogyakarta, none of which was identified as "deficient". There was no correlation between erythrocyte hemolysis and G6PD enzyme content. Interestingly, using the same Sigma kit. Soro et al in 1994 found that among 134 individuals of Batak descent, 10 males (43.48%) and 9 females (8.11%) were G6PD deficient. These were similar to the results reported by Pramuji et al in 1995 for the people around Palembang. Since the G6PD gene is located on the X chromosome, this is a peculiar result thus further studies need to be done. In cooperation with Harvard University, Sumantri et al in 1995 described 14% as carriers. Molecular analysis among these 16 Javanese males showed the following mutations--nt563 (C->T) in 5 cases, nt1376 (G->T) in 3 cases, nt487 (G->A) in 2 cases, nt1311 (C->T) in 1 case with the remaining variants unknown.

Automated determination of glucose-6-phosphate dehydrogenase (G6PD) on a SPOTCHECK Microflow analyzer.

Glucose-6-phosphate dehydrogenase (G6PD) is the initial enzyme in the hexose monophosphate pathway of glucose metabolism. Deficiency of G6PD has been linked to increased sensitivity of red cells to hemolytic anemia due to certain oxidant drugs, infectious agents or fava beans. It is an inherited error in metabolism and has a high incidence in certain ethnic groups. Astoria-Pacific has developed an automated assay for use on the SPOTCHECK Microflow Analyzer for the semi-quantitative determination of G6PD activity in erythrocytes. After sample extraction, all assay steps are automated including reagent addition, incubation and data collection. Use of on-line dialysis removes interferences. The assay is intended primarily as a screening tool in the diagnosis and treatment of disease states associated with G6PD deficiency in newborns. G6PD in the dried blood spot is extracted and placed on the instrument. Samples are then aspirated into the system at a rate of 90 samples/hour. All other reagents are added by the SPOTCHECK Analyzer on-line during sample processing. Incubation of each sample occurs on-line at 37 degrees C, and after dialysis the NADPH reaction product is excited at 365 nm. Fluorescence is measured at 500 nm. A lack of fluorescence indicates a probable G6PD deficiency. Data reduction occurs real time through a FASPac software thus individual results are available during a run as soon as each sample analysis is complete. The Astoria-Pacific International G6PD reagent kit paired with the SPOTCHECK Microflow Analyzer provides an effective and easy to use screening tool for determining G6PD deficiency in newborns.

Quality assurance program for neonatal screening of glucose-6-phosphate dehydrogenase deficiency.

The nationwide neonatal screening of glucose-6-phosphate dehydrogenase (G6PD) deficiency in Taiwan was started on July 1, 1987. The effective collection rate has reached more than 96% of all newborns since 1993 and the overall incidence rate of G6PD deficiency was about 2%. This screening program has 3 screening centers and 18 referral hospitals, distributed around Taiwan including outlying islands. To assess the reliability of the confirmatory and screening tests, an external quality assurance (QA) program for G6PD assay was developed. For quantitative assay of G6PD activity, lyophilized quality control materials with different G6PD activities were prepared from red blood cells. For G6PD screening, quality control materials with different G6PD activities were prepared from whole blood and spotted onto the blood collecting filter paper. Periodically (1-2 months), the QC materials were sent to each of the referral hospitals and screening centers by speed post delivery. The external QA results were evaluated and compared to the median of all the reports and the reference values determined by our laboratory. Whenever an analytical system error was detected in any participating laboratory, troubleshooting was carried out either by contacting by phone or visiting in person. Twenty-one referral laboratories and 8 screening centers (3 in Taiwan, 2 in Mainland China, and one each in the Philippines, Thailand and Lebanon) participated in the QA program. Three to 5 QC specimens were sent to every participating referral laboratory for each quantitative survey. From January 1988 to June 2001, 104 QA surveys were carried out and 1,891 reports were received. Two hundred and thirty-nine (12.6%, 239/1,891) QA reports had abnormal results, attributed to clerical (13%, 31/239), experimental (17.2%, 41/239), and instrumental errors (46.4%, 111/239). Most of the experimental and instrumental errors were found in those laboratories that did not execute internal QA properly. For the screening QA program, 10 QC blood spots were delivered to every participating screening center for each survey. From March 1999 to June 2001, 15 screening surveys were performed with 111 reports received. One false negative (1/1,110) and 14 (14/1,110) false positive results were found in four (3.6%, 4/111) of the screening QA reports. The external quality assurance program proved useful for monitoring the performance of G6PD tests in referral hospitals and screening centers, and provided guidance for correcting analytical errors.

Neonatal screening in Hong Kong and Macau.

For the implementation of the neonatal screening program, the following factors have to be considered for the selection of conditions to be screened and evaluation of outcome. These include the factors pertaining to public health impact, availability and acceptability of the screening system, and other social issues involved in the implementation. In the context of Hong Kong, Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency and Congenital Hypothyroidism (CHT) have been highlighted in the early 1980s for consideration. A territory wide program for screening these conditions was started in 1984. Since then, over 99% of all newborns in Hong Kong was screened. Of these, around 70% were delivered in public hospitals, and the remaining were from private hospitals. Pre-screening education was emphasized, and 95% of pregnant ladies received information about this screening program from the Maternity and Child Health Centers run by the Department of Health, Hong Kong. For those who were born in public hospitals, the incidence of CHT was 1 in 2404 (269/646,580), while that of G6PD deficiency was 4.5% in male newborns and 0.3% in female newborns. This paper highlights details of the screening program, including its outcome evaluation. In Macau, CHT screening has not been started. Instead, G6PD deficiency screening commenced in 1977 in one of the two major hospitals where most newborns are delivered. Methodology and results of this program are presented.

Using the fluorescence spot test for neonatal screening of G6PD deficiency.

To establish the neonatal screening method of glucose-6 phosphate dehydrogenase (G6PD) deficiency, G6PD activity was measured using the fluorescence spot test (FST) using dried blood samples on filter paper. The G6PD/6PGD rate test of venous blood samples was further performed for confirmation. The positive G6PD deficiency rate was 4.2% and its detection rates were 3.7% for all neonates and 5.2% only for male newborns when FST was used for neonatal screening. Conformation rates by use of G6PD/ 6PGD ratio test for G6PD deficiency were 86.8% and 100% particularly in the severely deficient groups. Both sensitivity and specificity were very high in the severely deficient groups. FST can be used in neonatal screening of G6PD deficiency because of its high accuracy, applicability, and simplicity. Moreover, a high volume of dried blood samples on filter paper can be tested quickly. It is very favorable to diagnose and treat G6PD deficiency early in high incidence districts.

Effect of red blood cell glucose-6-phosphate dehydrogenase deficiency on patients with dengue hemorrhagic fever.

Eighty nine males aged 1-13 years diagnosed with dengue haemorrhagic fever (DHF) and admitted to the Department of Pediatrics Siriraj Hospital from March 1998 to April 2000 were included in this study. 17 cases (19.1%) had red blood cell glucose-6-phosphate dehydrogenase (G-6-PD) deficiency and 72 cases (80.9%) had normal G-6-PD enzyme activities. Most of the patients were classified as DHF grade II in severity. 3 of 17 G-6-PD deficient cases had serious complications and all of them had acute intravascular hemolysis requiring blood transfusions. One of these also had hematemesis, one had azothemia and the other one had renal failure and severe liver failure with hepatic encephalopathy. In the cases without obvious hemolytic or hepatic complications, G-6-PD deficient cases had mildly but significantly higher total birirubin and indirect bilirubin, as well as a lower hematocrit than those who had normal G-6-PD. Reticulocyte count was low during the acute phase, however, during recovery, the levels were significantly increased in both groups. In the non G-6-PD deficient group, G-6-PD enzyme levels were significantly decreased during the acute phase compared to the normal controls but rose significantly to normal levels during the recovery phase. There were no statistically significant differences in other laboratory data. All patients recovered fully from DHF. The prevalence of G-6-PD deficiency in male patients who had DHF in this study was 19.1 per cent which was higher than the prevalence in a previous study of 12 per cent in Bangkok. This may imply that G-6-PD deficient males suffer more from DHF compared to normal G-6-PD subjects.

The value of methemoglobin reduction test as a screening test for neonatal glucose 6-phosphate dehydrogenase deficiency.

Glucose 6-phosphate dehydrogenase (G-6-PD) deficiency is common in the Thai population and is the cause of neonatal hyperbilirubinemia and hemolytic anemia. This X-linked disorder is much more common in males than females. The objectives of this study were to compare the result of the screening methemoglobin reduction test (MRT) with the gold standard G-6-PD activity, and also to determine the prevalence of G-6-PD deficiency in the cord blood and blood of neonates with hyperbilirubinemia. Five hunderd and twenty two randomly selected cord blood (350 males, 172 females) and 229 peripheral blood from neonates with hyperbilirubinemia were assayed for G-6-PD enzyme activity using a WHO-recommended standard test as well as methemoglobin reduction (MR) test. The results showed that prevalence of G-6-PD deficiency from the cord blood was 11.1 per cent in males, and 5.59 per cent in females. Among newborns with neonatal jaundice, the prevalence of G-6-PD deficiency was 22.1 per cent in males and 10.1 per cent in females. MRT in cord blood G-6-PD deficiency screening had acceptable sensitivity (85.7%) and high specificity (98.1%). The sensitivity of MRT in jaundiced infants was low (60.0%) whereas the specificity was acceptable (92.1%). The negative predictive values were more than 90 per cent while the positive predictive values were low (61-65%) from both specimens. Conclusions: G-6-PD deficiency is common in the Thai population, both in males and females and can be screened from cord blood by using low cost MRT. G-6-PD deficiency contributes to 20 per cent of neonatal jaundice, and screening with MRT yields low sensitivity.