Setting the Optimal Erythrocyte Protoporphyrin Screening Decision Threshold for Lead Poisoning: A Decision Analytic Approach

PEDIATRICS ◽  
1991 ◽  
Vol 88 (1) ◽  
pp. 121-131
Author(s):  
Michael R. DeBaun ◽  
Harold C. Sox
Keyword(s):  
Lead Poisoning ◽  
Characteristic Curve ◽  
Lead Level ◽  
Blood Lead ◽  
Receiver Operator Characteristic Curve ◽  
Receiver Operator Characteristic ◽  
Decision Threshold ◽  
Erythrocyte Protoporphyrin ◽  
Positive Rate ◽  
The Relationship

Erythrocyte protoporphyrin (EP) was introduced in the 1970s as an inexpensive screening test for lead poisoning. As greater knowledge of lead poisoning has accumulated, the recommended EP level at which further evaluation for lead poisoning should be initiated has been lowered from ≥50 µg/dL to ≥35 µg/dL. The purpose of this study was to evaluate the utility of this EP threshold. A receiver operator characteristic curve was constructed to assess the relationship between the true-positive rate and false-positive rate of EP at various decision thresholds. The receiver operator characteristic curve was constructed with data from the second National Health and Nutrition Examination Survey from 1976 to 1980, which included 2673 children 6 years of age or younger who had both blood lead and EP level determinations. Decision analysis was then used to determine the optimal EP decision threshold for detecting a blood lead level ≥25 µg/dL. The receiver operator characteristic curve demonstrated that EP is a poor predictor of a blood lead level ≥25 µg/dL. At the currently recommended EP decision threshold of 35 µg/dL, the true-positive rates and false-positive rates of EP are 0.23 and 0.04, respectively. As a result of the inadequate performance of EP screening for lead poisoning, when the prevalence of lead poisoning is greater than 8%, there is no EP decision threshold that optimizes the relationship between the cost of screening normal children and the benefit of detecting lead-poisoned children. Erythrocyte protoporphyrin measurement is not sufficiently sensitive to be recommended uniformly as a screening test for lead poisoning.

Effects of Calcium Disodium Versenate (CaNa2EDTA) Chelation in Moderate Childhood Lead Posioning

PEDIATRICS ◽  
1993 ◽  
Vol 92 (2) ◽  
pp. 265-271
Author(s):  
Morri E. Markowitz ◽  
Polly E. Bijur ◽  
Holly Ruff ◽  
John F. Rosen
Keyword(s):  
Lead Poisoning ◽  
Chelation Therapy ◽  
Controlled Trial ◽  
Lead Level ◽  
Chelating Agent ◽  
Blood Lead ◽  
Erythrocyte Protoporphyrin ◽  
Bone Lead ◽  
Sustained Reduction ◽  
The Relationship

Background. For children with asymptomatic moderate lead poisoning (Blood lead level [BPb] 25 to 55 µg/dL [1.21 to 2.66 µmol/L]), treatment with the chelating agent calcium disodium versenate (CaNa2EDTA) is recommended for all those children with a BPb level >45 µg/dL (2.17 µmol/L) and for those with a BPb level of 25 to 44 µg/dL (1.21 to 2.13 µmol/L) who also have a positive lead mobilization test. However, controlled studies demonstrating its efficacy at inducing a sustained reduction in BPb level or lead-related toxicity have not been performed in children with moderate lead poisoning. This study assesses the relationship between CaNa2EDTA chelation and measures of lead burden and toxicity in children with moderate lead poisoning. Methods. Two hundred one children with moderate lead poisoning were enrolled. Sequential changes in BPb concentrations, bone lead level as measured by Lα-x-ray fluorescence, and lead-induced toxicity as assessed by erythrocyte protoporphyrin levels were determined over a 7-week period. From this group, children with a positive lead mobilization test received CaNa2EDTA chelation therapy. Results. Children with positive lead mobilization tests had on average higher initial BPb, bone lead, and erythrocyte protoporphyrin concentrations. The chelated children decreased approximately 4.7 µg/dL (0.23 µmol/L), 41 corrected net counts, and 24 µg/dL (0.46 µmol/L) more than the unchelated children on BPb, bone lead, and erythrocyte protoporphyrin values, respectively. However, children with higher initial levels decreased the most, whereas children with lower initial levels showed the least decline, with or without treatment. When the initial values on the measures were controlled analytically, or when subgroups matched on initial levels were compared, there were no significant differences between the chelated and unchelated children. Conclusions. The apparent effectiveness of CaNa2EDTA at reducing lead burden and toxicity is no longer observed when the pretreatment levels are considered. The findings suggest that sufficient doubt about CaNa2EDTA efficacy now exists to warrant a randomized controlled trial of chelation therapy in moderately lead-poisoned children. However, until such studies are performed, it would be premature to withhold chelation treatment on the basis of this study alone.

AVALIAÇÃO DE UM INSTRUMENTO DE MENSURAÇÃO DE MORBIDADE PSÍQUICA: ESTUDO DE VALIDAÇÃO DO SELF-REPORTING QUESTIONNAIRE (SRQ-20)

1970 ◽  
Vol 34 (3) ◽  
pp. 544 ◽  
Author(s):  
Kionna Oliveira Bernardes Santos ◽  
Tânia Maria de Araújo ◽  
Paloma de Sousa Pinho ◽  
Ana Cláudia Conceição Silva
Keyword(s):  
Characteristic Curve ◽  
Receiver Operator Characteristic Curve ◽  
Clinical Interview ◽  
Receiver Operator Characteristic ◽  
Interview Schedule ◽  
Para Determinar ◽  
Self Reporting Questionnaire

O Self-Reporting Questionnaire (SRQ-20), desenvolvido pela Organização Mundial de Saúde, tem sido utilizado para mensuração de nível de suspeição de transtornos mentais em estudos brasileiros, especialmente em grupos de trabalhadores. O objetivo deste estudo foi avaliar o desempenho do SRQ-20, com base em indicadores de validade (sensibilidade, especificidade, taxa de classificação incorreta e valores preditivos), e determinar o melhor ponto de corte para classificação dos transtornos mentais comuns na população estudada. O estudo incluiu 91 indivíduos selecionados aleatoriamente de um estudo de corte transversal realizado com população residente em áreas urbanas de Feira de Santana (BA). Entrevistas clínicas, realizadas por psicólogas, utilizando o Revised Clinical Interview Schedule (CIS-R), foi adotada como padrão-ouro. Na avaliação do desempenho do SRQ-20 foram estimados indicadores de validade (sensibilidade e especificidade). A curva Receiver Operator Characteristic Curve (ROC) foi utilizada para determinar o melhor ponto de corte para classificação de suspeitos/não suspeitos. O ponto de corte de melhor desempenho foi de 6/7 para a população investigada, revelando desempenho razoável com área sob a curva de 0,789. Os resultados indicam que o SRQ-20 possui característica discriminante regular.

scholarly journals Haemoconcentration as a predictor of severity in acute pancreatitis

2016 ◽  
Vol 4 (1) ◽  
pp. 3-7
Author(s):  
Tanka Prasad Bohara ◽  
Dimindra Karki ◽  
Anuj Parajuli ◽  
Shail Rupakheti ◽  
Mukund Raj Joshi
Keyword(s):  
Acute Pancreatitis ◽  
Pearson Correlation ◽  
Characteristic Curve ◽  
Scoring Systems ◽  
Cost Effective ◽  
Receiver Operator Characteristic Curve ◽  
First Episode ◽  
P Value ◽  
Receiver Operator Characteristic ◽  
Chi Square

Background: Acute pancreatitis is usually a mild and self-limiting disease. About 25 % of patients have severe episode with mortality up to 30%. Early identification of these patients has potential advantages of aggressive treatment at intensive care unit or transfer to higher centre. Several scoring systems are available to predict severity of acute pancreatitis but are cumbersome, take 24 to 48 hours and are dependent on tests that are not universally available. Haematocrit has been used as a predictor of severity of acute pancreatitis but some have doubted its role.Objectives: To study the significance of haematocrit in prediction of severity of acute pancreatitis.Methods: Patients admitted with first episode of acute pancreatitis from February 2014 to July 2014 were included. Haematocrit at admission and 24 hours of admission were compared with severity of acute pancreatitis. Mean, analysis of variance, chi square, pearson correlation and receiver operator characteristic curve were used for statistical analysis.Results: Thirty one patients were included in the study with 16 (51.61%) male and 15 (48.4%) female. Haematocrit at 24 hours of admission was higher in severe acute pancreatitis (P value 0.003). Both haematocrit at admission and at 24 hours had positive correlation with severity of acute pancreatitis (r: 0.387; P value 0.031 and r: 0.584; P value 0.001) respectively.Area under receiver operator characteristic curve for haematocrit at admission and 24 hours were 0.713 (P value 0.175, 95% CI 0.536 - 0.889) and 0.917 (P value 0.008, 95% CI 0.813 – 1.00) respectively.Conclusion: Haematocrit is a simple, cost effective and widely available test and can predict severity of acute pancreatitis.Journal of Kathmandu Medical College, Vol. 4(1) 2015, 3-7

Lead Poisoning: Twenty Years After

PEDIATRICS ◽  
1993 ◽  
Vol 92 (3) ◽  
pp. 505-505
Author(s):  
HENRIETTA SACHS ◽  
DONALD I. MOEL
Keyword(s):  
Disease Control ◽  
Lead Poisoning ◽  
Blood Lead Level ◽  
Scientific Evidence ◽  
Lead Level ◽  
Blood Lead ◽  
Neurobehavioral Development ◽  
Long Term Follow Up

To the Editor.— In October 1991, the Centers for Disease Control decreased the blood lead level PbB) from 25 to 10 µg/dL and designated it as abnormal because of "overwhelming and compelling scientific evidence"1 that 10 µg/dL is associated with adverse neurobehavioral development. We have evidence to the contrary, obtained in a long-term follow-up of severely lead-poisoned children whom we treated before 1972 for PbBs between 80 and 470 µg/dL (mean, 150.3 ± 77.1 µg/dL); their mean age was 28 months.

Too Much Lead, Too Little Iron

PEDIATRICS ◽  
1988 ◽  
Vol 82 (3) ◽  
pp. 395-395
Author(s):  
MARGARET CLARK
Keyword(s):  
Public Health ◽  
Iron Deficiency ◽  
Lead Poisoning ◽  
Predictive Value ◽  
Blood Lead ◽  
Blood Lead Levels ◽  
The Public ◽  
Erythrocyte Protoporphyrin ◽  
Lead Levels

In Reply.— We appreciate the work of Carraccio et al which confirms our findings that the anemia found in children with lead poisoning results from coexistent iron deficiency. The discrepancy between the two studies concerning the predictive value of blood lead in elevations of erythrocyte protoporphyrin bears further exploration. What is striking, however, is that in both series more than 50% of the variability in erythrocyte protoporphyrin remains unexplained. Now the public health focus is on detecting children with low blood lead levels—before even subtle CNS damage has occurred.

scholarly journals Nephelometric determination of carbohydrate deficient transferrin

1996 ◽  
Vol 42 (4) ◽  
pp. 551-557 ◽  
Author(s):  
F Schellenberg ◽  
M Martin ◽  
E Cacès ◽  
J Y Bénard ◽  
J Weill
Keyword(s):  
Sialic Acid ◽  
Characteristic Curve ◽  
Anion Exchange Chromatography ◽  
Receiver Operator Characteristic Curve ◽  
Exchange Chromatography ◽  
Treatment Center ◽  
Serum Transferrin ◽  
Receiver Operator Characteristic ◽  
Carbohydrate Deficient Transferrin

Abstract We describe a technique for measuring carbohydrate-deficient transferrin (CDT) in serum. Serum transferrin fractions are separated by anion-exchange chromatography on microcolumns. Sialic acid-deficient transferrin fractions are collected in the eluate, and transferrin is then quantified by a rate-nephelometric technique. Imprecision (CV) was 4-5% within-run and 7-9% between runs (n = 15). Comparison with an isoelectric focusing-immunofixation method for transferrin index (x) yielded y = 761x + 7, Sy/x = 39 mg/L. Assay of sera from 90 abstainers or moderate consumers of alcohol showed that 81 (90%) had CDT concentrations between 30 and 70 mg/L. Among 74 alcoholics admitted to an alcohol treatment center, 54 (73%) had CDT > 70 mg/L, i.e., the diagnostic sensitivity was 73% at a specificity of 90% (area under receiver-operator characteristic curve = 0.891).

scholarly journals Lead Toxicity due to Ingestion of Lead-Contaminated Opium in a Patient Presenting with Motor Neuropathy and Upper Limb Paresis: A case report

2019 ◽  
Vol 18 (4) ◽  
pp. 529 ◽  
Author(s):  
Seyed M. M. Mirzaei ◽  
Ayob Akbari ◽  
Omid Mehrpour ◽  
Nasim Zamani
Keyword(s):  
Nervous System ◽  
Case Report ◽  
Lead Poisoning ◽  
Chelation Therapy ◽  
Lead Level ◽  
Lead Toxicity ◽  
Blood Lead ◽  
Motor Neuropathy ◽  
Upper Limbs ◽  
Gastrointestinal Complications

Opium users may present with central or peripheral nervous system-related symptoms, gastrointestinal complications and anaemia; in such cases, lead poisoning should be suspected and chelation therapy initiated as soon as possible. We report a 64-year-old male patient with a 20-year history of opium addiction who was referred to the Imam Reza Hospital, Birjand, Iran, in 2017 with severe motor neuropathy and paresis in both upper limbs. His primary symptoms were generalised weakness, abdominal and bone pain, constipation and lower limb paraesthesia that had started several months prior. In addition, he reported severe progressive bilateral paresis of the upper limbs of one month’s duration. A diagnosis of lead poisoning was confirmed by a blood lead level of 140 μg/dL. The patient underwent chelation therapy after which he improved significantly. At a one-year follow-up visit, he was neurologically intact and symptom-free.Keywords: Opium Dependence; Lead Poisoning; Lead-Induced Nervous System Diseases; Paresthesia; Case Report; Iran.

scholarly journals Against lead poisoning: effectiveness of housing first and counselling in the home

2019 ◽  
Vol 29 (Supplement_4) ◽  
Author(s):  
R Laporte ◽  
H Barberin de Barberini ◽  
E Jouve ◽  
K Hadji ◽  
S Gentile
Keyword(s):  
Lead Poisoning ◽  
Lead Exposure ◽  
Blood Lead Level ◽  
Lead Level ◽  
Blood Lead ◽  
Housing First ◽  
Blood Lead Levels ◽  
Stable Housing ◽  
Lead Levels

Abstract Background Removing lead sources is the main measure against child lead poisoning. Medical treatment is ineffective for most mild cases and particularly against long-term complications in neurological development. However, the effectiveness of interventions to eliminate sources of lead exposure has not been fully established, mainly because of the diversity of situations. The objective of this study was to determine the influence of several interventions (housing counselling, rehabilitation and relocation) on blood lead levels in two situations (stable unhealthy housing with old flaked lead paints, slums with family recycling practices by incineration). Methodology A historical cohort of lead poisoning in children has been established in Marseille, France. Medical follow-up followed national guidelines. Environmental interventions followed legal procedures, where available. In slums, counselling was adapted to the exposure. A generalized mixed model was developed to study the kinetics of blood lead levels after the interventions. Results 151 children were included; age = 5.4 (SD = 7.8) years; 85 (56%) lived in stable unhealthy housing, others lived in slums. Medical follow-up included 492 blood lead levels. For children living in stable unhealthy housing, blood lead level decrease was significantly associated with every intervention: housing counselling, rehabilitation and relocation (respectively p < 0.005; p < 0.05 and p < 0.005). For children living in slums, blood lead level decrease was only associated with relocation in a stable housing (p < 0.005). Conclusions Several interventions are effective to decrease blood lead levels in unhealthy housing. In slums, access to a stable housing first is a prerequisite for any intervention against child lead poisoning, even when related to family practices. Key messages In stable unhealthy housing, several interventions against lead exposure can be effective to raise a strategy. But, environmental health and access to housing first needs to be addressed for their implementation.

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