Newborn sickle cell screening in a region of Western New York State

Expression Pattern of HIF-1α and VEGF Supports Circumferential Application of Scatter Laser for Proliferative Sickle Retinopathy

Purpose

Retinal vascular occlusions in sickle cell anemia patients cause tissue ischemia and the release of angiogenic mediators that promote the development of retinal neovascularization, initiating proliferative sickle retinopathy (PSR). Laser photocoagulation (LPC) has emerged as the most common treatment for PSR. Nonetheless, only two randomized controlled clinical trials have evaluated the use of LPC for PSR, and both failed to definitively demonstrate efficacy of this approach. This may be due to a lack of knowledge regarding the appropriate location for placement of laser coagulations in PSR eyes. To help address this question, we examined the expression of hypoxia-inducible factor (HIF)-1α and vascular endothelial growth factor (VEGF) in PSR eyes.

Methods

The expression pattern of HIF-1α and VEGF in PSR (n = 5) and control (n = 3) eyes was examined by immunohistochemistry in different retinal regions defined by the presence or absence of retinal vessels.

Results

Hypoxia-inducible factor 1α and VEGF were expressed in the inner retina of 5/5 untreated PSR eyes adjacent to retinal neovascularization; expression of HIF-1α was not detected (and VEGF only lightly detected) in normal retinal and choroidal vasculature of 3/3 control eyes. Hypoxia-inducible factor 1α and VEGF were strongly expressed in retinal cells within avascular (nonperfused) retina, anterior to the boundary between perfused and nonperfused retina, as well as in posterior ischemic retina in the presence or absence of neovascular sea fans.

Conclusions

If the goal of LPC in PSR is to quench the expression of HIF-1–driven angiogenic mediators, our results support broad application of peripheral laser for its treatment.

Impact of prematurity and immigration on neonatal screening for sickle cell disease

Background

Others have described a relationship between hemoglobin A levels and gestational age, gender and ethnicity. However, studies are needed to determine normal cut-off points considering these factors. To address this issue we designed a study to determine the percentiles of normality of neonatal hemoglobin A levels taking these factors into account.

Methods

This cross-sectional study involved 16,025 samples for sickle cell disease screening in the province of Alicante, Spain, which has a high immigration rate. The primary variable was hemoglobin A, and the secondary variables were gender, gestational age (preterm and full term) and maternal origin (Spain, the rest of Europe, North Africa, Sub-Saharan Africa, Latin America and Asia). Percentiles of normality (1 and 99) were obtained by origin, gender and gestational age using quantile regression models and bootstrap samples. The association between these percentiles of normality and altered levels (≥1%) of hemoglobin E was analyzed. We obtained the percentiles of normality (1 and 99) for each maternal origin, gender and gestational age.

Results

Of a total of 88 possible E carriers, 65 had above-normal hemoglobin A levels (74%). The levels of normality for hemoglobin A varied greatly according to the maternal origin and gestational age.

Conclusion

With the levels of normality that we established it is possible to discard samples with unrecorded blood transfusions. Our methodology could be applied to other diseases in the neonatal screening.

Identification and management of sickle cell trait by young physicians

BACKGROUND

Sickle cell disease (SCD) is found in many ethnic groups, with the highest prevalence of heterozygote ' carriers (sickle cell trait [SCT]) in African Americans. SCT is associated with an increased risk of fatal exertional heat illness, renal papillary necrosis, and splenic infarction. Since 2006, all infants born in the United States are required to be screened for hemoglobinopathies as part of newborn screening (NBS). In 2010, as part of a legal settlement, the National Collegiate Athletic Association (NCAA) implemented SCT screening in division I athletes.

METHODS

Members of the American Academy of Pediatrics (AAP) Section on Young Physicians were sent up to 4 e-mail survey requests to evaluate SCT education during residency, current NBS follow-up practice, and awareness of the NCAA policy. Descriptive statistics and chi2 analyses were performed.

RESULTS

Of 871 eligible participants, 355 (41%) completed the survey. Respondents were 70% female, 71% white, and 79% general pediatricians. Most had experience with SCD during residency and had been taught about the medical and reproductive implications of SCT. Virtually all pediatricians report SCT to families when identified during NBS, but only 59% order confirmatory testing (e.g., hemoglobin electrophoresis) to verify status. While 93% counsel about reproductive implications of SCT, only 71% counsel about other medical implications. Only 27% were aware of the NCAA policy.

DISCUSSION

Despite formal SCT education, a significant number of pediatricians do not verify NBS results or counsel about the medical implications of SCT. More comprehensive AAP guidelines about SCT are needed and must be incorporated into residency education.

A review of clinical profile in sickle cell traits

Sickle cell trait is not usually regarded as a disease state because it has complications that are either uncommon or mild. Nevertheless, under unusual circumstances, serious morbidity or mortality can result from complications related to polymerization of deoxy-hemoglobin S. A previous study was earlier conducted to study Sickle cell traits and it revealed that there was enhanced lipid per oxidation along with imbalance in the pro-oxidant and antioxidant status in patients with sickle cell anaemia. Moreover, sickle cell traits present with varied problems including increased urinary tract infection in women, gross hematuria, complications of hyphema, splenic infarction with altitude hypoxia or exercise, life-threatening complications of exercise etc. Renal medullary carcinoma in the young, early onset of end stage renal, as well as disease from autosomal dominant polycystic kidney disease are other well-known occurrences in sickle cell traits. In view of the above facts, this article aims to review the literature to analyze the health status in sickle cell traits.

Sickle cell disease incidence among newborns in New York State by maternal race/ethnicity and nativity

PURPOSE

Sickle cell disease is estimated to occur in 1:300-400 African-American births, with higher rates among immigrants from Africa and the Caribbean, and is less common among Hispanic births. This study determined sickle cell disease incidence among New York State newborns stratified by maternal race/ethnicity and nativity.

METHODS

Newborns with confirmed sickle cell disease born to New York State residents were identified by the New York State newborn screening program for the years 2000-2008 and matched to birth records to obtain birth and maternal information. Annual incidence rates were computed and bivariate analyses were conducted to examine associations with maternal race/ethnicity and nativity.

RESULTS

From 2000 to 2008, 1,911 New York State newborns were diagnosed with sickle cell disease and matched to the birth certificate files. One in every 1,146 live births was diagnosed with sickle cell disease. Newborns of non-Hispanic black mothers accounted for 86% of sickle cell disease cases whereas newborns of Hispanic mothers accounted for 12% of cases. The estimated incidence was 1:230 live births for non-Hispanic black mothers, 1:2,320 births for Hispanic mothers, and 1:41,647 births for non-Hispanic white mothers. Newborns of foreign-born non-Hispanic black mothers had a twofold higher incidence of sickle cell disease than those born to US-born non-Hispanic black mothers (P < 0.001).

CONCLUSION

This study provides the first US estimates of sickle cell disease incidence by maternal nativity. Women born outside the United States account for the majority of children with sickle cell disease born in New York State. Such findings identify at-risk populations and inform outreach activities that promote ongoing, high-quality medical management to affected children.

Exploring Family Communication About Sickle Cell Disease in Adolescence

Sickle cell disease (SCD) is a lifelong disorder that involves progressive organ damage and requires ongoing medical attention to prevent and treat episodic acute complications. Children with SCD need ongoing monitoring and extra attention that may be stressful to family members. Communication within families can help resolve family stress and may be associated with medical follow-up and management of SCD. Focus groups were conducted with 12 African American families to explore the communication that occurred within and outside of the family from the perspectives of adolescents with SCD, siblings, and parents. Factors that influence family communication were explored. The extended family was an important social network and resource to adolescents, siblings, and parents. Family member knowledge of SCD was an important factor that influenced communication about SCD; adolescents and parents communicated more easily than siblings and also reported having more knowledge of SCD than siblings. Future research focusing on the knowledge of immediate and extended family members and their recognition of their contribution to the child with SCD is recommended.

Sickle cell disease: the need for a public health agenda

Sickle cell disease (SCD) is a collection of inherited blood disorders that affect a substantial number of people in the U.S., particularly African Americans. People with SCD have an abnormal type of hemoglobin, Hb S, which polymerizes when deoxygenated, causing the red blood cells to become misshapen and rigid. Individuals with SCD are at higher risk of morbidity and mortality from infections, vaso-occlusive pain crises, acute chest syndrome, and other complications. Addressing the public health needs related to SCD is an important step toward improving outcomes and maintaining health for those affected by the disorder. The objective of this study was to review public health activities focusing on SCD and define the need to address it more comprehensively from a public health perspective. We found that there has been some progress in the development of SCD-related public health activities. Such activities include establishing newborn screening (NBS) for SCD with all states currently having universal NBS programs. However, additional areas needing focus include strengthening surveillance and monitoring of disease occurrence and health outcomes, enhancing adherence to health maintenance guidelines, increasing knowledge and awareness among those affected, and improving healthcare access and utilization. These and other activities discussed in this paper can help strengthen public health efforts to address SCD.

Exploring parent-sibling communication in families of children with sickle cell disease

BACKGROUND

Communication within families of children with sickle cell disease is important yet has not been adequately investigated.

METHODS

Focus group interviews were conducted with parents of children with sickle cell disease to explore parent-sibling communication about sickle cell disease.

RESULTS

Communication was influenced by attributes and behaviors of the parent, the child with sickle cell disease, and the sibling; extended family, neighbors, friends, and church members or social networks; and available, accessible resources related to the child's health, child's school, and parent employment. Outcomes that influenced and were influenced by factors within and outside the parent-sibling dyad and nuclear family included parent satisfaction, parent roles, family intactness, and status attainment.

CONCLUSIONS

These findings support previous research with African-American families and expand our views of the importance of educating parents, family members, and others about sickle cell disease. The findings suggest a need to explore sibling perception of this communication, parent and sibling perception of the impact of frequent hospitalizations and clinic visits on the sibling and family, and variations within families of children with sickle cell disease.

Evaluation of the validity and utility of genetic testing for rare diseases

The conventional criteria for evaluating genetic tests include analytic validity, clinical validity, and clinical utility. Analytical validity refers to a test's ability to measure the genotype of interest accurately and reliably. Clinical validity refers to a test's ability to detect or predict the clinical disorder or phenotype associated with the genotype. Clinical utility of a test is a measure of its usefulness in the clinic and resulting changes in clinical endpoints. In addition, the utility to individuals and families of genomic information, or personal utility, should be considered. This chapter identifies methodological and data issues involved in assessing each type of validity or utility. The validity and utility of a test must be considered in a specific context, which include diagnostic testing, newborn screening, prenatal carrier screening, and family or cascade screening. Specific rare disorders addressed include cystic fibrosis, fragile X syndrome, Duchenne and Becker muscular dystrophy, spinal muscular atrophy, Huntington disease, as well as cancer associated with BRCA mutations.