Adverse childhood experiences in children and adolescents with sickle cell disease: A retrospective cohort study.

BACKGROUND: Adverse childhood experiences (ACEs) are linked to poor health outcomes; however, the relationship between ACEs and health outcomes among children and adolescents with sickle cell disease (SCD) has limited documentation in the published literature. PROCEDURE: This retrospective cohort study involved 45 children and 30 adolescents. Participants were screened using the Center for Youth Wellness ACE Questionnaire. Parents completed the questionnaire for children. Adolescents provided self-report. ACEs were treated as continuous and categorical scales: 0-1 verus ≥2 original ACEs (individual and/or familial level); 0-1 versus ≥2 additional ACEs (community level); and 0-3 versus ≥4 expanded ACEs (original + additional). Pain and acute chest syndrome events were compared using Wilcoxon rank-sum tests, and correlated with cumulative ACE scores using Spearman's correlation. Multivariable models were fitted to examine the association between ACEs and pain/acute chest syndrome. RESULTS: The cumulative number of original ACEs positively correlated with acute chest syndrome events (rho = .53, p = .003) and pain (rho = .40, p = .028) among adolescents. Adolescents with ≥2 versus 0-1 original ACEs had a higher number of acute chest syndrome events (4.9 ± 2.6 vs. 1.6 ± 2.2, p = .002); however, this association was confounded by asthma. Acute chest syndrome events and hospitalizations for pain did not differ among child ACE groups. Emergency department (ED) pain visits were higher among children with ≥4 versus 0-3 expanded ACEs (1.6 ± 2.8 vs. 3.3 ± 3.2, p = .042), even after controlling for SCD genotype, asthma, disease-modifying treatment, and follow-up years (p = .027). CONCLUSION: ACEs are linked to increased morbidity among children and adolescents with SCD. Prospective studies are needed to further understand this relationship and test ACE-protective remedies.

Acute chest syndrome in pediatric sickle cell disease: Associations with racial composition and neighborhood deprivation.

BACKGROUND: Acute chest syndrome (ACS) is the leading cause of death for children with sickle cell disease (SCD). Recurrent ACS has detrimental effects on pulmonary health and health care costs. Neighborhood characteristics affect the outcomes of many pediatric chronic diseases, but their role in SCD is not well studied. In this study, we investigated the effects of area-level socioeconomic deprivation and racial composition on the recurrence of ACS. STUDY DESIGN: We performed a retrospective cross-sectional analysis of clinical data from a large pediatric SCD center. Patients' residential addresses were geocoded and linked to a composite area deprivation index (ADI) and percent African American population at the level of Census block groups. The association of recurrent ACS with neighborhood characteristics was evaluated using logistic regression analysis. RESULTS: The sample included 709 children with SCD. Residence in a socioeconomically deprived neighborhood was associated with 27% less risk of recurrent ACS, and residence in a predominantly African American neighborhood was associated with 41% less risk of ACS recurrence. The racial composition explained the protective effect of living in a high-deprivation area after adjusting for sociodemographic and clinical covariates. Demographic and clinical factors associated with recurrent ACS included older age, male gender, asthma, hydroxyurea use, and chronic transfusion therapy. CONCLUSIONS: This is the first study to report a protective effect of residing in a predominantly African American community for ACS recurrence. Further prospective studies are needed to confirm the association and to understand the mechanisms of such relationship.

The burden of respiratory syncytial virus infections among children with sickle cell disease.

BACKGROUND: Although respiratory syncytial virus (RSV) is the leading cause of pediatric lower respiratory tract infections, the burden of RSV in children with sickle cell disease (SCD) is unknown. METHODS: We conducted a retrospective, nested, case-control study of children with SCD <18 years who had respiratory viral panels (RVPs) performed at Children's Healthcare of Atlanta from 2012 to 2019. We abstracted the medical records to describe the demographics, clinical features, and outcomes of children who tested positive for RSV (cases) versus children who tested negative (controls). We calculated the annual incidence of RSV and related hospitalization rates with 95% confidence intervals (CIs) and used multivariate logistic regression to evaluate associations. RESULTS: We identified 3676 RVP tests performed on 2636 patients over seven respiratory seasons resulting in 219/3676 (6.0%) RSV-positive tests among 160/2636 (6.1%) patients. The average annual incidence of laboratory-confirmed RSV infection among children with SCD was 34.3 (95% CI 18.7-49.8) and 3.8 (95% CI 0.5-7.0) cases per 1000 person-years for those <5 years and 5-18 years, respectively. The RSV-related hospitalization rate for children <5 years was 20.7 (95% CI 8.5-32.8) per 1000 person-years. RSV-positive cases were significantly younger than RSV-negative patients (3.8 years vs 7.6 years, P < .001). Of RSV-positive cases, 22 (13.8%) developed acute chest syndrome and nine (5.6%) required intensive care, which was not significantly different from RSV-negative children with SCD. CONCLUSION: RSV infections are common in children with SCD with higher burden in younger patients. RSV is associated with considerable morbidity, including higher rates of hospitalization compared to the general population.

Clinical outcomes following bone marrow transplantation in patients with sickle cell disease: A cohort study of US Medicaid enrollees.

OBJECTIVES: Bone marrow transplantation (BMT) is currently the only curative therapy available for patients with sickle cell disease (SCD), but clinical outcomes in routine care are not well understood. We describe the rates of vaso-occlusive crises (VOCs), transplant complications, and mortality in SCD patients after BMT. METHODS: A cohort study of SCD patients who underwent BMT was designed using US Medicaid claims data (2000-2013). RESULTS: A total of 204 SCD patients undergoing BMT were identified with a mean (SD) age of 10.6 (7.3) years, with 52.9% male and 67.6% African American. The overall VOC rate was 0.99 per person-year (95% CI: 0.91-1.07) over a median follow-up time of 2.1 years (IQR: 0.8-4.3 years). A total of 138 (67.6%) remained free of VOCs. The mortality rate was 1.7 (95% CI: 0.9-3.1) per 100 person-years, transplant-related complications occurred among 113 (55.4%) patients with an incidence rate of 38.2 (95% CI: 31.7-45.9) per 100 person-years, while 47 (23%) patients had GvHD with an incidence rate of 8.0 (95% CI: 6.0-10.7) per 100 person-years. CONCLUSION: Two thirds of the BMT recipients remained VOC-free over 2 years of follow-up, but transplant-related complications, including GvHD occurred with high frequency. This highlights a continuing unmet need for alternative curative interventions in SCD.

Influenza vaccine effectiveness and disease burden in children and adolescents with sickle cell disease: 2012-2017.

BACKGROUND: Data are limited on the burden of influenza and seasonal influenza vaccine effectiveness (VE) in children with sickle cell disease (SCD). METHODS: We used a prospectively collected clinical registry of SCD patients 6 months to 21 years of age to determine the influenza cases per 100 patient-years, vaccination rates, and a test-negative case-control study design to estimate influenza VE against medically attended laboratory-confirmed influenza infection. Influenza-positive cases were randomly matched to test-negative controls on age and influenza season in 1:1 ratio. We used adjusted logistic regression models to compare odds ratio (OR) of vaccination in cases to controls. We calculated VE as [100% × (1 - adjusted OR)] and computed 95% confidence intervals (CIs) around the estimate. RESULTS: There were 1037 children with SCD who were tested for influenza, 307 children (29.6%) had at least one influenza infection (338 infections, incidence rate 3.7 per 100 person-years; 95% CI, 3.4-4.1) and 56.2% of those tested received annual influenza vaccine. Overall VE pooled over five seasons was 22.3% (95% CI, -7.3% to 43.7%). Adjusted VE estimates ranged from 39.7% (95% CI, -70.1% to 78.6%) in 2015/2016 to -5.9% (95% CI, -88.4% to 40.4%) in the 2016/17 seasons. Influenza VE varied by age and was highest in children 1-5 years of age (66.6%; 95% CI, 30.3-84.0). Adjusted VE against acute chest syndrome during influenza infection was 39.4% (95% CI, -113.0 to 82.8%). CONCLUSIONS: Influenza VE in patients with SCD varies by season and age. Multicenter prospective studies are needed to better establish and monitor influenza VE among children with SCD.

Acute Chest Syndrome After Splenectomy in Children With Sickle Cell Disease.

BACKGROUND: Individuals with sickle cell disease (SCD) are at high risk of developing life-threatening complications, particularly acute chest syndrome (ACS) postoperatively. The perioperative factors associated with the development of ACS in children with SCD after splenectomy have not been clearly identified. MATERIALS AND METHODS: We retrospectively reviewed medical records of all children who underwent splenectomy at our institution between 1997 and 2017 with the goal of identifying perioperative factors associated with postoperative ACS. Categorical and noncategorical variables were compared using Fisher's exact test and Student's two-tailed t-test, respectively. RESULTS: Sixty-five patients with SCD underwent splenectomy at a median of 4.0 (interquartile range [IQR] 2.0-8.0) years of age. A laparoscopic approach was used for 64 (98.5%) patients. Fifty-six (86.2%) underwent laparoscopic total splenectomy, and eight (12.3%) underwent laparoscopic partial splenectomy, of which two were converted to open. One had an open partial splenectomy (1.5%). Of the 65 patients, 10 (15.4%) developed ACS with a mean time to diagnosis of 49.0 ± 34.5 h. Children who developed ACS had a higher postoperative median pain score of 6.8 (IQR 5.1-9.1) versus 2.7 (IQR 1.6-4.2), P < 0.001, higher median pain score area under the curve 111.5 (IQR 76.9-169.1) versus 47.3 (IQR 30.5-78.3), P = 0.01, and received more total morphine equivalents (median 1.4 [IQR 0.4-2.7] versus 0.5 [IQR 0.3-0.9] mg/kg, respectively; P = 0.003), compared with children who did not develop ACS. CONCLUSIONS: Significant postoperative pain may be an early sign of ACS that could be worsened by opioid use, supporting the investigation of nonopioid pain control options in this patient population.

Causes of hospitalization in sickle cell diseased children in western region of Saudi Arabia. A single center study.

OBJECTIVES: To highlight the causes of hospitalization among sickle cell diseased (SCD) children in Al-Madinah Al-Munawarah, Saudi Arabia. METHODS: A retrospective study conducted at the Maternity and Children's Hospital, Al-Madinah Al-Munawarah, Saudi Arabia. A data of 739 SCD children admitted to the hematology/oncology unit between October 2010 and September 2015 were collected. The collected data were analyzed using an independent t test and a Chi square test as appropriate. RESULTS: Approximately 49% of the studied children were presented by acute painful crisis. Acute chest syndrome was reported in 20.9%. Infection was the cause of admission in 17.5%, and acute anemia was reported in 8.1% of the studied patients. No significant difference of the reported clinical manifestations by patients' gender. Children aged <12 years showed significantly high frequency of acute chest syndrome (ACS) (26.5%), while acute painful crisis (66.4%) was significantly more frequent among children aged ≥12 years. CONCLUSION: This study revealed high rate of hospitalization of SCD children because of acute painful crisis, ACS, infection, and anemia. These admissions causes could potentially be continuously assessed to minimize the rate of hospitalization.

Low-risk factors for severe bacterial infection and acute chest syndrome in children with sickle cell disease.

INTRODUCTION: The rate of bacterial infections in children with sickle cell disease (SCD) has decreased in recent years, mainly due to penicillin prophylaxis and vaccination. OBJECTIVES: To determine the rate of severe bacterial infection (SBI) in a cohort of children with SCD and to describe low-risk factors for confirmed SBI (CSBI) and acute chest syndrome (ACS). METHODS: This 11-year retrospective cohort study included children with febrile SCD admitted to a reference hospital in Spain. A case-control study was performed comparing patients diagnosed with SBI to those without SBI, and subanalyses for groups with CSBI and ACS were carried out. RESULTS: A total of 316 febrile episodes were analyzed; 69 (21.8%) had confirmed or possible SBI. Thirteen of those had CSBI (4.1%), eight urinary tract infection, and five bacteremia/sepsis. Among the cases of possible SBI, the majority had ACS (54/56; 96.4%). Age >3 years, absence of central venous catheter, hemodynamic stability, and procalcitonin <0.6 ng/ml were low-risk factors for CSBI, whereas normal oxygen saturation and C-reactive protein <3 mg/dl were low-risk factors for ACS, with negative predictive values (NPV) of 98.3%, 97.4%, 96%, 97.2%, 87.5%, and 85.8%, respectively. CONCLUSION: In this cohort of children with SCD who were well vaccinated and received adequate prophylaxis, we found a low rate of bacteremia and CSBI. We described several low-risk factors for CSBI and ACS, all of them with a high NPV. These findings may help to develop a risk score to safely select the patients that could be managed with a more conservative approach.

Children with HbSß0 thalassemia have higher hemoglobin levels and lower incidence rate of acute chest syndrome compared to children with HbSS.

BACKGROUND: Based on the presumed clinical similarity between the two most severe sickle cell disease (SCD) genotypes, hemoglobin (Hb) Sß0 thalassemia and HbSS, randomized controlled trials (RCTs) have included both genotypes. Our group has demonstrated that healthcare providers inadequately distinguish the two diagnoses through clinical and laboratory parameters. PROCEDURE: In a retrospective cohort study utilizing data from the Silent Cerebral Infarct Transfusion trial (NCT00072761), we tested the hypothesis that children with genotypic diagnoses of HbSß0 thalassemia, when compared to HbSS, have significantly different rates of SCD comorbidities. Exclusion criteria included those with previous overt stroke or treatment with hydroxyurea or regular blood transfusion therapy. RESULTS: Among children with HbSß0 thalassemia (n = 22) and HbSS (n = 786), the mean hemoglobin was higher in children with HbSß0 thalassemia (9.2 g/dl) compared to HbSS (8.1 g/dl, P < 0.001). In children with HbSß0 thalassemia, when compared to HbSS, the incidence rate of acute chest syndrome (ACS) was 3.0 and 14.4 events per 100 patient-years (P = 0.028), and mean transcranial Doppler (TCD) velocities were 112.6 and 135.6 cm/sec, respectively (P = 0.026). The number of children with HbSß0 thalassemia and HbSS with conditional TCD velocities were zero (0%) and 26 (4.9%), respectively (P = 1.00), and the number with silent cerebral infarcts were five (27.8%) and 209 (30.8%), respectively (P = 0.78). CONCLUSIONS: We have provided preliminary evidence that clinically relevant differences occur in ACS rates and TCD velocities between children with HbSß0 thalassemia and HbSS. Future SCD RCTs should consider balanced allocation of these SCD genotypes, particularly when ACS and abnormal TCD velocities are primary outcome measures.

Acute chest syndrome among children hospitalized with vaso-occlusive crisis: A nationwide study in the United States.

PURPOSE: Acute chest syndrome (ACS) is a common complication among pediatric inpatients with sickle cell disease and vaso-occlusive crisis (VOC). However, little is known about the factors associated with ACS complication. The present study assessed the epidemiological features of children hospitalized with VOC and ascertained factors associated with ACS complication. METHODS: Hospital discharge records of patients with VOC aged <20 years were obtained for the years 2003, 2006, 2009, and 2012 from the Kids' Inpatient Database. Data were weighted to estimate the annual hospitalization rates with respect to gender and race/ethnicity in the United States. Multivariable logistic regression was conducted to ascertain factors associated with ACS complication after adjusting for patient and hospital characteristics. RESULTS: The total annual hospitalizations for VOC increased from 22,511 in 2003 to 24,292 in 2012. Multivariable logistic regression analysis showed that children aged 5-9 years had 2.59 times higher odds of ACS than children aged 15-19 years (95% confidence interval [CI], 2.32-2.88). Comorbidity of asthma (odds ratio [OR], 1.42; 95% CI, 1.31-1.54) and obstructive sleep apnea (OR, 1.70; 95% CI, 1.31-2.20) were associated with ACS development. ACS was also associated with male gender and the summer and fall seasons. CONCLUSION: We reported nationwide estimates of the annual hospitalization rate for childhood VOC in the United States and demonstrated the major risk factors associated with ACS complication. Vigilance is needed for ACS complications in high-risk VOC admissions.

Pulmonary function in children and adolescents with sickle cell disease: have we paid proper attention to this problem? / Função pulmonar em crianças e adolescentes com doença falciforme: temos dado atenção adequada a esse problema?

ABSTRACT Objective: To evaluate pulmonary function and functional capacity in children and adolescents with sickle cell disease. Methods: This was a cross-sectional study involving 70 children and adolescents (8-15 years of age) with sickle cell disease who underwent pulmonary function tests (spirometry) and functional capacity testing (six-minute walk test). The results of the pulmonary function tests were compared with variables related to the severity of sickle cell disease and history of asthma and of acute chest syndrome. Results: Of the 64 patients who underwent spirometry, 15 (23.4%) showed abnormal results: restrictive lung disease, in 8 (12.5%); and obstructive lung disease, in 7 (10.9%). Of the 69 patients who underwent the six-minute walk test, 18 (26.1%) showed abnormal results regarding the six-minute walk distance as a percentage of the predicted value for age, and there was a ≥ 3% decrease in SpO2 in 36 patients (52.2%). Abnormal pulmonary function was not significantly associated with any of the other variables studied, except for hypoxemia and restrictive lung disease. Conclusions: In this sample of children and adolescents with sickle cell disease, there was a significant prevalence of abnormal pulmonary function. The high prevalence of respiratory disorders suggests the need for a closer look at the lung function of this population, in childhood and thereafter.

RESUMO Objetivo: Avaliar a função pulmonar e a capacidade funcional em crianças e adolescentes com doença falciforme. Métodos: Estudo transversal com 70 crianças e adolescentes com doença falciforme (8-15 anos), submetidos a testes de função respiratória (espirometria) e de capacidade funcional (teste de caminhada de seis minutos). Os resultados da avaliação da função pulmonar foram comparados com variáveis relacionadas à gravidade da doença falciforme e à presença de história de asma e de síndrome torácica aguda. Resultados: Dos 64 pacientes submetidos à espirometria, 15 (23,4%) apresentaram resultados alterados: distúrbio ventilatório restritivo, em 8; (12,5%) e distúrbio respiratório obstrutivo, em 7 (10,9%). Dos 69 pacientes submetidos ao teste de caminhada de seis minutos, 18 (26,1%) apresentaram resultados alterados na distância em % do previsto para a idade, e houve uma queda ≥ 3% na SpO2 em 36 (52,2%) dos pacientes. Não houve associações significativas entre função pulmonar alterada e as outras variáveis analisadas, exceto para hipoxemia e distúrbio ventilatório restritivo. Conclusões: Observou-se uma significativa prevalência de alterações na função pulmonar nesta amostra de crianças e adolescentes com doença falciforme. A elevada prevalência de distúrbios ventilatórios sugere a necessidade de um olhar mais atento à função pulmonar desde a infância nessa população.

The Changing Epidemiology of Pediatric Hemoglobinopathy Patients in Northern Alberta, Canada.

BACKGROUND: Hemoglobinopathies are associated with significant morbidity and mortality. Accurate epidemiologic data reflecting the number of hemoglobinopathy patients are lacking in Canada. Immigration patterns are shifting such that regions where these diseases were rare are seeing a rapid population expansion, revealing a gap in the health care system and the need for a public health response. METHODS: To understand the epidemiology of pediatric hemoglobinopathy patients given the provincial population growth and immigration patterns, a retrospective chart review was conducted at the Stollery Children's Hospital from January 2004 to July 2014. RESULTS: A total of 88% of patients had sickle cell disease; 55% of patients were Canadian born and 63% of families originated from Africa. There was a 3.5-fold increase in patient numbers with acceleration in patient accrual over the study period and a delay in diagnosis in 70% of patients. There was a significant increase in the number of hospitalizations over the study period. Thirteen percent required at least 1 exchange transfusion, 16% received chronic transfusions, and 30% of patients developed at least 1 severe complication related to their diagnosis. CONCLUSIONS: It is imperative to demonstrate the growing hemoglobinopathy population and changing health care requirements to advocate for appropriate resources, educate health care providers, and increase awareness.

Vitamin D deficiency and acute vaso-occlusive complications in children with sickle cell disease.

BACKGROUND: Vitamin D is increasingly recognized for its roles in non-skeletal disorders. Patients with sickle cell disease (SCD) have a high prevalence of vitamin D deficiency but data are limited with respect to possible associations between low vitamin D and acute vaso-occlusive complications. We examined whether vitamin D deficiency is associated with acute pain and acute chest syndrome (ACS) in children with SCD. PROCEDURE: A cross-sectional study was conducted in 95 children with SCD who had serum 25-hydroxyvitamin D (25-OHD) measured during comprehensive care examinations. History of acute pain and ACS within two years of obtaining 25-OHD was collected. Associations between 25-OHD levels and acute vaso-occlusive events were analyzed by logistic regression. Odds ratios and 95% confidence intervals were calculated for the risk of pain and ACS associated with vitamin D deficiency (25-OHD <20 ng/ml). RESULTS: Subjects were 3-20 years old (median 10.6); 48 males, 47 females; 46 African, 49 Hispanic; 72 SS, 20 SC, 1 S/ß(0) Thalassemia, and 2 S/ß(+) Thalassemia. Median 25-OHD was 16 ng/ml. Fifty-six (59%) were vitamin D-deficient. Thirty-one (33%) and 29 (31%) had at least one episode of pain and ACS, respectively. Serum 25-OHD was significantly associated with pain (P = 0.0121) but not with ACS (P = 0.628). Of those with pain, 73% (23/31) were vitamin D-deficient while 26% (8/31) had 25-OHD ≥20 ng/ml (P = 0.04, OR = 2.7, 95%CI = 1.05-6.94). CONCLUSIONS: Our findings emphasize the high prevalence of vitamin D deficiency and its potential association with acute pain in SCD. Correcting low vitamin D may offer a simple, low-cost intervention to help reduce acute vaso-occlusive complications.

Acute chest syndrome after laparoscopic splenectomy in children with sickle cell disease: operative time dependent?

BACKGROUND: Laparoscopic splenectomy remains a technically demanding procedure. On patients with sickle cell disease (SCD), a post operative acute chest syndrome (ACS) can occur. The aim of the study was to look for predictive factors of post operative ACS. PATIENTS AND METHOD: It's a retrospective study on patients with SCD, who underwent a laparoscopic splenectomy in Robert Debré hospital, Paris, France, between March 2008 and December 2013. Diagnosis of ACS was done if the patient developed hypoxemia associated with fever above 38.5 °C and an infiltrate on chest x ray during the post operative course. Pre-, post- and operative factors were studied. Descriptive statistics were compared using the Mann-Whitney test or the exact Fisher test. A p inferior to 0.05 was considered as significant. RESULTS: 52 patients with SCD underwent a laparoscopic splenectomy. Twelve patients presented a post operative ACS (23%) (mean age at surgery 4 years old) while forty did not (mean age 5.25 years old). Neither previous episode of ACS nor any factors reflecting SCD severity were significant. The shorter the operative time was, the greater the risk of developing an ACS (p < 0.05). CONCLUSION: ACS is an important complication following laparoscopic splenectomy in patients with SCD. The immediate post operative management, in the absence of predictive factors for ACS, should be carefully followed in a high dependency unit at least for 48 h for all patients.

Practice patterns of stroke screening and hydroxyurea use in children with sickle cell disease: a survey of health care providers.

Incidence of stroke in sickle cell disease (SCD) has declined with the use of transcranial Doppler ultrasound and chronic transfusion therapy. There is little information regarding their use in genotypes other than HbSS and HbSß. Silent cerebral infarcts (SCIs) have been identified by magnetic resonance imaging (MRI) in SCD patients and it is believed that these may increase the risk of overt stroke. No evidence-based guidelines exist regarding MRI screening for SCIs. Hydroxyurea is a standard therapy in patients with history of acute chest syndrome and severe, recurrent, SCD-associated pain episodes, but has not been established for use with other sickle-associated morbidities. A total of 102 institutions received a survey (with 62 responses) to assess the use of transcranial Doppler ultrasound for stroke screening, use of screening MRI for SCIs, and institutional patterns for prescribing hydroxyurea. Nineteen percent of institutions screen genotypes other than HbSS and HbSß, and 24% use MRI to screen for SCIs. Twenty-six percent of institutions prescribed hydroxyurea in patient found to have SCIs. Results indicate significant variation in stroke screening and hydroxyurea use often correlating with clinic size, number of physician providers, and geographic location. There are currently no evidence-based guidelines to support many of these practices.

Pulmonary function abnormalities and asthma are prevalent in children with sickle cell disease and are associated with acute chest syndrome.

Pulmonary diseases form major sources of morbidity and mortality in children with sickle cell disease (SCD). The objective of the study was to determine the prevalence of lung function abnormalities and asthma and their association with acute chest syndrome (ACS) in children with SCD. This was a cross-sectional retrospective study of 127 children with SCD; we collected information regarding ACS and asthma and pulmonary function test (PFT) data. Based on PFT results, the patients were assigned to one pattern of lung function [normal, obstructive lung disease (OLD), restrictive lung disease (RLD)]. Statistical analyses included Pearson correlation, prevalence odds ratio (POR), cross-tabulation, and multiple binary logistic regression. OLD was noted in 35% and RLD in 23% of the patients, with the remainder exhibiting a normal PFT pattern. Forty-six percent of patients had asthma, 64% of whom had a history of ACS. OLD (r = .244, P = .008, POR = 2.8) and asthma (r = .395, P < .001, POR = 5.4) were significantly associated with a history of ACS. There was a negative correlation between having normal PFT data and a history of ACS (r = -.289, P = .002, POR = .3). Asthma and pulmonary function abnormalities are prevalent in children with SCD, with OLD being more common than RLD. There is an association between asthma, OLD, and ACS, however causality cannot be proven due to the study design. We stress the importance of actively investigating for a clinical diagnosis of asthma in all patients with SCD and suggest that PFT data may help detect patients at lower risk for ACS.

Mortality, asthma, smoking and acute chest syndrome in young adults with sickle cell disease.

PURPOSE: Sickle cell disease (SCD) patients with asthma have an increased risk of death. Acute chest syndrome (ACS) is a major cause of mortality in patients with SCD, and ACS may be more common in SCD patients who smoke. The purpose of this study was to test the hypothesis that mortality in young adults with SCD would be greater than that of controls during a 10-year period and to determine whether asthma, reduced lung function, ACS episodes, and/or smoking predicted mortality during the follow-up period. METHODS: The outcomes during a 10-year period were ascertained of SCD patients and race-matched controls who had taken part in a pulmonary function study when they were between age 19 and 27 years. Smoking and asthma status and whether they had had ACS episodes were determined, and lung function was measured at the initial assessment. RESULTS: Seventy-five subjects with SCD were followed for 683 patient years. There were 11 deaths with a mortality rate of 1.6 deaths per 100 patient years, which was higher than that of the controls; one death in 47 controls was observed for 469 patient years with a mortality rate of 0.2 per 100 patient years (p = 0.03). There were no significant associations of body mass index, recurrent episodes of acute chest, steady state haemoglobin, or gender with mortality. Adjusting for baseline lung function in SCD patients, "current" asthma [hazard ratio (HR) 11.2; 95 % confidence interval (CI) 2.5-50.6; p = 0.002] and smoking [HR 2.7; (95 % CI 1.3-5.5); p = 0.006] were significantly associated with mortality during the 10-year period. CONCLUSIONS: Our results indicate that young adults with SCD should be discouraged from smoking and their asthma aggressively treated.

Hydroxyurea treatment of children with hemoglobin SC disease.

The efficacy of hydroxyurea in hemoglobin SC (HbSC) patients is not well documented. We describe the long-term response to hydroxyurea in children with clinically severe HbSC. In 15 patients, hydroxyurea resulted in a significant increase in mean corpuscular volume (MCV) and fetal hemoglobin (HbF) and a significant decrease in episodes of acute chest syndrome and hospitalization for pain; there was no effect on hemoglobin level. The most significant side effect was thrombocytopenia, which led to discontinuation of treatment in one patient. This study suggests that hydroxyurea has efficacy and is safe for long-term therapy in patients with HbSC.