Asthma is associated with increased mortality in individuals with sickle cell anemia.

An analysis of a prospective cohort of individuals with sickle cell anemia (SCA), enrolled from birth through adulthood, was conducted to determine if asthma is a risk factor for death in SCA. All-cause mortality was determined for participants after adjusting for known risk factors for death in SCA. The study included 1,963 individuals who were followed for 18,495 patient-years. After controlling for established risk factors, individuals with SCA and asthma had a more than two-fold higher risk of mortality (hazard ratio 2.36, 95% CI 1.21 to 4.62, p=0.01). To summarize, asthma is a risk factor for death in SCA.

Inadequate community knowledge about sickle cell disease among African-American women.

BACKGROUND: Federal legislation was passed in 1972 initiating genetic screening and community education about sickle cell disease (SCD). Few assessments have examined the impact of these programs. The aim of this study is to assess existing knowledge about SCD among African-American women in St. Louis, MO. METHODS: We conducted a cross-sectional telephone survey of African-American women, 18-30 years of age. Participants were recruited through random-digit dialing in six ZIP codes with greater than 75% African-American residents. The survey contained questions exploring four content domains about SCD: general knowledge, genetics, management and educational resources. RESULTS: A total of 264 women were contacted; 30% were unable to complete the survey and participate further because they were unaware of SCD. One-hundred-sixty-two women met eligibility criteria, agreed to be surveyed and were included in the study. Ninety-one percent of the participants believed that SCD was a hereditary blood disorder, but only 9.3% understood the inheritance pattern. Eleven percent of the women were unaware of their sickle cell trait status. Most women recognized pain (94%), infections (80%) and strokes (40%) as complications of SCD. CONCLUSION: New strategies are needed to enhance awareness of SCD among African-American women of childbearing age.

Asthma and acute chest in sickle-cell disease.

Our objective was to determine if physician-diagnosed asthma increases the risk of acute chest syndrome (ACS) in children with sickle-cell disease (SCD) hospitalized for pain. Our study design was a retrospective case-control study of all SCD patients, aged 2-21 years, hospitalized for pain during the interval 1999-2000. Medical records of first admissions during the interval were reviewed to determine the presence of ACS during the admission. Cases were defined as patients with ACS, and controls were patients without ACS. Independently, medical records of admissions prior to the study interval were reviewed for evidence of physician-diagnosed asthma. Sixty-three cases with ACS and 76 controls without ACS were identified. No significant differences in gender, age, and hemoglobin phenotype were found. Patients with physician-diagnosed asthma were 4.0 times (95% CI, 1.7, 9.5) more likely to develop ACS during the admission than patients without asthma. Individuals with physician-diagnosed asthma had a longer hospitalization for ACS, i.e., 5.6 days vs. 2.6 days, respectively (P = 0.01). In conclusion, our preliminary data suggest that asthma in children with SCD admitted to the hospital for pain may be a risk factor for ACS and may increase the duration of hospitalization when compared to children with SCD and without asthma.

Lower airway obstruction is associated with increased morbidity in children with sickle cell disease.

RATIONALE: The association between pulmonary function and morbidity in children with sickle cell disease (SCD) has not been previously evaluated. Our objective was to study the relationship between abnormalities in pulmonary function and morbidity as represented by the rate of hospitalizations for pain or acute chest syndrome (ACS) in children with SCD. METHODS: Results of pulmonary function tests obtained for clinical indications in children ages 6-18 years were classified as lower airway obstruction (forced expiratory volume in 1 sec/forced volume capacity <95% confidence interval adjusted for age, gender, race, and height), restriction (total lung capacity <80% predicted adjusted for gender, age, race, and height), and normal lung function. Incidence rates of pain or ACS were compared between children with lower airway obstruction or restriction and children with normal lung function. RESULTS: A total of 102 children, mean age at evaluation 12.0 years with follow-up of 3.8 years, were included. Children with lower airway obstruction had twice the rate of morbidity compared to children with normal lung function (2.5 vs. 1.2 hospitalizations for pain or ACS per patient-year, P = 0.003) (Risk ratio: 2.0; 95% CI: 1.3-3.3). Children with restriction did not have different rates of future morbidity compared to children with normal lung function (1.4 vs. 1.2 hospitalizations for pain or ACS per patient-year, P = 0.68) (Rate ratio: 1.1; 95% CI: 0.6-2.1). CONCLUSIONS: We conclude that children with SCD who have lower airway obstruction should have increased surveillance for future morbidity.

Methacholine challenge in children with sickle cell disease: a case series.

Lung disease is a major cause of morbidity in children with sickle cell disease (SCD). Asthma in children with SCD is associated with a twice greater rate of pain and acute chest syndrome (ACS) episodes when compared to children with SCD but without asthma. Provocation challenges with methacholine are used to diagnose asthma when spirometry is normal, bronchodilator reactivity is absent, or the clinical picture is ambiguous. There have been only limited descriptions of use of methacholine challenge in individuals with SCD. We conducted a retrospective cohort study of 21 children with SCD and recurrent respiratory tract symptoms who were challenged with methacholine to determine if airway hyper responsiveness (AHR) was present. Fourteen (67%) of the children had a positive challenge. Of the 14 patients, four were given a new diagnosis of asthma based on the presence of chronic chest symptoms and the newly determined AHR and started on inhaled corticosteroids (ICS). In each positive challenge, forced expiratory volume in one second (FEV(1)) was reversed to at least 90% of baseline 15 min after bronchodilator treatment. Oxygen saturation decreased in 93% of those with a positive challenge, but returned to baseline values 15 min after bronchodilator treatment. No patient developed a pain or ACS episode within at least 1 month after the challenge. Evaluation of AHR with methacholine challenge in patients with SCD appears to be well tolerated and may elucidate a cause of SCD morbidity.

Major gene effect and additive familial pattern of inheritance of asthma exist among families of probands with sickle cell anemia and asthma.

In the United States, sickle cell anemia (SCA) affects approximately 1 in 400 African-American newborns. Acute episodes of pain and acute chest syndrome (ACS) are the two leading causes of hospitalization. A relationship between the diagnosis of asthma and the incidence of pain and ACS has been established. We tested the hypothesis that a familial pattern of inheritance of asthma exists among first degree relatives of probands with SCA and asthma. Segregation analysis was performed in 104 families ascertained through affected probands. Of these, 19.7% (41/208) of the parents and 31.8% (28/88) of siblings of affected probands reported having been told by a doctor he or she had asthma at any age. Modes of inheritance were tested, using the Pedigree Analysis Package parameterized for the discrete trait of asthma affection status. A major effect was present and significant. Further tests were performed to determine whether transmission probabilities of the major effect followed Mendelian expectations. The additive mode of inheritance was the most parsimonious, while the residual heritability was found negligible. Our results support the hypothesis that a familial pattern of inheritance of asthma exists among first degree relatives of probands with SCA and asthma, suggesting that asthma is a co-morbid condition with SCA rather than a lung disease phenotype mimicking asthma.

Asthma is associated with acute chest syndrome and pain in children with sickle cell anemia.

Pain and acute chest syndrome (ACS) episodes are 2 of the most common causes of hospitalization in children with sickle cell anemia (SCA). However, very few potentially modifiable risk factors for either condition have been identified. In this prospective infant cohort study, we tested the hypothesis that asthma is associated with an increased incidence rate of pain and ACS episodes. An infant cohort was composed of 291 African American children with hemoglobin SS enrolled in the Cooperative Study for Sickle Cell Disease before age 6 months and followed beyond age 5 years. Asthma was defined by a physician diagnosis, an acute asthma event, or use of prescription asthma medications. The incidence rates of ACS and painful episodes were compared for children with and without asthma. A clinical diagnosis of asthma was made in 17% of the cohort. Asthma was associated with more frequent ACS episodes (0.39 vs 0.20 events per patient year, P < .001) and painful episodes (1.39 vs 0.47 events per patient year, P < .001). In conclusion, in children with SCA, asthma is associated with an increased incidence of sickle cell disease-related morbidity, including ACS and painful episodes.

Mailing of a sickle cell disease educational packet increases blood donors within an African American community.

BACKGROUND: Low blood donor rates among African American persons are recognized; however, few strategies exist to increase these numbers. STUDY DESIGN AND METHODS: A 1-year, prospective, ecologic study performed before and after an educational intervention designed to test the hypothesis that increased education about the importance of blood donation for children with sickle cell disease (SCD) would result in an increase in total blood donors among African American persons. RESULTS: Approximately 5000 videos were mailed to 50 percent of the households in a zip code where 98 percent of the residents are African American. In the first 6-month interval after mailing the video packet, there was a 75 percent (217 vs. 124; p = 0.05) increase in the total number of presenting donors and a 64 percent (126 vs. 77; p = 0.02) increase in the total number of first-time donors from the same 6-month period in the previous year. During the second 6-month interval, the total number of first-time donors declined. No significant increase in donor activity was noted during the two 6-month periods after the intervention in the surrounding zip codes. CONCLUSION: A mass mailing directed toward educating African American persons about the importance of blood donation for children with SCD may increase the number of total African American donors.