Clinical response of patients with sickle cell anemia to cromolyn sodium nasal spray

Sickle cell anemia is the most common heritable hematological disease affecting humans. Although hydroxyurea is the most commonly used antisickling agent, several previous studies suggest that cromolyn sodium also prevents sickling when administered acutely. However, no previous studies have evaluated the safety or efficacy of prolonged administration of cromolyn to patients with sickle cell anemia. The purpose of this study, therefore, was to test the hypothesis that prolonged administration of cromolyn alone or in combination with hydroxyurea would decrease the incidence of pain crises and/or alter the chronic pain seen in patients with this disease. In this crossover, single-blind, in vivo and in vitro study, 17 patients with sickle cell disease were studied. Each patient had to fill out a standard pain chart. Every 3 months the patients' medications changed in the following manner: The first 3 months the patients used cromolyn sodium nasal spray; the second 3 months they received placebo nasal spray; the third 3 months they received cromolyn sodium nasal spray and hydroxyurea capsule; and the last 3 months they received hydroxyurea capsule and placebo nasal spray. The least pain was felt with the mixture of hydroxyurea capsule and cromolyn sodium nasal inhaler. Furthermore, with the other combinations of medications, there were no significant statistical changes in the number of sickled red blood cells. Every combination used in this survey had positive effects on decreasing the pain. cromolyn sodium nasal spray is significantly efficient in decreasing sickle cell crisis as well as pain intensity in patients with sickle cell anemia.     

Sustained long-term hematologic efficacy of hydroxyurea at maximum tolerated dose in children with sickle cell disease

Hydroxyurea improves hematologic parameters for children with sickle cell disease (SCD), but its long-term efficacy at maximum tolerated dose (MTD) has not been determined. Between 1995 and 2002, hydroxyurea therapy was initiated for 122 pediatric patients with SCD including 106 with homozygous sickle cell anemia (HbSS), 7 with sickle hemoglobin C (HbSC), 7 with sickle/beta-thalassemia (HbS/ beta-thalassemia [6 HbS/beta0, 1 HbS/beta+]), and 2 with sickle hemoglobin OArab (HbS/OArab). Median age at initiation of therapy was 11.1 years. Hydroxyurea was escalated to MTD, with an average dose of 25.4 +/- 5.4 mg/kg per day; the average duration of hydroxyurea therapy has been 45 +/- 24 months (range, 6-101 months). Hydroxyurea was discontinued for 15 (12%) children with poor compliance. Mild transient neutropenia occurred, but no hepatic or renal toxicity was noted. Hydroxyurea therapy led to significant increases in hemoglobin level, mean corpuscular volume, and fetal hemoglobin (HbF) level, whereas significant decreases occurred in reticulocyte, white blood cell, and platelet counts and serum bilirubin levels. Children with variant SCD genotypes also had hematologic responses to hydroxyurea. HbF induction has been sustained for up to 8 years without adverse effects on growth or increased numbers of acquired DNA mutations. Long-term hydroxyurea therapy at MTD is well tolerated by pediatric patients with SCD and has sustained hematologic efficacy with apparent long-term safety.     

Biological action of nitric oxide donor compounds on platelets from patients with sickle cell disease

Several lines of evidence point to the potential role of nitric oxide (NO) in the pathophysiology, as well as in the therapy, of sickle cell disease (SCD). In this study, we compared the effects of NO on platelets from normal individuals and from patients with SCD. Three NO donors were used to deliver NO to platelets: sodium 2-(N, N-diethylamino)-diazenolate-2-oxide (DEANO), S-nitrosocysteine (CysNO) and sodium trioxdintrate (OXINO or Angeli's salt). ADP-induced platelet aggregation, CD62P expression, PAC-1 binding and calcium elevation were evaluated in paired studies of normal and SCD subjects. DEANO significantly reduced aggregation in SCD platelets compared with normal platelets. DEANO similarly reduced the extent of CD62P expression in SCD platelets. All NO donors reduced PAC-1 binding, but there were no significant differences between platelets from normal or SCD subjects. Calcium elevation, as induced by ADP, was not altered by the presence of NO donors. However, when platelets were stimulated with thrombin, there was an increased initial response of SCD platelets compared with normal platelets. Taken together, these data suggest that the mode of NO delivery to platelets may produce various physiological responses and the optimization of NO delivery may contribute to reducing platelet aggregation in sickle cell disease.     

The Effect of Disodium Cromoglycate Against Bronchial Hyperresponsiveness in Asthmatic Children

A long-term study of the effect of cromolyn sodium against bronchial hyperresponsiveness in asthmatic children is described. Cromolyn sodium powder (20 mg), as the capsule formulation, was inhaled by Spinhaler® Turbohaler, tid, for three years. Histamine inhalation tests were performed every 6 months according to the standardized methods of the Japanese Allergy Congress. No other antiasthmatic therapy was given throughout the study except during an acute attack. Bronchial hyperresponsiveness decreased, and clinical symptoms improved throughout the trials. It is suggested that long-term use of cromolyn sodium reduces bronchial hyperresponsiveness concomitant with improved symptomatology in asthmatic children.     

Silent cerebral infarcts occur despite regular blood transfusion therapy after first strokes in children with sickle cell disease

Children with sickle cell disease (SCD) and strokes receive blood transfusion therapy for secondary stroke prevention; despite this, approximately 20% experience second overt strokes. Given this rate of second overt strokes and the clinical significance of silent cerebral infarcts, we tested the hypothesis that silent cerebral infarcts occur among children with SCD being transfused for secondary stroke prevention. A prospective cohort enrolled children with SCD and overt strokes at 7 academic centers. Magnetic resonance imaging and magnetic resonance angiography of the brain were scheduled approximately every 1 to 2 years; studies were reviewed by a panel of neuroradiologists. Eligibility criteria included regularly scheduled blood transfusion therapy. Forty children were included; mean pretransfusion hemoglobin S concentration was 29%. Progressive cerebral infarcts occurred in 45% (18 of 40 children) while receiving chronic blood transfusion therapy; 7 had second overt strokes and 11 had new silent cerebral infarcts. Worsening cerebral vasculopathy was associated with new cerebral infarction (overt or silent; relative risk = 12.7; 95% confidence interval, 2.65-60.5, P = .001). Children with SCD and overt strokes receiving regular blood transfusion therapy experience silent cerebral infarcts at a higher rate than previously recognized. Additional therapies are needed for secondary stroke prevention in children with SCD.     

Haemoglobin F modulation in childhood sickle cell disease

While supportive care remains the best option for most well children with sickle cell disease (SCD), increasing awareness of early signs of chronic organ damage in childhood has focused attention on therapy which modulates the natural history of the disease. Since cure by stem cell transplantation is only feasible for a minority and gene therapy remains developmental, pharmacological modification by Haemoglobin F (HbF)-inducers, is the most widely used approach in SCD. Currently, the only HbF modulator with a clear place in the management of childhood SCD is hydroxycarbamide for which the main indications are frequent painful crises and recurrent acute chest syndrome. In the majority of SCD children treated with hydroxycarbamide there is clear evidence of clinical benefit and the drug is well tolerated. The main disadvantages are the need for frequent monitoring and uncertainity about long-term risks of carcinogenicity and impaired fertility, although these risks appear to be very low. The role of hydroxycarbamide in sickle-associated central nervous system disease remains to be established. Decitabine and butyrate derivatives show some promise although robust data in children with SCD are lacking. A number of other drugs are currently under investigation for their effects on HbF production including thalidomide and lenolidamide.     

Should young children with sickle cell disease and an available human leukocyte antigen identical sibling donor be offered hematopoietic cell transplantation?

Availability of an HLA-identical sibling donor raises the question, “should young children with SCD, and an available HLA identical sibling donor be considered for hematopoietic cell transplantation (HCT) even before they manifest severe clinical presentations of sickle cell disease (SCD)?” The overall survival (OS) and event free survival (EFS) following HCT from an HLA identical sibling is excellent in young children, and worsen with increasing age at HCT. SCD related complications, organ dysfunction, quality of life, and risk for premature mortality all worsen with age. The ethical principles of non-maleficence, beneficence, autonomy and justice all support the consideration of this life, quality of life, and organ saving therapy at a young age.     

Malignancy in patients with sickle cell disease

Malignancy in patients with sickle cell disease (SCD) has been previously reported, but the types of cancer and its incidence remain undefined. With the advent of hydroxyurea therapy, there is concern about increasing the cancer risk for patients with SCD. The International Association of Sickle Cell Nurses and Physician Assistants identified 52 cases of cancer (49 patients) among 16,613 patients with SCD followed at 52 institutions. The median age at malignancy diagnosis was 34 years (range, 14 months-62 years). Twenty-one cases (40%) occurred in pediatric patients, primarily leukemia (n = 7) or Wilms' tumor (n = 5), with 15 children surviving. Most adults had solid tumors, especially carcinomas, and only nine were known to be alive. Three patients received hydroxyurea before the diagnosis of malignancy. These data provide essential baseline information for the accurate interpretation of future reports of malignancy in patients with SCD, especially those receiving hydroxyurea therapy.     

Paediatric haematologists’ attitudes regarding haematopoietic cell transplantation as treatment for sickle cell disease

Beginning early in childhood, patients with sickle cell disease [SCD; a group of genetic haemoglobin disorders characterized by the sickle or HbS mutation (HBB E7V)] are at risk of life-threatening and debilitating health events. Despite the high morbidity and mortality of this disease, haematopoietic cell transplantation (HCT), a curative therapy for SCD, remains underutilized. A variety of factors, including the limited availability of suitable donors, play a role in this trend, but do not fully explain the low frequency with which this therapy is employed. The objective of this study was to identify paediatric haematologists’ attitudes about HCT as a treatment option for SCD, and to describe the impact of these attitudes on their practices of discussing HCT with families of children affected by this disease. A nationwide survey of paediatric haematologists in the United States was conducted between February and May 2016. Two hundred and eighty-seven surveys were included in the final analysis (response rate 20%). On average, respondents reported informing 42% of families about HCT as a treatment option (N = 248, 95% confidence interval: 38–46). Clinician attitudes about the cost and safety of HCT were associated with practices of discussing this therapy with families. These findings suggest that clinician attitudes and referral practices may play a role in the underutilization of this therapy in the SCD population.     

Physical fitness indices and anthropometrics profiles in schoolchildren with sickle cell trait/disease

The current studies aimed at determining physical fitness indices and anthropometrics profiles of school children with sickle cell trait (SCT) and sickle cell disease (SCD). Male school children (150) comprising 3 Groups participated in the studies. Group 1 has 50 normal healthy controls, while Groups 2 and 3 each has 50 children who were suffering from SCT and SCD, respectively. Anthropometrics measurement and parameters of physical fitness were assessed in all subjects. All children were also subjected to a 5-min running exercise test on a flat motorized treadmill at speed corresponding to 5 km/hr. Throughout the test, heart rate was monitored and recorded during exercise and for 10-min during recovery. Blood lactate was measured before and 5 min following the completion of test. The mean values of lean body mass and height were lower in the SCD children (P < 0.05) compared with the healthy subjects and SCT individuals. Children with SCD exhibited a higher mean value (P < 0.05) for percent body fat and fat mass than the normal healthy subjects and SCT individuals. Although all groups tolerated well the treadmill exercise protocol, the SCD group exhibited higher (P < 0.05) mean values of heart rate during exercise than those observed in the SCT and normal control children. In addition, SCD children showed higher serum lactate values before and after treadmill exercise compared to the other groups. Children with SCD exhibit high level of adiposity; low level of fitness and their exercise performance appears to be physiologically more stressful as indicated by heart rate and blood lactate concentration responses.     

Plasma glial fibrillary acidic protein levels in a child with sickle cell disease and stroke

A 12-year-old boy with HbSS sickle cell disease (SCD) was admitted with an acute febrile illness and developed overt stroke 3 days later. Plasma glial fibrillary acidic protein levels were elevated, as compared to pediatric controls, 32 h prior to the clinical diagnosis of stroke, peaked immediately prior to the exchange transfusion, and remained elevated 1 year later despite chronic transfusion therapy. Stroke in SCD can occur in the setting of acute illness, and a biomarker that could predict the onset and triage ill children to therapeutic intervention more quickly would be useful.     

Steroid treatment in children with sickle-cell disease

Given the controversy concerning the effects of steroids in patients with sickle cell disease (SCD), we evaluated the tolerability of long-term steroid treatment in 16 children with SCD and autoimmune and/or systemic diseases. The steroid treatment was poorly tolerated.     

Diastolic dysfunction and pulmonary hypertension in sickle cell anemia: is there a role for L-carnitine treatment?

Clinical manifestations of cardiovascular abnormalities in patients with sickle cell (SC) anemia are well documented. Many variables were assessed in our study before and after administration of L-carnitine to randomly selected 37 SC disease (SCD) children for a period of 6 months. Variables such as weight, height, serum ferritin levels, units of blood transfused and the number of veno-occlusive crises all showed significant improvement after the 6 months of therapy with L-carnitine. Our study also showed that cardiac diastolic function and pulmonary hypertension are common in pediatric SCD patients. These two disorders showed some improvement after L-carnitine administration. Therefore, L-carnitine deserves a rigorous large-scale randomized clinical trial to evaluate its potential benefits as treatment for SCD patients with cardiac complications.     

A Double-Blind Comparative Study of Pelletized Cromolyn versus Cromolyn Blend in the Treatment of Asthma

In a randomized, double-blind, group comparative study, 100 asthmatic patients known to be responsive to cromolyn sodium were treated either with pelletized cromolyn (cromolyn sodium, 20 mg) or with cromolyn blend, Intalr` (cromolyn sodium, 20 mg + lactose, 20 mg). There was no statistically significant difference between the two treatment groups for asthma severity, breathlessness on exertion, cough, the number of inhalations needed to obtain the dose from the capsule, and morning peak flow. No local or systemic side effects were encountered during the 6-month duration of the study. It is concluded that pelletized cromolyn offers most of the advantages of cromolyn therapy without the need for the patients to inhale lactose at the same time. Also, pelletized cromolyn has a distinct therapeutic advantage for use in lactose-intolerant patients.     

A double-blind comparative study of pelletized cromolyn versus cromolyn blend in the treatment of asthma

In a randomized, double-blind, group comparative study, 100 asthmatic patients known to be responsive to cromolyn sodium were treated either with pelletized cromolyn (cromolyn sodium, 20 mg) or with cromolyn blend, Intal (cromolyn sodium, 20 mg + lactose, 20 mg). There was no statistically significant difference between the two treatment groups for asthma severity, breathlessness on exertion, cough, the number of inhalations needed to obtain the dose from the capsule, and morning peak flow. No local or systemic side effects were encountered during the 6-month duration of the study. It is concluded that pelletized cromolyn offers most of the advantages of cromolyn therapy without the need for the patients to inhale lactose at the same time. Also, pelletized cromolyn has a distinct therapeutic advantage for use in lactose-in-tolerant patients.     

A potent oral P-selectin blocking agent improves microcirculatory blood flow and a marker of endothelial cell injury in patients with sickle cell disease

Abnormal blood flow accounts for most of the clinical morbidity of sickle cell disease (SCD) [1,2]. Most notably, occlusion of flow in the microvasculature causes the acute pain crises [3] that are the commonest cause for patients with SCD to seek medical attention [4] and major determinants of their quality of life [5]. Based on evidence that endothelial P-selectin is central to the abnormal blood flow in SCD we provide results from four of our studies that are germane to microvascular blood flow in SCD. A proof-of-principle study established that doses of heparin lower than what are used for anticoagulation but sufficient to block P-selectin improved microvascular blood flow inpatients with SCD. An in vitro study showed that Pentosan Polysulfate Sodium (PPS) had greater P-selectin blocking activity than heparin. A Phase I clinical study demonstrated that a single oral dose of PPS increased microvascular blood flow in patients with SCD. A Phase II clinical study that was not completed documented that daily oral doses of PPS administered for 8 weeks lowered plasma levels of sVCAM-1 and tended to improve microvascular blood flow in patients with SCD. These data support the concept that P-selectin on the microvascular endothelium is critical to both acute vascular occlusion and chronically impaired microvascular blood flow in SCD. They also demonstrate that oral PPS is beneficial to microvascular sickle cell blood flow and has potential as an efficacious agent for long-term prophylactic therapy of SCD.     

Outcome of children with sickle cell disease admitted to intensive care – a single institution experience

We retrospectively audited children with sickle cell disease (SCD) admitted to paediatric intensive care (PICU) at King’s College Hospital between January 2000 and December 2008. Forty‐six children with SCD were admitted, on 49 separate occasions. Ages ranged from 4 months to 15 years (median 7·6 years). Three children died in PICU, however two presented to hospital in cardiorespiratory arrest; overall mortality was 6%. The most common reason for admission was acute chest syndrome (43%). 88% of admissions required blood transfusion, of which 74% had exchange blood transfusions. The mortality among children with SCD admitted to PICU is low.     

Modulation of erythrocyte arginase activity in sickle cell disease patients during hydroxyurea therapy

An elevated erythrocyte arginase activity with a corresponding decrease in nitric oxide (NO) level has been implicated in the pathophysiology of sickle cell disease (SCD). Recent studies have shown that hydroxyurea (HU) increases the production of NO, which increases the soluble guanylate cyclase activity and fetal haemoglobin (HbF) synthesis. To study the effects of HU on the arginase and nitric oxide synthase (NOS) activities in SCD patients, we compared levels of arginase activity and NO metabolites in red blood cells and plasma, respectively, from 23 patients with SCD (HbSS) receiving HU therapy, with those of 12 SCD patients not receiving HU treatment. Patients on HU therapy showed significantly lower arginase activity than that of HbSS patients not on HU therapy (1.36+/-0.2 U/10(8) cells vs. 3.31+/-0.29 U/10(8) cells). NOS activity was higher in patients on HU therapy than in untreated patients (0.72+/-0.4 nmol/ml/min vs. 0.35+/-0.15 nmol/ml/min, P<0.05). Among the HU-treated patients, the decreased level of arginase activity correlated (r=0.71) with HbF level as well as the mean corpuscular haemoglobin content. These data suggest that one of the beneficial effects of HU in vivo may involve the regulation of arginase activity and a concomitant induction of NOS activity, which may lead to an increased production of NO. The outcome of this study may lead to the development of improved NO-based treatments for SCD.     

Evaluation of parental preference for the treatment of asthmatic children aged 6 to 11 years with oral montelukast or inhaled cromolyn: a randomized, open-label, crossover study.

The objective of this study was to evaluate parental preference for the treatment of asthmatic children with oral montelukast sodium or inhaled cromolyn sodium. Additionally, we wanted to compare the two drugs in terms of patient preference for treatment, patient and parent satisfaction with treatment, frequency of inhaled albuterol use, adherence to treatment, and safety. This was a 12-week randomized, open-label, crossover study conducted in 42 primary care and asthma/allergy specialty centers in the United States. Three hundred thirty-three asthmatic patients, ages 6 to 11 years, who had a forced expiratory volume in 1 second (FEV1) of 60%-85% (inclusive) of predicted value with > or = 12% reversibility after administration of an inhaled beta-agonist and who used albuterol on at least 7 of the last 14 days of the run-in period. After a 2- to 3-week run-in period, patients were randomized either to 4 weeks of montelukast (5-mg chewable tablet once daily) followed by a 2-week washout period, then 4 weeks of cromolyn (two puffs 4 times daily from a metered-dose inhaler) or to the reverse sequence. More parents preferred montelukast (87%) than cromolyn (12%; p < 0.001). More patients preferred montelukast (82%) than cromolyn (17%; p < 0.001). Daily albuterol use (puffs/day) was reduced by 38% during montelukast therapy vs. 23% during cromolyn therapy. Seventy-eight percent of patients reported being highly adherent to montelukast therapy compared with 42% to cromolyn therapy (p < 0.001). Fewer patients receiving montelukast discontinued because of asthma exacerbation (1.0% vs. 5.0%, respectively), and fewer patients reported worsening asthma while receiving montelukast (3.5% vs. 7.5%, p = 0.036). Parents' and patients' preference, parents' and patients' satisfaction, and patients' adherence to therapy were all significantly better with oral montelukast compared with inhaled cromolyn. Beta-agonist use was decreased when taking montelukast, which was safe and well-tolerated.     

Ventricular structure and function in children with sickle cell disease using conventional and tissue Doppler echocardiography

Conventional 2-dimensional, M-mode, and spectral Doppler echocardiographic techniques have documented abnormal ventricular function in adults with sickle cell disease (SCD), but assessments in children are conflicting. Tissue Doppler echocardiography (TDE) provides additional information about myocardial function. Two-dimensional, M-mode, tricuspid regurgitation jet velocity (TRJV) data, and tissue Doppler echocardiographically derived myocardial velocity measurements of left ventricular (LV) and right ventricular function were taken from children with SCD compared to those of similar healthy historical controls and correlated with clinical characteristics and hemoglobin levels. Compared to 55 controls, 54 children with SCD (mean age 14.2 years, range 6 to 21) had a larger left ventricle, greater LV mass, and higher LV fractional shortening; 30% had increased pulmonary artery pressure (TRJV ≥2.5 m/s). Conventional echocardiographic measurements of LV systolic function and spectral Doppler measurements of LV and right ventricular diastolic function were essentially normal, but TDE indicated that 31% of SCD children had evidence of LV diastolic dysfunction (peak early diastolic velocity of LV inflow Doppler/peak early diastolic velocity at lateral mitral valve annulus >8), a finding that correlated with lower hemoglobin levels. Although decreasing hemoglobin levels in children with SCD correlated with LV hypertrophy, LV dilation, and LV diastolic dysfunction, long-term transfusion or hydroxyurea therapy did not affect these measurements. In conclusion, 1/3 of children with SCD had tissue Doppler echocardiographic evidence of LV diastolic dysfunction, which was correlated with hemoglobin levels. Adding serial assessments of ventricular function with TDE to conventional echocardiography may detect early cardiac changes, especially in children with severe anemia.