A Phase 3 Trial of l-Glutamine in Sickle Cell Disease.

BACKGROUND: Oxidative stress contributes to the complex pathophysiology of sickle cell disease. Oral therapy with pharmaceutical-grade l-glutamine (USAN, glutamine) has been shown to increase the proportion of the reduced form of nicotinamide adenine dinucleotides in sickle cell erythrocytes, which probably reduces oxidative stress and could result in fewer episodes of sickle cell-related pain. METHODS: In a multicenter, randomized, placebo-controlled, double-blind, phase 3 trial, we tested the efficacy of pharmaceutical-grade l-glutamine (0.3 g per kilogram of body weight per dose) administered twice daily by mouth, as compared with placebo, in reducing the incidence of pain crises among patients with sickle cell anemia or sickle ß0-thalassemia and a history of two or more pain crises during the previous year. Patients who were receiving hydroxyurea at a dose that had been stable for at least 3 months before screening continued that therapy through the 48-week treatment period. RESULTS: A total of 230 patients (age range, 5 to 58 years; 53.9% female) were randomly assigned, in a 2:1 ratio, to receive l-glutamine (152 patients) or placebo (78 patients). The patients in the l-glutamine group had significantly fewer pain crises than those in the placebo group (P=0.005), with a median of 3.0 in the l-glutamine group and 4.0 in the placebo group. Fewer hospitalizations occurred in the l-glutamine group than in the placebo group (P=0.005), with a median of 2.0 in the l-glutamine group and 3.0 in the placebo group. Two thirds of the patients in both trial groups received concomitant hydroxyurea. Low-grade nausea, noncardiac chest pain, fatigue, and musculoskeletal pain occurred more frequently in the l-glutamine group than in the placebo group. CONCLUSIONS: Among children and adults with sickle cell anemia, the median number of pain crises over 48 weeks was lower among those who received oral therapy with l-glutamine, administered alone or with hydroxyurea, than among those who received placebo, with or without hydroxyurea. (Funded by Emmaus Medical; ClinicalTrials.gov number, NCT01179217 .).

Refining the value of secretory phospholipase A2 as a predictor of acute chest syndrome in sickle cell disease: results of a feasibility study (PROACTIVE).

Acute chest syndrome (ACS) is defined as fever, respiratory symptoms and a new pulmonary infiltrate in an individual with sickle cell disease (SCD). Nearly half of ACS episodes occur in SCD patients already hospitalized, potentially permitting pre-emptive therapy in high-risk patients. Simple transfusion of red blood cells may abort ACS if given to patients hospitalized for pain who develop fever and elevated levels of secretory phospholipase A2 (sPLA2). In a feasibility study (PROACTIVE; ClinicalTrials.gov NCT00951808), patients hospitalized for pain who developed fever and elevated sPLA2 were eligible for randomization to transfusion or observation; all others were enrolled in an observational arm. Of 237 enrolled, only 10 were randomized; one of the four to receive transfusion had delayed treatment. Of 233 subjects receiving standard care, 22 developed ACS. A threshold level of sPLA2 ≥ 48 ng/ml gave optimal sensitivity (73%), specificity (71%) and accuracy (71%), but a positive predictive value of only 24%. The predictive value of sPLA2 was improved in adults and patients with chest or back pain, lower haemoglobin concentration and higher white blood cell counts, and in those receiving less than two-thirds maintenance fluids. The hurdles identified in PROACTIVE should facilitate design of a larger, definitive, phase 3 randomized controlled trial.

Clinical trial implementation and recruitment: lessons learned from the early closure of a randomized clinical trial.

BACKGROUND: The NHLBI-sponsored Sickle Cell Disease Clinical Research Network (SCDCRN) conducted a multi-center, acute intervention randomized clinical trial of two methods of Patient Controlled Analgesia for acute pain. This trial was terminated early due to low enrollment. We analyzed the perceived barriers and recruitment difficulties as reported by the coordinators and principal investigators. METHODS: Participating sites completed a missed eligibility log of subjects admitted in pain crisis throughout the study and a survey at the end of the trial. The survey covered site-specific factors, policies, and procedures in study implementation, recruitment strategies, and eligibility factors. The New England Research Institutes (NERI) collected de-identified surveys from 31 respondents at 29 of 31 participating sites. RESULTS: From December 2009 to June 2010, 1116 patient encounters for SCD and pain occurred at participating institutions: 38 subjects were enrolled (14 pediatric and 24 adults) and 34 completed the trial, below the projected 278 subjects. Fourteen sites enrolled subjects and seventeen did not. Recruitment barriers included insufficient staff, subject ineligibility or in too much pain to consent, competing protocols, and concerns regarding pain control. Recruitment methods were referrals from urgent care, SCD clinics and in house databases. No use of media or outside physicians was reported. CONCLUSION: We identified multiple barriers to patient accrual including short duration of enrollment period, protocol design, complex dosing schedule, requirement for staff availability during week-end and after hours, multiple departments' involvement, protocol acceptance, eligibility criteria, competing protocols, and limited staff. Each of these areas should be targeted for intervention in order to plan and conduct successful future clinical trials.

Exposure to hydroxyurea and pregnancy outcomes in patients with sickle cell anemia.

The Multicenter Study of Hydroxyurea in Sickle Cell Anemia (MSH) was a randomized double-blind placebo-controlled trial to test whether hydroxyurea could reduce the rate of painful crises in adults who had at least 3 painful crises per year. Because hydroxyurea is known to be carcinogenic, mutagenic, and teratogenic in animals, a major inclusion criterion in MSH was the use of contraceptives both by females and males in order to avoid exposure of the fetus to hydroxyurea. Despite this precautionary measure, some women became pregnant while taking hydroxyurea or their male partners were on hydroxyurea. We followed surviving patients who were enrolled in the original MSH trial for up to 17 years postrandomization. Our findings suggest that exposure of the fetus to hydroxyurea does not cause teratogenic changes in those pregnancies that terminate in live birth whether full-term or premature. This seems to be true whether the parent taking hydroxyurea was the mother or the father. The same argument seems to apply for exposure to opioids. However, it will take a much longer follow-up of many more hydroxyurea-exposed sickle cell disease subjects to establish the results conclusively.

Bone mass density in adults with sickle cell disease.

Sickle cell disease (SCD) leads to many complications including osteoporosis and osteopenia. We studied the prevalence and predisposing factors of low bone mass density (BMD) in adults with SCD. In this retrospective study, dual X-ray absorptiometry bone scans were used to determine BMD in the lumbar spine, femoral neck and ultra distal radius of 103 patients (73 females, 30 males, aged 15-80 years). Chart reviews and a patient questionnaire were used to collect patient characteristics, disease course and severity, and low BMD risk factors. The 79.6% of patients (mean age 36.5 +/- 12.5 years) had an abnormal BMD, with a predilection for the lumbar spine (P = 0.001). Analysis by 3 (low BMD versus very low BMD versus normal) or by 2 groups (abnormal versus normal) showed that abnormal BMD was associated with lower body mass index (BMI) (P = 0.003), lower Hb level (P = 0.001) and higher ferritin (P = 0.003). Low BMD patients were more likely to be SS, SC or Sbeta(0)thal than Sbeta(+)thal (P = 0.022). Abnormal BMD was not related to age, sex, menarche, SCD complications, number of crises, iron overload, treatment with hydroxycarbamide or desferal, renal disease, smoking or alcohol. Patients treated with hydroxycarbamide for at least 6 months were more likely to have an abnormal BMD. In this SCD population, abnormal BMD seemed to be independent of sex, age and menopause, whereas BMI, ferritin level, Hb type and level appeared to play a major role.

A model for automated screening of thalassemia in hematology (math study).

BACKGROUND: beta-thalassemia screening is primarily limited to pregnant women. The ratio of the mean corpuscular volume (MCV) and red blood cell count (RBC) can be automatically calculated with any of the newer hematology analyzers. METHODS: The results of 398 patient screens were collected. Data from the set were divided into training and validation subsets. The Mentzer ratio was determined through a receiver operating characteristic (ROC) curve on the first subset, and screened for thalassemia using the second subset. HgbA2 levels were used to confirm beta-thalassemia. RESULTS: We determined the correct decision point of the Mentzer index to be a ratio of 20. Physicians can screen patients using this index before further evaluation for beta-thalassemia (P < .05). CONCLUSION: The proposed method can be implemented by hospitals and laboratories to flag positive matches for further definitive evaluation, and will enable beta-thalassemia screening of a much larger population at little to no additional cost.

Increased prevalence of iron-overload associated endocrinopathy in thalassaemia versus sickle-cell disease.

Iron-overload associated endocrinopathy is the most frequently reported complication of chronic transfusion therapy in patients with thalassaemia (Thal). This study compared iron-overloaded subjects with Thal (n = 142; 54%M; age 25.8 +/- 8.1 years) and transfused sickle-cell disease (Tx-SCD; n = 199; 43%M, 24.9 +/- 13.2 years) to non-transfused SCD subjects (non-Tx-SCD; n = 64, 50%M, 25.3 +/- 11.3 years), to explore whether the underlying haemoglobinopathy influences the development of endocrinopathy. Subjects were recruited from 31 centres in the USA, Canada and the UK. Subjects with Thal had more evidence of diabetes (13% vs. 2%, P < 0.001), hypogonadism (40% vs. 4%, P < 0.001), hypothyroidism (10% vs. 2%, P = <0.001) and growth failure (33% vs. 7%, P < 0.001), versus Tx-SCD. Fifty-six per cent of Thal had more than one endocrinopathy compared with only 13% of Tx-SCD (P < 0.001). In contrast, Tx-SCD was not different from non-Tx-SCD. Multivariate analysis indicated that endocrinopathy was more likely in Thal than SCD [Odds Ratio (OR) = 9.4, P < 0.001], with duration of chronic transfusion a significant predictor (OR = 1.4 per 10 years of transfusion, P = 0.04). Despite iron overload, endocrinopathy was not increased in Tx-SCD versus non-Tx-SCD, suggesting that the underlying disease may modulate iron-related endocrine injury. However, because transfusion duration remained a significant predictor of endocrinopathy, these data should be confirmed in SCD subjects that have been chronically transfused for longer periods of time.

Mild hyperhomocysteinemia in adult patients with sickle cell disease: a common finding unrelated to folate and cobalamin status.

Homocysteine has associations with both vitamin insufficiency and vascular complications, and its status is therefore of interest in sickle cell disease (SCD). However, information is limited, especially in adults. We studied plasma total homocysteine (tHcy) and three of its major modifiers, cobalamin, folate, and creatinine, in 90 adult patients with SCD and 76 control subjects. The patients had higher tHcy levels than did controls (P = 0.03) and had elevated tHcy more often (20% vs. 3%, P = 0.0005). None of the hyperhomocysteinemic patients had low cobalamin or folate levels; on the contrary, patients with SCD had high folate levels more often than control subjects (32% vs. 7%; P < 0.0001). Although serum creatinine values were lower in SCD patients than in control subjects (P = 0.03), high levels also tended to occur more often (8% vs. 1%; P = 0.054). Most importantly, creatinine levels correlated significantly with tHcy (P < 0.0001) and logistic regression analyses showed creatinine to be the only significant predictor of high tHcy levels in SCD (P = 0.01). Our results show that hyperhomocysteinemia affects 20% of adults with SCD despite routine folate supplementation and is independent of folate and cobalamin status. Creatinine was the major identifiable influence on tHcy, but renal insufficiency explained only 4 of the 18 elevated tHcy levels. Longitudinal studies will be needed to determine whether the frequent hyperhomocysteinemia of SCD influences the vascular complications in SCD. If reducing tHcy becomes advisable, then interventions other than folate therapy will be needed.

Effect of hydroxyurea on mortality and morbidity in adult sickle cell anemia: risks and benefits up to 9 years of treatment.

CONTEXT: Hydroxyurea increases levels of fetal hemoglobin (HbF) and decreases morbidity from vaso-occlusive complications in patients with sickle cell anemia (SCA). High HbF levels reduce morbidity and mortality. OBJECTIVE: To determine whether hydroxyurea attenuates mortality in patients with SCA. DESIGN: Long-term observational follow-up study of mortality in patients with SCA who originally participated in the randomized, double-blind, placebo-controlled Multicenter Study of Hydroxyurea in Sickle Cell Anemia (MSH), conducted in 1992-1995, to determine if hydroxyurea reduces vaso-occlusive events. In the MSH Patients' Follow-up, conducted in 1996-2001, patients could continue, stop, or start hydroxyurea. Data were collected during the trial and in the follow-up period. SETTING: Inpatients and outpatients in 21 sickle cell referral centers in the United States and Canada. PATIENTS: Two-hundred ninety-nine adult patients with frequent painful episodes enrolled in the follow-up. Follow-up data through May 2001 were complete for 233 patients. INTERVENTION: In the MSH, patients were randomly assigned to receive hydroxyurea (n = 152) or placebo (n = 147). MAIN OUTCOME MEASURE: Mortality, HbF levels, painful episodes, acute chest syndrome, and blood cell counts. The randomized trial was not designed to detect specified differences in mortality. RESULTS: Seventy-five of the original 299 patients died, 28% from pulmonary disease. Patients with reticulocyte counts less than 250 000/mm3 and hemoglobin levels lower than 9 g/dL had increased mortality (P =.002). Cumulative mortality at 9 years was 28% when HbF levels were lower than 0.5 g/dL after the trial was completed compared with 15% when HbF levels were 0.5 g/dL or higher (P =.03 ). Individuals who had acute chest syndrome during the trial had 32% mortality compared with 18% of individuals without acute chest syndrome (P =.02). Patients with 3 or more painful episodes per year during the trial had 27% mortality compared with 17% of patients with less frequent episodes (P =.06). Taking hydroxyurea was associated with a 40% reduction in mortality (P =.04) in this observational follow-up with self-selected treatment. There were 3 cases of cancer, 1 fatal. CONCLUSIONS: Adult patients taking hydroxyurea for frequent painful sickle cell episodes appear to have reduced mortality after 9 of years follow-up. Survival was related to HbF levels and frequency of vaso-occlusive events. Whether indications for hydroxyurea treatment should be expanded is unknown.