Adekunle D. Adekile

Molecular Characterization of α-Thalassemia Determinants, β-Thalassemia Alleles, and βs Haplotypes among Kuwaiti Arabs

Using amplification, allele-specific oligonucleotide (ASO) hybridization and DNA sequencing we have documented the molecular basis of 64 α- and 123 β-thalassemia (thai) chromosomes, and the haplotypes

Morbidity, βs Haplotype and α-Globin Gene Patterns among Sickle Cell Anemia Patients in Kuwait

Admission records of children with sickle cell anemia (SS), in the two main teaching hospitals in Kuwait, were reviewed for a 1-year period. The haplotypes of 92 βs chromosomes (from 39 SS,

Avascular Necrosis of the Hip in Children with Sickle Cell Disease and High Hb F: Magnetic Resonance Imaging Findings and Influence of α-Thalassemia Trait

Avascular necrosis (AVN) of the hip is a common cause of morbidity in sickle cell disease (SCD). Its prevalence increases with age and predisposing factors include coexistent α-thalassemia trait, frequent vaso-occlusive crisis and a high hematocrit (Hct). SCD is relatively mild among Kuwaiti patients because of their elevated Hb F levels, but a subset exists with severe recurrent vaso-occlusive crises. We carried out a prospective magnetic resonance imaging (MRI) study of the hip in a group of patients being followed in the Pediatric Hematology clinics of Al-Mubarak and Al-Amiri Hospitals. The association of AVN with age, frequency of hospitalization, α-thal trait, steady-state Hb, Hct, Hb F, WBC and platelet counts was investigated. MRI was carried out with a 1.5-tesla GE unit with a super-conducting magnet. Thirty patients (19 males, 11 females) (23 SS and 7 SβThal) were studied. Their ages ranged from 6 to 17 years, with a mean of 9.8 ± 3.5 years, and Hb F from 11 to 35% with a mean of 22.8 ± 5.7%. Among the SS patients, 11 (47.8%) had coexistent α-thal trait (–3.7-kb deletion). A total of 8 (26.7%) patients (6 SS and 2 SβThal) had varying degrees of osteonecrosis of the hip. Four (36.4%) of the 11 SS patients with α-thal trait and 2 (16.7%) of those without α-thal trait had osteonecrosis. This difference is, however, not statistically significant (χ2 = 0.3, p = 0.5). While there was also no significant difference in the mean age and hematological parameters (Hb, Hct, Hb F, WBC, platelets), the SS patients with osteonecrosis had a significantly higher number of hospitalizations for vaso-occlusive crisis in the preceding 3 years than those without osteonecrosis.

Current sickle cell disease management practices in Nigeria

BACKGROUND Although Nigeria has the highest burden of sickle cell disease (SCD) worldwide, there is still variable and poor utilisation of standard-of-care practices for SCD patients in the country. METHODS This was a questionnaire survey of doctors in some dedicated SCD clinics in Nigeria in order to document the facilities available and common management practices. RESULTS There were responses from 18 clinics based in 11 institutions. The number of patients being followed in each centre ranged from 15 to approximately 11 000. All clinics provided malaria prophylaxis and folic acid routinely to their patients. Only eight clinics prescribe penicillin prophylaxis. Eight prescribe hydroxyurea to patients who can afford it when indicated. All of the centres except three have electronic cell counters, but all had access to haemoglobin electrophoresis. Three had high-performance liquid chromatography machines installed but none was being routinely used. One institution had a functioning molecular biology laboratory. There is no official newborn screening programme in the country. All had access to microbiology and chemistry laboratories. Nine institutions had CT, six had MRI and three had transcranial Doppler facilities. CONCLUSION The care available for SCD in Nigeria is still suboptimal and there is an urgent need for concerted effort to tackle the problem, but to make a significant impact on the burden of the disease would require more focus at the primary care level. Some steps to achieving this are outlined.

Variability in the fetal hemoglobin level of the normal adult.

We analyzed blood samples from more than 200 normal adults, and quantified their Hb F by cation‐exchange high‐performance liquid chromatography. In several subjects with slightly elevated Hb F (0.4–4.3%), we determined the Gγ levels in the Hb F and DNA sequence variations in the locus control region II and in the Gγ and Aγ promoters. About 25% of the ∼200 normal teenaged high school students had elevated Hb F; detailed analyses of some 20 students, selected at random, identified most as females with a homozygosity for the C→T variation at position ‐158 (Gγ). One 11‐year‐old boy was heterozygous for the A→G change at position ‐161 (Gγ); he and two of his relatives had ∼4% Hb F, high Gγ values, and a high level of (mainly) Gγ‐mRNA. Nearly 40 normal adults from Macedonia and from Georgia (mostly Caucasians) were tentatively identified as Swiss HPFH heterozygotes because slightly elevated Hb F levels were observed at least once. Many of these persons were heterozygous or homozygous for the C→T mutation at ‐158 (Gγ), and a few carried a γ‐globin gene triplication. The C→T change appears to be an important factor predisposing the adult to increased Hb F production. Evidence suggests a gene dose effect in (mildly) anemic adults; however, other factors besides the C→T change at ‐158 (Gγ), including factors not linked to the β‐globin region, may cause an increase in γ‐chain synthesis.

Influence of α‐thalassemia trait on spleen function in sickle cell anemia patients with high HbF

Spleen function was studied in a group of 20 Kuwaiti SS patients (aged 2–12 years), using 99mTc‐labeled tin colloid scintigraphy. They were screened for the α‐thalassemia determinants which are prevalent in the Arabian Peninsula [‐α (3.7 kb) deletion, α2‐globin gene polyadenylation signal (AATAAA → AATAAG) mutation, and 5′ IVS‐I splice junction pentanucleotide (GAGGTGAGG → GAGG) deletion] with a combination of polymerase chain reaction and allele‐specific oligonucleotide (ASO) hybridization techniques. The patients were divided into three groups depending on the result of their colloid uptake. Group I consisted of 7 patients (35.0%) with normally visualized spleens, Group II consisted of 5 (25.0%) with partial visualization, and in Group III there were 8 (40.0%) in whom the spleen was not visualized at all. The significant distinguishing features among those in Groups I and III were mean corpuscular volumes (MCVs) of 74.1 ± 5.1 and 90.1 ± 6.6 fl (P < 0.0001) and mean corpuscular hemoglobins (MCHs) of 22.4 ± 2.7 and 27.5 ± 4.0 pg (P < 0.05), respectively. The overall frequency of α‐thalassemia determinants in the study was 35.0%; however, the frequencies in Groups I, II, and III were 57.1, 30.0, and 18.8%, respectively. α‐Thalassemia trait, therefore, appears to be associated with normal splenic function in these patients.

Th1 and Th2 Cytokine Profiles in Sickle Cell Disease

We have investigated the levels of Th1 (IL-2 and IFN-γ) and Th2 (IL-4) cytokines in the plasma and supernatants following peripheral blood mononuclear cell culture and mitogen stimulation in a group of 39 patients with sickle cell disease (SCD) made up of 29 SS, 8 Sβ-thal and 2 Hb SD in steady state. Five SS patients were studied during 7 episodes of vaso-occlusive crisis. Twenty-four control (3 Hb AS and 21 Hb AA) were also studied; 10 were acutely ill while 14 were healthy at the time of the study. The plasma levels of IL-2 and IFN-γ were similar in the patients and the controls. However, plasma IL-4 was significantly higher among the steady-state SS patients than in the controls. While there was no significant difference in cytokine levels following mitogen stimulation in the different groups, plasma IL-2 to IL-4 and IFN-γ to IL-4 ratios were significantly lower among the steady-state SS patients, indicating a possible Th2 bias in our sickle cell patients and suggesting a possible mechanism to explain the predisposition of SCD patients to bacterial infections. However, SS patients with good splenic function showed a relative Th1 bias, which may be an additional explanation for the protection against bacterial infections in such patients.

Infectious Etiologies of Transient Neutropenia in Previously Healthy Children

Background: Healthy children presenting with neutropenia are often hospitalized and treated empirically with antibiotics without an evidence of infection. The objective of this study was to investigate the infectious causes of isolated transient neutropenia in otherwise previously healthy children. Method: A 2-year prospective study was conducted at a tertiary hospital in Kuwait. All previously healthy children (aged 1 month to 12 years) hospitalized with isolated neutropenia defined as absolute neutrophil count (ANC) ⩽ 1.5 × 109/L were enrolled in the study. Investigations to identify the infectious causes included blood and urine culture for bacteria whereas for viruses, serology for Epstein-Barr virus, cytomegalovirus, adenovirus, parvovirus and polymerase chain reaction for human herpes virus 6 and enterovirus were performed. Results: Fifty-five children were enrolled during the study. Children less than 2 years of age constituted 73% of the sample. There were 2 peaks of presentation: March–May (33%) and September–November (38%). Associated features were congested throat (56%), runny nose (53%) and cervical lymphadenopathy (20%). The median ANC on admission was 0.6 × 109/L. Associated infections were documented in 55% of enrolled children and were as follows: human herpesvirus 6, 30%; enterovirus, 23%; influenza A H1N1, 13%; parvovirus, 10%; Epstein-Barr virus, 10%; urinary tract infection, (Eshcherichia coli) 7%; and adenovirus, 7%. No serious bacterial infection was identified, and the mean time for recovery of the ANC was 16.7 ± 15 days. Conclusions: Neutropenia in previously healthy children in Kuwait is caused by demonstrable infections in 55% of cases. Majority of children will recover their ANC completely within 1 month without significant infectious complications.

Avascular necrosis of the femoral head in adult Kuwaiti sickle cell disease patients.

While sickle cell disease (SCD) is generally mild in most Kuwaitis, because of their elevated fetal Hb levels, avascular necrosis of the femoral head (AVNFH) appears to be a common complication. It was recently documented in 26.7% of Kuwaiti children with SCD. There have, however, been no previous studies of adult patients. This is a 1-year study of consecutive, steady-state SCD patients seen in the hematology clinic of Mubarak Al-Kabeer Hospital. The patients’ charts were reviewed for frequency of hospitalizations, any documented complications and steady-state complete blood count (CBC). MRI was performed using T1- and T2-weighted FATSAT sequences in coronal and axial planes with 4-mm-thick slices on a 1.5-tesla GE super-conducting magnet. Thirty-five patients were studied, consisting of 25 SS and 10 Sβ⁰Thal patients aged between 17 and 44, with a mean age of 26.7 ± 9.3 years. Seventeen (48.6%) had varying degrees of AVNFH; among the 70 hips examined, 29 (41.1%) were affected. Of the 17 patients affected, 11 (64.7%) were SS, while 6 (35.3%) were Sβ⁰Thal. There were 14 (82.4%) males and 3 (17.6%) females (χ2 = 8.6, p < 0.01). The mean age of those affected, 27.5 ± 10.7 years, was not significantly higher than that of the unaffected (26.3 ± 8.0 years). Eleven (64.7%) of those affected had a history of frequent vaso-occlusive crisis. No significant differences could be demonstrated in the mean CBC and Hb F values of the two groups; coexistent α-thal trait was not a factor in the SS group. Male gender was the only significant predisposing factor identified. While more patients with frequent vaso-occlusive crises were affected, the difference was not significant. AVNFH is, indeed, quite common among Kuwaiti SCD patients and there is a need for early institution of preventive and therapeutic protocols.

Mri Follow-up and Natural History of Avascular Necrosis of the Femoral Head in Kuwaiti Children With Sickle Cell Disease

Purpose: To document the MRI progression and the natural history of avascular necrosis of the femoral head (AVNFH) in Arab children with sickle cell disease. Patients and Methods: Twenty-three SS and 7 Sβ0Thal patients (aged 6–17 years) were screened for AVNFH between 1998 and 1999. Eight (26.7%) were identified with varying degrees of AVNFH. Seventeen of the original 30 patients have now been followed for 1 to 4 (mean 2.0 ± 1.2) years, with repeat MRI of the hips. Spin-echo T1-and T2-weighted images and T2 fat-saturation sequences were obtained using a 1.5-Tesla GE unit with superconductors. AVNFH was graded I (mild), II (moderate), or III (severe). Results: Eleven (64.7%) of the 17 patients had significant progression of their lesions; at the initial study, 9 were normal, 7 were grade I, 1 was grade II, and none was grade III. At the end of the follow-up period, two were normal, seven were grade I, one was grade II, and seven were grade III. Of the nine who were initially normal, two still had no lesions, while four were grade I and three were grade III on follow-up. Of the seven who were classified as grade I initially, four remained at grade I, one moved to grade II, and two became grade III. The one patient who was initially grade II progressed to III. Conclusions: AVNFH is a common, chronic, and unrelenting complication in children with sickle cell disease, and it is usually progressive.