Anti-inflammatory cytokines in sickle cell disease

Sickle cell disease (SCD) is a well-studied monogenetic disease with an established chronic inflammatory component. The paradigm shift towards inflammation has made the pathophysiology of SCD even more complex. Studies have shown that an imbalance between the pro-inflammatory and anti-inflammatory cytokines in SCD exists; however, the reports are skewed toward the pro-inflammatory mediators. We enumerate recent in vitro and in vivo studies on anti-inflammatory cytokines in SCD patients, and discuss the biology of anti-inflammatory cytokines including the already reported IL-2, TGF-β, and IL-10 as well as the recently discovered IL-27, IL-35 and IL-37. This review will improve the understanding of the pathophysiology of SCD and aid in the search of new therapeutic options for patients with SCD.

Perforated Duodenal Ulcer Associated with Deferasirox in a Child with β-Thalassemia Major

The oral iron chelator, deferasirox (DFX), is commonly associated with mild gastrointestinal (GI) complaints, but GI hemorrhage and ulcers have occasionally been reported. However, perforated duodenal ulcer (PDU) has been previously reported in only one patient with β-thalassemia major (β-TM) on Exjade (DFXE). We hereby report the second case of a 5-year-old Syrian patient, who recently presented with PDU while on DFXE. She was not on any other ulcerogenic medication and was negative for H. pylori and Celiac disease. She had a surgical repair and has done well. She is back on DFX, but with the film-coated tablet, Jadenu or DFXJ. Perforated duodenal ulcer should be suspected in patients with severe GI symptoms, abdominal distension and tenderness while on DFXE, especially at high doses (30+ mg/kg).

Utilization of Pneumococcal Vaccine and Penicillin Prophylaxis in Sickle Cell Disease in Three African Countries: Assessment among Healthcare Providers in SickleInAfrica

Sickle cell disease is a genetic disease with a predisposition to infections caused by encapsulated organisms, especially Streptococcus pneumoniae. Pneumococcal vaccines and prophylactic penicillin have reduced the rate of this infection and mortality in sickle cell disease. However, implementation of these interventions is limited in Africa. The objectives of the study were to assess health care providers' behaviors with the implementation of pneumococcal vaccination and penicillin prophylaxis and to identify barriers to their use. A 25-item online questionnaire was administered through SickleinAfrica: a network of researchers, and healthcare providers, in Ghana, Nigeria, and Tanzania, working to improve health outcomes of sickle cell disease in Africa. Data was collected and managed using the Research Electronic Data Capture (REDCap), tools and data analysis was done using STATA version 13 and R statistical software. Eighty-two medical practitioners responded to the questionnaire. Only 54.0 and 48.7% of respondents indicated the availability of published guidelines on sickle cell disease management and pneumococcal vaccine use, respectively, at their facilities. The majority (54.0%) perceived that the vaccines are effective but over 20.0% were uncertain of their usefulness. All respondents from Ghana and Tanzania affirmed the availability of guidelines for penicillin prophylaxis in contrast to 44.1% in Nigeria. Eighty-five percent of respondents affirmed the need for penicillin prophylaxis but 15.0% had a contrary opinion for reasons including the rarity of isolation of Streptococcus pneumoniae in African studies, and therefore, the uncertainty of its benefit. Lack of published guidelines on the management of sickle cell disease and doubts about the necessity of prophylactic measures are potential barriers to the implementation of effective interventions.

Neutrophil gelatinase-associated lipocalin as a biomarker of nephropathy in sickle cell disease

Sickle cell nephropathy (SCN) develops via altered hemodynamics and acute kidney injury, but conventional screening tests remain normal until advanced stages. Early diagnostic biomarkers are needed so that preventive measures can be taken. This study evaluates the role of neutrophil gelatinase–associated lipocalin (NGAL) as a biomarker of SCN in steady state and vaso-occlusive crisis (VOC). In this case-control study, 74 sickle cell disease (SCD) patients (37 in steady state and 37 in VOC) and 53 control subjects had hematological and biochemical measurements including plasma and urine NGAL. Univariate and logistic regression analyses were used to find the associations between variables. The receiver operating characteristic (ROC) curve was used to determine the diagnostic performance characteristics of plasma and urine NGAL for detection of VOC. Plasma and urine NGAL, urine microalbumin:creatinine ratio, and urine protein:creatinine ratio were significantly higher in VOC. Microalbuminuria was present in 17.1% steady state and 32.0% VOC patients. Microalbuminuria showed significant correlations with age, plasma NGAL, WBC, and hemolytic parameters. Area under the ROC curve for plasma NGAL was 0.69 (95%CI = 0.567–0.813; p = 0.006) and 0.86 (95%CI = 0.756–0.954; p < 0.001) for urine NGAL. Urine NGAL cut-off value of 12.0 ng/mL had 95% sensitivity and 65% specificity. These results confirm the presence of nephropathy during VOC and suggest that plasma and urine NGAL would be useful in the identification of SCN. Urine NGAL should be used as the screening biomarker, and patients with VOC and urine NGAL > 12.0 ng/mL should be selected for aggressive management to prevent progression of renal damage.

Implementing newborn screening for sickle cell disease as part of immunisation programmes in Nigeria: a feasibility study

BACKGROUND

Sickle cell disease is highly prevalent in sub-Saharan Africa, where it accounts for substantial morbidity and mortality. Newborn screening is paramount for early diagnosis and enrolment of affected children into a comprehensive care programme. Up to now, this strategy has been greatly impaired in resource-poor countries, because screening methods are technologically and financially intensive; affordable, reliable, and accurate methods are needed. We aimed to test the feasibility of implementing a sickle cell disease screening programme using innovative point-of-care test devices into existing immunisation programmes in primary health-care settings.

METHODS

Building on a routine immunisation programme and using existing facilities and staff, we did a prospective feasibility study at five primary health-care centres within Gwagwalada Area Council, Abuja, Nigeria. We systematically screened for sickle cell disease consecutive newborn babies and infants younger than 9 months who presented to immunisation clinics at these five centres, using an ELISA-based point-of care test (HemoTypeSC). A subgroup of consecutive babies who presented to immunisation clinics at the primary health-care centres, whose mothers gave consent, were tested by the HemoTypeSC point-of-care test alongside a different immunoassay-based point-of-care test (SickleSCAN) and the gold standard test, high-performance liquid chromatography (HPLC).

FINDINGS

Between July 14, 2017, and Sept 3, 2019, 3603 newborn babies and infants who presented for immunisation were screened for sickle cell disease at five primary health-care centres using the ELISA-based point-of-care test. We identified 51 (1%) children with sickle cell anaemia (HbSS), four (<1%) heterozygous for HbS and HbC (HbSC), 740 (21%) with sickle cell trait (HbAS), 34 (1%) heterozygous for HbA and HbC (HbAC), and 2774 (77%) with normal haemoglobin (HbAA). Of the 55 babies and infants with confirmed sickle cell disease, 41 (75%) were enrolled into a programme for free folic acid and penicillin, of whom 36 (88%) completed three visits over 9 months (median follow-up 226 days [IQR 198-357]). The head-to-head comparison between the two point-of-care tests and HPLC showed concordance between the three testing methods in screening 313 newborn babies, with a specificity of 100% with HemoTypeSC, 100% with SickleSCAN, and 100% by HPLC, and a sensitivity of 100% with HemoTypeSC, 100% with SickleSCAN, and 100% by HPLC.

INTERPRETATION

Our pilot study shows that the integration of newborn screening into existing primary health-care immunisation programmes is feasible and can rapidly be implemented with limited resources. Point-of-care tests are reliable and accurate in newborn screening for sickle cell disease. This feasibility study bodes well for the care of patients with sickle cell disease in resource-poor countries.

FUNDING

Doris Duke Charitable Foundation, Imperial College London Wellcome Trust Centre for Global Health Research, and Richard and Susan Kiphart Family Foundation.

Barriers to the use of hydroxyurea in the management of sickle cell disease in Nigeria

Hydroxyurea (HU) is a well-known Hb F-inducing agent with proven clinical and laboratory efficacy for patients with sickle cell disease. However, concerns about its long-term safety and toxicity have limited its prescription by physicians and acceptability by patients. Thus, this study aims to evaluate clinician's barriers to the use of HU in the management of patients with sickle cell disease in Nigeria. An online survey targeted physicians in pediatrics, hematology, medicine, family medicine and general medical practice managing sickle cell disease in Nigeria. The survey was in four sections: demographic, knowledge and experience with HU, and barriers to the use of HU. Ninety-one (73.0%) of 123 contacts completed the survey. Seventy-three percent and 74.0% of the respondents noted that HU reduced transfusion rates and improved overall quality of life (QOL) of patients, respectively. While the majority of the practitioners (55.6%) see between 10-50 patients per month, most (66.7%) write <5 prescriptions for HU per month. Lack of a national guideline for use of HU, especially in children (52.0%), concern for infertility (52.0%), and safety profile of HU in pregnancy and lactation (48.2%), top the factors considered by the respondents as major barriers to the use of HU. Hydroxyurea is grossly under prescribed in Nigeria, despite that the vast majority of physicians who attend patients with sickle cell disease know about its clinical efficacy. Evidence-based clinical practice guidelines could be explored as a way to standardize practices and improve confidence of practitioners to improve physicians' prescription of HU in the management of sickle cell disease.

The Sub-Phenotypes of Sickle Cell Disease in Kuwait

Kuwaiti patients with sickle cell disease generally have a mild phenotype, but exhibit considerable heterogeneity, in spite of high Hb F levels. We have carried out a cross-sectional study of patients with sickle cell disease in the five major hospitals in Kuwait. Details of their hemoglobin (Hb) genotypes, clinical presentations and complications are presented. The study was over a span of 3 years and involved 396 patients, made up of 351 (88.6%) Kuwaitis and 45 (11.4%) expatriates. They were aged <1 to 73 years. Hb SS (β^S/β^S) was the most common (in 246 patients, i.e. 62.1%) followed by Hb S (HBB: c.20A>T)-β-thalassemia (Hb S-β-thal) in 138 (34.8%) and 11 (2.8%) Hb S/Hb D-Punjab (HBB: c.364G>C). Hb F ranged from 1.0 to 55.0%, with a mean of 21.2 ± 9.8%. The most common presentation was vaso-occlusive crises (VOCs), with 230 (54.8%) having had at least one prior to the study with 54 (13.2%) and 74 (18.9%) having between 2-3 and >3 VOCs, respectively. Hydroxyurea (HU) was prescribed to 157 (39.6%) patients. The most common complication was gallstones in 131 (33.1%), followed by acute splenic sequestration in 26.8% and avascular necrosis of the femoral head in 21.2% patients, respectively. Stroke, priapism and leg ulcers were rare. Gallstones, splenic sequestration and osteonecrosis were significantly more common in patients aged >16 years. Patients with Hb S-β-thal were similar to those with Hb SS in their clinical profiles. The phenotypic expression of sickle cell disease in Kuwaitis is unique in many respects. The role(s) of Hb F and other genetic modifiers require further elucidation.

Neutrophilic Panniculitis in a child with MYSM1 deficiency

Neutrophilic panniculitis (NP) with myelodysplasia has been described in adults but not in children. We report a case of NP associated with myelodysplasia in a child with MYSM1 deficiency, a newly described syndrome with primary immunodeficiency (PI), bone marrow failure, and developmental aberrations.

Risk of avascular necrosis of the femoral head in children with sickle cell disease on hydroxyurea: MRI evaluation

BACKGROUND

There are conflicting reports on the role of hydroxyurea (HU) in the pathogenesis of avascular necrosis of the femoral head (AVNFH) in patients with sickle cell disease (SCD).

PROCEDURE

The present study is a prospective cohort study of Kuwaiti children with SCD who were treated with HU. They had magnetic resonance imaging of the hips before starting HU and at regular intervals during a follow-up period, ranging from 1 to 15 years.

RESULTS

There were 40 patients (18 SS, 19 Sβ0-thalassemia, and three SD genotypes), aged 6-20 years. Pre-HU, 11 (27.5%) had varying grades of AVNFH, while post HU, the prevalence was 32.5%. Two patients developed new lesions during the study, while five (45.5%) that had lesions pre-HU remained static, another five (45.5%) progressed, and one (9%) improved radiologically. The older patients who had been on HU the longest were more likely to deteriorate. The only hematological parameter that was consistently associated with AVNFH was the reticulocyte count.

CONCLUSIONS

The frequency and rate of progression of AVNFH in this study is much less than that previously reported for our patients not treated with HU. There is no evidence that HU therapy is a risk factor for AVNFH. It may, in fact, prevent new lesions and deter the progression of existing AVNFH.

Evaluation of sociodemographic, clinical, and laboratory markers of sickle leg ulcers among young nigerians at a tertiary health institution

Background

Sickle leg ulcer (SLU) is a chronic and debilitating complication of sickle cell disease (SCD) associated with huge physical and psychosocial discomfort. The occurrence of SLU has remained steady despite successful preventive strategies and advances in SCD care. Although multifactorial factors have been implicated in SLU, these are not fully understood, and data on how these relate to young Nigerian SCD patients are scanty.

Aims

This study aims to evaluate the sociodemographic, clinical, and laboratory markers of SLU in a young Nigerian SCD cohort.

Patients and Methods

This study involved 109 young SCD patients and 67 healthy peers. The sociodemographic and laboratory parameters of the participants were examined in addition to the evaluation of the SCD cohort for SLU.

Results

Only the HbSS patients had SLU. This was found in six of them giving a prevalence of 5.9% (6/101). Their median age was 17, range 14-21 years. There was a preceding history of trauma in 4 (66.7%), and this included a case of traditional scarifications for local therapeutic purposes. Two of the three (66.7%) males with SLU also had priapism (P = 0.0132). Patients with SLU were older, had less frequent bone pain crises, and significantly belonged to the low socioeconomic class (P < 0.05). Although patients with SLU had relatively higher lactate dehydrogenase, platelet count, aspartate transaminase, bilirubin, white blood cell, and lower Hb concentration and HbF, these did not attain statistical significance (P > 0.05).

Conclusion

This study confirms that SLU is common among young SCD patients with HbSS genotype, low socioeconomic background, and older age. It also suggests that SLU could be more related to hemolysis-associated SCD phenotypes among the patients.

Comparative study of the growth and nutritional status of Brazilian and Nigerian school-aged children with sickle cell disease

Background

Comparative studies of patients in different sociogeographic/ecological zones may unravel potential environmental and nutritional factors influencing disease phenotype. In sickle cell disease (SCD), differential access to comprehensive care may influence their growth and nutritional status.

Methods

From June 2015 to February 2016, steady-state nutritional parameters of 109 Brazilian and 95 Nigerian children with SCD attending routine clinic visits at Universidade Federal de São Paulo, Brazil and Obafemi Awolowo University Teaching Hospital, Ile-Ife (Ilesa unit), respectively, were compared.

Results

A relatively high proportion of the children in both centres (23.5%) were wasted [body-mass index (BMI)-for-age z-score<-2). BMI-for-age z-score, height-for-age z-score, upper arm fat area and fat percentage were lower in the Nigerian cohorts. More Nigerians, 29.5% (28/95) against 18.3% (20/109) were wasted, and had short stature, [12.6% (12/95) vs. 3.7% (4/109)] than Brazilians. A higher proportion of Brazilian patients were overweight or obese (9.2 vs. 4.3%), and taller for age (15.6 vs. 8.4%). None of the Nigerian patients had severe vitamin D deficiency, only 12.6% (12/95) had suboptimal vitamin D and 1.1% (1/95) had low serum zinc levels, unlike 79.8% (87/109) of the Brazilian patients with suboptimal vitamin D and 10.1% (11/109) with low zinc.

Conclusion

Undernutrition is still prevalent among the two cohorts. Nigerian patients were thinner and had reduced linear growth for age. This observation justifies the continued need for specialized nutritional care for children with SCD. In addition to hydroxyurea therapy, research is needed to determine appropriate nutritional intervention and exercise regimens for these children.

A Multi-centre Survey of Acceptability of Newborn Screening for Sickle Cell Disease in Nigeria

Background

Sickle cell disease (SCD) is a major genetic disease that manifests early in life and may lead to significant morbidities. One of the health care services that have been effective in reducing the burden of SCD in developed countries is newborn screening (NBS) followed by pneumococcal vaccines, penicillin prophylaxis, and hydroxyurea treatment. Yet, in sub-Saharan African countries, where about 75% of annual affected babies worldwide are born, NBS programmes are largely unavailable. It is not clear whether this is due to technical challenges associated with setting up such programmes, or significant cultural and social barriers to its acceptance in such settings.

Objective

Our aim was to ascertain the attitudes to and acceptability of NBS in Nigeria among various socio-demographic groups including health professionals, undergraduate students, parents of children with SCD and SCD patients.

Methods

Data on socio-demographic characteristics, knowledge of SCD and attitude towards NBS were collected using a semi-structured pre-tested questionnaire from April to July 2014 across 15 health institutions and university campuses in Nigeria. Data were collected from 1,301 respondents across Nigeria.

Results

There was good knowledge of SCD as an inherited blood disorder. Although 86% of respondents (n = 1,119) supported NBS, there was a statistically significant relationship between support for NBS and age (p = 003), educational status (p = 000) and religion (p = 000).

Conclusion

This study suggests that there is a good acceptability of NBS across Nigeria. The main barriers to its use are likely to be financial and practical, rather than social or cultural.

Correlates of Pulmonary Function in Children with Sickle Cell Disease and Elevated Fetal Hemoglobin

OBJECTIVE

The current study was carried out to compare pulmonary function tests (PFTs) in pediatric Kuwaiti sickle cell disease (SCD) patients to age-matched normal controls and to investigate the association of PFTs with selected clinical and laboratory parameters. Subjects andMethods: There were 38 patients with SCD and 36 controls in the study. The patients were recruited from the Pediatric Hematology Clinics of Mubarak Al-Kabeer and Al-Amiri Hospitals, Kuwait, and were studied in steady state. The controls were healthy, non-sickle cell siblings of the patients. Forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), total lung capacity, and other PFT parameters were obtained using a constant-volume, variable-pressure, body plethysmograph. Hemoglobin, fetal hemoglobin, serum bilirubin, and lactate dehydrogenase were determined using standard methods.

RESULTS

The mean ages of the patients and controls were 10.5 ± 3.2 and 10.5 ± 3.5 years, respectively. The FEV1% predicted of 84.1 ± 15.4% among the patients was significantly lower than the 92.1 ± 11.8% in the controls (p = 0.003). The FVC% predicted was also significantly lower (p = 0.022) in the patients than in the controls, although the values were generally within the normal range. There was no association of FEV1 with pain phenotype, acute chest syndrome (ACS), or blood transfusions. Also, there was no significant correlation with reticulocytes, bilirubin, or lactate dehydrogenase.

CONCLUSIONS

In this study, changes in PFT, especially FEV1, developed early in the SCD patients. There was no demonstrable association with frequent vaso-occlusive crisis, ACS, and other variables. Hence, there is a need for follow-up studies with serial PFTs to identify vulnerable patients, who might need intervention to prevent early mortality.

Preliminary Evaluation of a Point-of-Care Testing Device (SickleSCAN™) in Screening for Sickle Cell Disease

Sickle cell disease affects about 150,000 births annually in Nigeria. Early diagnosis is hampered by factors such as centralized and urban localization of laboratories, high cost of diagnostic equipment and inadequate skilled manpower to operate them. The need for a low-cost, portable, easy-to-use diagnostic test for sickle cell disease is critical, especially in resource-poor countries. In this study, we evaluated the performance characteristics of a novel point-of-care testing device (SickleSCAN™), and its acceptability and feasibility, as a possible screening tool for sickle cell disease. In the first phase, we assessed the performance characteristics of SickleSCAN™ by evaluating 57 subjects comprising both children and adults attending a primary health center, for Hb SS (β^S/β^S; HBB: c.20A>T), Hb SC (β^S/β^C; HBB: c.19G>A) and Hb AS (β^A/β^S) using SickleSCAN™, cellulose acetate electrophoresis (CAE) and high performance liquid chromatography (HPLC). Performance characteristics such as diagnostic sensitivity and specificity were compared to HPLC as a standard method. We subsequently undertook a second phase wherein the acceptability and feasibility of the device for sickle cell disease screening, was evaluated using semi-structured and structured questionnaires among 197 healthcare personnel and 221 subjects, respectively. Sickle cell disease was carried by 3.4% of the subjects. The diagnostic sensitivity, specificity and test efficiency of SickleSCAN™ for sickle cell disease (Hb SS and Hb SC), were 100.0, 98.2 and 98.2%, respectively. Findings from this study showed SickleSCAN™ to be a viable screening tool that can easily be applied in community-based screening for early diagnosis of sickle cell disease with little expertise and low cost.

Relationship between serum 25-hydroxyvitamin D and inflammatory cytokines in paediatric sickle cell disease

BACKGROUND

Alteration in the concentration of inflammatory cytokines may contribute to pathogenesis in sickle cell anaemia (SCA). Vitamin D may suppress pro-inflammatory cytokines and enhance anti-inflammatory cytokines.

OBJECTIVE

To compare steady state levels of pro-and anti-inflammatory cytokines of Nigerian SCA children with age- and sex-matched healthy controls, and determine the relationship with 25-hydroxyvitamin-D (25-OHD). Effects of three months of vitamin D supplementation on cytokines of SCA children with suboptimal 25-OHD were also evaluated.

METHODS

Serum 25-OHD, IL-1β, 2, 6, 8, 11, 12, 13, 17, 18 of 95 SCA children and 75 matched controls were determined using HPLC. The 12 SCA children with suboptimal 25-OHD received 2000IU of vitamin D daily for 3months, and their post supplementation cytokines and 25-OHD levels were compared with the baseline values.

RESULTS

IL-2, 6, 8, 12, 17 and 18 were higher in SCA children than the controls (p≤0.001), but no significant variation in IL-11 and 13 (p=0.131 and 0.057 respectively). Patients with suboptimal serum 25-OHD had higher IL-6, 8 and 18 (p=0.003, 0.010 and 0.002 respectively) and lower levels of IL-11 (p=0.005). Significant positive treatment effects were observed: post-supplementation, serum 25-OHD increased by 23.3ng/mL, p<0.001; proinflammatory cytokines IL-2, 6, 8, 17 and 18 (p<0.001) were reduced and anti-inflammatory cytokine IL-11 was increased, p<0.001.

CONCLUSIONS

Suboptimal 25OHD is associated with enhanced levels of pro-inflammatory markers in children with SCA. Three months of daily vitamin D supplementation reversed the trend. Hence; Vitamin D supplementation may reduce the inflammatory milieu and serve as an anti-inflammatory agent in the management of SCA.

Sickle cell disease clinical phenotypes in children from South-Western, Nigeria

BACKGROUND

The clinical phenotypes of children with sickle cell disease (SCD) are poorly described in many sub-Saharan countries including Nigeria.

OBJECTIVES

The objective was to highlight various clinical phenotypes of SCD in children and investigate the influence of sociodemographic indices on the development of SCD complications.

METHODS

We carried out a cross-sectional study of 240 pediatric patients attending the sickle cell clinic and the emergency room in a teaching hospital in South-Western Nigeria over a 12-month period. The clinical phenotypes and severity of the disease were documented, and the influence of sociodemographic variables was investigated.

RESULTS

The five leading clinical phenotypes in our patients were significant pain episodes, that is, vaso-occlusive crisis in 159 (66.3%); anemic crisis in 62 (25.8%); severe bacterial infections, 57 (23.8%); acute chest syndrome (ACS), 27 (11.3%) and stroke, 7 (2.9%). Forty-two (33.1%) had a previous history of dactylitis (hand-foot syndrome). Other clinical phenotypes such as avascular necrosis of the femur, 4 (1.7%); nephropathy, 2 (0.8%); priapism, gallstone and chronic leg ulcer, one (0.4%) each, were not commonly seen. More children with a history of asthma had ACS. Furthermore, high steady-state white blood cell count was associated with severe disease.

CONCLUSION

The clinical phenotypes of SCD in children from South-Western Nigeria are highly variable with the disease manifesting very early and about 10% having significant complications. Sociodemographic characteristics appear to have little influence on the development of SCD complications among our patients, but age and low-socioeconomic class are associated with anemic crisis.

Transthoracic echocardiography and 6-minute walk test in Kuwaiti sickle cell disease patients

OBJECTIVE

The aim of this study was to investigate cardiac abnormalities in Kuwaiti sickle cell disease (SCD) patients using markers such as tricuspid regurgitant jet velocity (TRJV), pulmonary artery systolic pressure (PASP), and the 6-minute walk (6MW) test and correlate these findings with clinical, hematological, and biochemical parameters.

MATERIALS AND METHODS

Seventy-three patients with SCD and 70 matched controls were studied. The cardiac status was investigated using transthoracic echocardiography in 57 patients; the 6MW test was carried out in patients and controls. Complete blood counts and hemolytic parameters were assessed.

RESULTS

Reticulocytes, bilirubin, and lactate dehydrogenase were significantly higher (p < 0.0001) in patients, while hemoglobin (Hb) and haptoglobin were lower (p < 0.0001) than in controls. The mean fetal Hb among patients was 15.85 ± 8.7%. Of the 57 patients, 14 (24.5%) and 15 (26%) had mild tricuspid and mitral regurgitation, respectively. The mean ejection fraction, TRJV, and PASP were 63.9 ± 6.3%, 1.7 ± 0.5 m/s, and 23.0 ± 7.3 mm Hg, respectively. Three (5.2%) patients had mildly raised TRJV (2.6-2.97 m/s, normal range <2.5 m/s) while 8 (14%) had high PASP (mean 35.3 ± 5.1 mm Hg, normal range <30 mm Hg). Hb, hematocrit, and reticulocytes were different (p = 0.010, p = 0.006, and p = 0.011, respectively) between patients with normal and high PASP. All 3 patients who had a high TRJV had a high PASP, and 2 of these patients died during follow-up. The systolic and diastolic blood pressure, oxygen saturation before and after the 6MW test, and distance walked were lower (p = 0.006, p = 0.000, p = 0.002, p = 0.000, and p = 0.000, respectively) in patients compared to controls.

CONCLUSION

Raised PASP was common in Kuwaiti SCD patients while raised TRJV was not.

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.

The proinflammatory cytokine GM-CSF downregulates fetal hemoglobin expression by attenuating the cAMP-dependent pathway in sickle cell disease

Although reduction in leukocyte counts following hydroxyurea therapy in sickle cell disease (SCD) predicts fetal hemoglobin (HbF) response, the underlying mechanism remains unknown. We previously reported that leukocyte counts are regulated by granulocyte-macrophage colony-stimulating factor (GM-CSF) in SCD patients. Here we examined the roles of GM-CSF in the regulation of HbF expression in SCD. Upon the analysis of retrospective data in 372 patients, HbF levels were inversely correlated with leukocyte counts and GM-CSF levels in SCD patients without hydroxyurea therapy, while HbF increments after hydroxyurea therapy correlated with a reduction in leukocyte counts, suggesting a negative effect of GM-CSF on HbF expression. Consistently, in vitro studies using primary erythroblasts showed that the addition of GM-CSF to erythroid cells decreased HbF expression. We next examined the intracellular signaling pathway through which GM-CSF reduced HbF expression. Treatment of erythroid cells with GM-CSF resulted in the reduction of intracellular cAMP levels and abrogated phosphorylation of cAMP response-element-binding-protein, suggesting attenuation of the cAMP-dependent pathway, while the phosphorylation levels of mitogen-activated protein kinases were not affected. This is compatible with our studies showing a role for the cAMP-dependent pathway in HbF expression. Together, these results demonstrate that GM-CSF plays a role in regulating both leukocyte count and HbF expression in SCD. Reduction in GM-CSF levels upon hydroxyurea therapy may be critical for efficient HbF induction. The results showing the involvement of GM-CSF in HbF expression may suggest possible mechanisms for hydroxyurea resistance in SCD.

Limitations of Hb F as a phenotypic modifier in sickle cell disease: study of Kuwaiti Arab patients

Sickle cell disease is characterized by phenotypic heterogeneity and many genetic modifiers have been identified with elevated Hb F being the most recognized ameliorating factor. Kuwaiti sickle cell disease patients carry the India/Arab chromosomal haplotype, which is associated with elevated Hb F (on average ~22%) on account of the Xmn1 site in the (G)γ-globin gene promoter. Most patients had either Hb SS or Hb S-β(0)-thalassemia (β(0)-thal) and there are a few Hb SD compound heterozygotes. We have carried out longitudinal clinical studies of these patients to document the pattern of morbidity, spleen function, brain and hip magnetic resonance imaging (MRI) for prevalence of silent brain infarcts and avascular necrosis of the femoral head (AVNFH), respectively. In addition, pulmonary function, SPECT (single photon emission computerized tomography) brain cerebral blood flow and response of selected patients to hydroxyurea (HU) treatment were also studied. The Hb SS and Hb S-β-thal patients have a generally mild phenotype compared to sickle cell disease in other populations and most patients do not have their first pain crisis until about the age of 4 years. Spleen function is retained till late childhood; pneumococcemia and other severe bacterial infections are rare. Overt stroke and silent brain infarcts are uncommon in childhood (~3% prevalence) although SPECT reveals cerebral blood flow deficits in ~30%. Avascular necrosis of the femoral head is, however, common with a prevalence of ~26% in children and 50% in adults. There is brisk response to HU in patients with frequent pain crises, with marked increases in Hb F levels. Patients who are compound heterozygotes for Hbs S and D-Los Angeles, have the most severe phenotype despite Hb F levels of >20% and Hb S <30%. In conclusion, although the patients have a uniformly elevated Hb F level, there are still considerable phenotypic heterogeneity and other modulating genetic factors that require further studies.

Haptoglobin gene polymorphisms in sickle cell disease patients with different βS-globin gene haplotypes

OBJECTIVE

To investigate the prevalence of haptoglobin (Hp) gene alleles in Kuwaiti sickle cell disease (SCD) patients, who generally have a mild phenotype, and compare the pattern to Nigerian SCD patients whose SCD phenotype is more severe.

SUBJECTS AND METHODS

Hp genotyping was carried out in a group of 82 and 54 SCD patients from Kuwait and Nigeria, respectively, and appropriate Hb AA controls. The Hp genotyping was done using a PCR technique followed by agarose gel electrophoresis.

RESULTS

The frequency of the Hp-2 allele was 73.8% among Kuwaiti SCD patients, while the Hp-1 allele predominated among Nigerian patients (60.7%). However, the differences were not significant (p > 0.05) when the allele distributions were compared between Kuwaiti SCD and their AA counterparts or between Nigerian SCD and their AA controls. There was no association of Hp-2 allele with frequent vaso-occlusive crisis among the Kuwaiti SCD patients.

CONCLUSION

The distribution of Hp alleles appears to follow ethnic and geographical trends. Their role in the pathophysiology of pain crisis is not clear.

Chromosome 22q11.2 deletion presenting with immune-mediated cytopenias, macrothrombocytopenia and platelet dysfunction

OBJECTIVE

To report a case of chromosome 22q11.2 deletion presenting with large platelets, platelet dysfunction, immune-mediated thrombocytopenia and neutropenia, in addition to other features of the disease.

CASE PRESENTATION AND INTERVENTION

The patient presented in the neonatal period with tetralogy of Fallot, subtle dysmorphic features and thrombocytopenia. Fluorescent in situ hybridization analysis confirmed the diagnosis of chromosome 22q11.2 deletion. Further investigations showed immune thrombocytopenia and neutropenia in addition to reduced expression of platelet GPIb and abnormal platelet aggregation studies. CD4:CD8 ratio was reversed. His cardiac abnormality was successfully corrected surgically. He had mild recurrent bacterial infections. Recurrent epistaxis was becoming increasingly more severe, and he had cognitive developmental and speech delay. His serum calcium, phosphorus and parathormone have remained normal.

CONCLUSIONS

Immune thrombocytopenia can coexist with macrothrombocytopenia and platelet dysfunction in chromosome 22q11.2 deletion and may present with significant bleeding episodes.

Technetium 99m-diethylene triamine penta-acetic acid aerosol clearance in the evaluation of pulmonary involvement in sickle cell disease

BACKGROUND

Pulmonary clearance of inhaled technetium (Tc) 99m-labeled diethylene triamine penta-acetic acid (DTPA) aerosol is a sensitive non-invasive marker of alveolar permeability and patients with interstitial lung diseases show enhanced clearance. However, a previous study in adult patients with diabetes mellitus showed delayed clearance.

OBJECTIVES

To investigate DTPA clearance in steady-state, otherwise healthy adult sickle cell disease (SCD) patients and correlate it with pulmonary function tests (PFTs), hematologic and clinical parameters.

MATERIALS AND METHODS

The subjects were randomly selected from the Hematology Clinic of Mubarak Hospital, Kuwait. Hematologic and pulmonary function data were collected with standard methods. DTPA radio-aerosol clearance studies were performed using ultrafine nebulizer containing 35 mCi (1295 MBq) of Tc 99m-DTPA in its reservoir and t(1/2) clearance in minutes was determined. Average values for both lungs were calculated and compared with normal values for our population.

RESULTS

Forty-three subjects (24 SS and 19 S-beta(0)thal) aged between 16 and 45 yr (mean of 27.1 +/- 9.7) were studied. Twenty-two subjects (51.2%) had delayed, while only 10 (23.3%) showed enhanced DTPA clearance. Patients with enhanced clearance showed better PFTs than those with normal or delayed clearance. There was significant negative correlation of DTPA clearance with forced expiratory volume in 1 s, forced vital capacity and total lung capacity and significant positive correlation with age.

CONCLUSIONS

Majority of adult SCD patients have delayed DTPA clearance unlike in inflammatory lung diseases, but similar to diabetes mellitus. DTPA clearance may be a useful modality for monitoring pulmonary involvement in SCD.

HLA-DRB1 alleles in Hb SS patients with avascular necrosis of the femoral head

Strong associations have been established between various HLA alleles and different complications of sickle cell disease (SCD). Recently, the HLA-DRB1*03 allele was shown to be associated with susceptibility to stroke while the HLA-DRB1*02 allele may be protective. While stroke and silent brain infarcts (SBI) are unusual in Kuwaiti children with SCD, avascular necrosis of the femoral head (AVNFH) is quite common. The modulatory association factors must still be elucidated. An investigation of HLA-DRB1 alleles was carried out in a group of 68 Kuwaiti SS patients, of age 7-44 years, of whom 20 (29.4%) had AVNFH, confirmed by magnetic resonance imaging. A group of 167 apparently healthy age- and sex-matched individuals served as controls. Comparison of the HLA alleles between the whole SS group and the controls showed a significant over-representation of DRB1*01 (P < 0.01) and DRB1*10 (P < 0.05) in the patient group. No significant differences in the allele frequencies in the SS patients with or without AVNFH were observed. It therefore appears that the HLA-DRB1 locus does not play a significant role in the pathogenesis of AVNFH Kuwaiti patients.

Pulmonary function studies in Kuwaiti children with sickle cell disease and elevated Hb F

Conflicting ventilatory defects have been reported in children with sickle cell disease (SCD). In Kuwait, the disease is relatively mild with a low incidence of acute chest syndrome and other complications, presumably due to the Arab-Indian haplotype chromosomal background and elevated Hb F levels. There have been no previous studies of pulmonary function in patients with this haplotype. Pulmonary function test (PFT) was carried out on 28 steady state children with SCD (21 homozygous sickle cell (SS), seven S beta(o) thal) and two group of controls: 17 age- and sex-matched healthy children and 10 children with HbH disease. The charts of the SCD patients were reviewed for frequency of acute chest syndrome and vaso-occlusive crisis. The mean values of forced vital capacity (FVC) (83.2 +/- 11.9 vs. 91.2 +/- 11.7) and vital capacity (VC) (81.5 +/- 11.8 vs. 90.5 +/- 10.9) were significantly lower in the SS patients compared with healthy controls (p < 0.05). Similarly, these values were significantly lower than in those of the HbH group (p < 0.001 for VC and p < 0.01 for FVC). The mean forced expiratory volume in 1 s (FEV1) was lower in SS patients (86.4 +/- 11.5) compared with healthy controls (94.2 +/- 14.2), but the difference was not significant (p = 0.07). Also, the FEV1 was significantly lower in SS patients than in the HbH group (p < 0.001). There was no significant difference in the PFT parameters between SS patients with acute chest syndrome and those without. Although patients with frequent vaso-occlusive crisis had lower PFT parameters, the differences were not significant in comparison to those with infrequent crisis. This study revealed an early restrictive and obstructive pulmonary function pattern in steady state children with SCD. The finding also indicates that the changes of PFT parameters in SS patients could not be attributed to anaemia per se as patients with HbH who also have chronic anaemia did not show similar changes. This observation underscores the early occurrence of pulmonary involvement, even in patients with an otherwise relatively mild SCD.

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 SbetaThal 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.

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 Sbeta(0)Thal 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 Sbeta(0)Thal. There were 14 (82.4%) males and 3 (17.6%) females (chi(2) = 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 alpha-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.

Silent brain infarcts in adult Kuwaiti sickle cell disease patients

Although overt stroke is a common complication of sickle cell disease (SCD), its incidence is very low in Kuwaiti patients. On the other hand, the prevalence of silent brain infarcts, which is reported to be about 17-20% in American patients, has not been documented in adult Kuwaiti patients. This is a 1-year study of consecutive, asymptomatic SCD patients seen in the hematology clinic of Mubarak Al-Kabeer Hospital. Patients with a past history of seizure or any other neurological abnormality were excluded. The patients' charts were reviewed for frequency of hospitalizations, any documented complications, and steady-state CBC. MRI was done with a 1.5-Tesla unit with super-conducting magnet. T1- and T2-weighted sagittal and axial sections and proton-density axial images were obtained in 5-mm-thick sections. Thirty-five patients were studied, made up of 25 SS and 10 Sbeta(0)Thal, aged between 17 and 44 years, with a mean age of 26.9 +/- 9.3 years. MRI findings consistent with infarcts were found in 7 (20.0%) patients-6 SS and 1 Sbeta(0)thal-with a mean age of 31.8 +/- 8.2 years, which was significantly higher (P < 0.05) than the mean age of the unaffected group (25.1 - 9.0 years). There were also no differences in the mean Hb, Hb F, or any other hematological parameter in the two groups. Among the affected 6 SS, 2 had co-existent alpha-thal trait. It is interesting that, while silent infarcts are prevalent in young American patients, it is in the older age group that they occur in Kuwaiti patients. Further studies are needed to investigate the factors modulating this heterogeneity.

Silent brain infarcts are rare in Kuwaiti children with sickle cell disease and high Hb F

Overt stroke is rare among sickle cell disease (SCD) patients in Kuwait. However, there are no previous studies of silent cerebral infarcts, which have been described in up to 20% of American children with Hb SS. We have carried out a prospective brain MRI study among otherwise normal SCD patients, who were consecutive patients seen in a 1-year period to document the prevalence of silent cerebral infarcts in children with sickle cell disease in Kuwait. Any patient with a previous seizure or other neurological abnormality was excluded. MRI was done with a 1.5 Tesla unit with super-conducting magnet. T1- and T2-weighted sagittal and axial sections and proton density axial images were obtained in 5-mm thick sections. The study group consisted of 30 (23 SS and 7 Sbeta(0)Thal) patients-19 males and 11 females-whose ages ranged from 6 to 17 (mean of 9.8 +/- 3.5) years. Hb F ranged from 11% to 35% with a mean of 22.8% +/- 5.7%. Only one patient, a 10-and-a-half-year-old boy with Hb SS, showed hyperintense signals in the parietal white matter, consistent with small infarcts, thus giving a prevalence of 3.3%. Silent brain infarcts are uncommon in our patients, and the protective factors remain to be fully elucidated.

Temporal sequence of splenic dysfunction in sickle cell disease

Sickle cell patients develop splenic dysfunction early in the course of their disease as shown by failure to visualize the organ on technetium-99m colloid scintigraphy. However, preliminary studies from our center have shown that, when the spleen is not demonstrable on colloid uptake, it may be visualized on technetium-99m heat-denatured RBC scintigraphy. With time, however, the spleen can no longer be visualized with both tests in many patients. We have studied 46 patients aged 2 to 16 years, which included 36 SS, 7 Sbeta(0) thal, and 3 SD. Eighteen (39.1%) had normal splenic colloid uptake (Group 1), 15 (32.6%) had partial uptake (Group 2), and 13 (28.3%) had absent uptake (Group 3). When the patients in Group 1 were compared to those in the two other groups, there was no significant difference in the mean age and Hb F values. However, the mean Hb of 10.2 g/dl in Group 1 was significantly higher than the value of 9.0 g/dl in the other two groups. In addition, 60% of the SS patients with normal uptake and 40% of those with partial or absent uptake had co-existing alpha-thal trait; the difference in this proportion is significant (chi(2) = 85, P < 0.0001). Heat-denatured RBC scintigraphy was carried out on five patients in Group 2, and the spleen was visible in all, while of 12 children in Group 3, the spleen was visible only in 4 patients. This study demonstrates that the phagocytic function of the spleen, which is tested by colloid uptake, is the first to be lost while the filtration function, tested by denatured RBC uptake, persists for much longer. This finding may have significant implications for the clinical symptomatology and therapeutic strategies of sickle cell disease.

Hemoglobin electrophoresis and hemoglobinopathies in Kuwait

OBJECTIVES

To analyze the results of hemoglobin electrophoresis (HE) in the routine laboratory of a tertiary hospital in Kuwait and to review the common types of hemoglobinopathies prevalent in the country.

METHODS

This was a prospective study of HE performed on 2,386 samples in Mubarak Al-Kabeer Hospital, which serves more than 30% of the population of Kuwait, from June 1997 to May 1998.

RESULTS

Of the 2,386 HE tests, only 561 (23.5%) had abnormal hemoglobin genotypes. The most commonly identified hemoglobinopathies were beta-thalassemia minor (14%), sickle cell trait (6%), sickle cell anemia (0.9%), S beta zero thal (0.8%) and S beta + thal (0.8%). Two rare hemoglobin variants, Hb DPunjab and Hb E, were encountered.

CONCLUSION

HE yielded only 23.5% abnormal results, thus indicating the need to streamline requests for the test. The test should be limited to patients with hematological and clinical features suggestive of hemoglobinopathies or to individuals with a positive family history.

Avascular necrosis of the hip in children with sickle cell disease and high Hb F: magnetic resonance imaging findings and influence of alpha-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 alpha-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, alpha-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 SbetaThal) 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 alpha-thal trait (-3.7-kb deletion). A total of 8 (26.7%) patients (6 SS and 2 SbetaThal) had varying degrees of osteonecrosis of the hip. Four (36.4%) of the 11 SS patients with alpha-thal trait and 2 (16.7%) of those without alpha-thal trait had osteonecrosis. This difference is, however, not statistically significant (chi(2) = 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.

Frequency of the 677 C-->T mutation of the methylenetetrahydrofolate reductase gene among Kuwaiti sickle cell disease patients

Sickle cell disease (SCD) is relatively mild among Kuwaiti Arabs. However, an atypical subset of patients exists with frequent, severe vaso-occlusive crisis and osteonecrosis. The thermolabile variant of MTHFR, resulting from a C-->T mutation at nucleotide 677, has been shown to be associated with hyperhomocysteinemia, which is an important risk factor for premature vascular disease. We have screened an unselected group of 41 Kuwaiti SCD patients (33 SS and 8 Sbeta(0)-thal) attending the Hematology Clinic of Kuwait University Teaching Hospital for the MTHFR mutation, using a PCR-RFLP method. The patients were aged 2-41 years (mean of 12.8 +/- 8.6). One (2.4%) individual was homozygous for the mutation while 15 (36.6%) were heterozygous, giving an allele frequency of 20.7%. Twenty-one patients (14 SS and 7 Sbeta(0)-thal) were screened for osteonecrosis using MRI of the hip (spin-echo T1- and T2-weighted images). Seven (33.3%) had varying degrees of osteonecrosis, among whom the frequency of the 677 C-->T allele was 21.4%. The frequency was identical among those without osteonecrosis. Although the allele frequency is higher among our patients compared to American SS patients, our results do not suggest an association with osteonecrosis.

Influence of alpha-thalassemia trait on the prevalence and severity of anemia in pregnancy among women in Kuwait

Alpha-thalassemia is very common in the Kuwaiti population, but its influence on anemia of pregnancy has not been previously investigated. We have screened a group of 59 anemic (Hb < 11 g/dl) pregnant women for the alpha-thal-2 (-alpha-3.7 kb) deletion which is the commonest alpha-thal allele in this community, using a polymerase chain reaction method. A control group of 35 nonanemic (Hb > or = 11 g/dl) pregnant women was studied for comparison. All the women were in the second or third trimester of pregnancy. Among the 94 women in both groups, 69 (73.4%) had a normal complement of alpha-globin genes (alphaalpha/alphaalpha), 18 (19.1%) were heterozygotes (-alpha/alphaalpha) and 7 (7.4%) were homozygotes (-alpha/-alpha) giving an allele frequency of 17.0%. Among the anemic group, there were 44 (74.6%) individuals with a normal genotype, 9 (15.3%) heterozygotes and 6 (10.2%) homozygotes. In the nonanemic group, the corresponding prevalence figures were 25 (71.4%), 9 (25.7%) and 1 (2.9%), respectively. The difference between these distributions was statistically significant (chi2 = 37.5, p < 0.0001). However, the mean Hb values were similar in heterozygotes, homozygotes and normal individuals. We, therefore, conclude that while the alpha-thal trait affects the prevalence of anemia among pregnant Kuwaiti women, it does not affect its severity.

Th1 and Th2 cytokine profiles in sickle cell disease

We have investigated the levels of Th1 (IL-2 and IFN-gamma) 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 Sbeta-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-gamma 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-gamma 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.

Tumor necrosis factor-alpha is undetectable in the plasma of SS patients with elevated Hb F

Steady-state sickle cell disease (SCD) patients may have increased plasma levels of acute phase reactants and pro-inflammatory cytokines because of subclinical inflammation. We have estimated TNF-alpha levels in the plasma and in supernatants following peripheral blood mononuclear cell (PBMC) activation with phytohemagglutinin (PHA) in a group of Kuwaiti SCD patients using ELISA. The group consisted of 28 SS, 8 Sbeta-thal, and 2 SD patients all in steady state; 5 SS patients were studied during 7 episodes of painful crisis. The subjects were aged 2 to 16 years, with a mean of 7.3 +/- 3.5 years. The beta(S)-globin gene cluster haplotype, alpha-tha1 status, and spleen function were determined in the SS group using standard techniques. Most (82%) were homozygous for the Saudi Arabia/India haplotype and had elevated Hb F levels ranging from 15% to 35%. There were 24 controls (Hb AA or AS), of whom 14 were healthy and 10 were acutely ill at the time of the study. None of the children with SCD (either in steady state or crisis) had detectable plasma TNF-alpha, but four controls (3 acutely ill and one healthy) had levels ranging from 61.7 to 249.8 pg/mL. Following PHA stimulation most subjects responded with high levels of TNF-alpha, with the median level among the steady-state SS patients being significantly higher than that in the controls (both the acutely ill or healthy). It therefore appears that because of the mild disease among our Arab SS children, TNF-alpha is not detectable in their plasma in steady state; these children, however, had a significantly higher response than controls following PBMC activation.

GM-CSF in sickle cell anemia patients with elevated Hb F

We estimated plasma GM-CSF levels in a group of 28 steady-state sickle cell anemia (SS) patients in Kuwait, using an ELISA technique. There were 24 age-matched Hb AA controls, 14 of whom were healthy while 10 were acutely ill at the time of the study. Five SS patients were also studied during 6 episodes of painful crisis. Among the SS patients, 82.1% were homozygous for the Saudi Arabia/India (SAI) haplotype with Hb F ranging from 15 to 35% and total Hb from 8.5 to 11 g/dl. Three patients (siblings) were SAI/Benin compound heterozygotes with Hb F of 9-23% and total Hb >10 g/dl. One patient each was homozygous for the Benin or the Bantu haplotype; they had Hb F <2% and total Hb of 6.6 and 7.2 g/dl, respectively. Four (14. 3%) steady-state SS patients had detectable plasma GM-CSF ranging from 75 to 1,817.6 pg/ml. These included the 2 patients with Hb F <2. 0% and 2 with the SAI/Benin compound heterozygotes with Hb F of 11 and 9%, respectively. Four (66.7%) SS patients in crisis, 6 (42.9%) healthy controls and 6 (60%) acutely ill controls had detectable plasma GM-CSF. A clearcut association of GM-CSF with Hb F level or degree of anemia in steady-state SS patients could not be established. The appearance of GM-CSF in the plasma of patients in crisis and also among control subjects raises the possibility that other factors are involved in the production of this cytokine in the subjects studied.

A comparative study of perception of sickle cell anaemia by married Nigeria rural and urban women

Environmental factors may influence perception of or attitude to chronic disorders. The perception of sickle cell anaemia (SCA by 165 married Nigerian rural and 507 urban women was studied to determine how living in an urban or rural environment may influence perception. None of the subjects had children with SCA. The instrument used for data collection was a structured questionnaire designed to enquire into their knowledge about the cause, precipitating factors for crises, clinical features of SCA and their opinions regarding traditional and modern treatment options for the disorder. As a group, urban women had better knowledge about SCA than rural women probably because their social environment afforded a wider scope for interaction with and information exchange among people. For most respondents, the educational institutions attended the health institutions in the locality and the electronic media were poor sources of information on SCA. The study showed a serious lack of information about important aspects of SCA among rural women. We think the training of primary health care providers as counsellors on SCA, the inclusion of instruction about SCA in the curriculum of schools and sustained outreach programmes on SCA on the electronic media would ensure early education of people in both rural and urban communities and help to improve perception of the disorder.

Influence of alpha-thalassemia on cholelithiasis in SS patients with elevated Hb F

Chronic hemolysis, with consequent hyperbilirubinemia, predisposes SS patients to pigment gallstones. The other factors which influence the development of stones in these patients have not been identified. We have carried out a combined prospective and retrospective study of SS patients in Kuwait and specifically investigated the influence of coexistent alpha-thal trait on the prevalence of gallstones. A total of 45 patients (30 males, 15 females) with ages ranging from 1 to 16 years (mean 7.2 +/- 3.1) were studied. Most were either homozygotes for the Saudi Arabia/India haplotype (86.7%) or compound heterozygotes for this and the Benin haplotype (11.1%). They were screened for gallstones with ultrasonography. alpha-Globin genotypes were determined using a combination of PCR and allele-specific oligonucleotide hybridization techniques to identify the common alpha-thalassemia alleles in this population. Gallstones were detected in 7 (15.6%) patients (4 males, 3 females), whose mean age (10.5 +/- 5.5 years) was significantly higher than that (6.8 +/- 3.2 years) of those without stones (p < 0.01). The mean total Hb of the former (8.4 +/- 0.8 g/dl) was also significantly (p < 0.05) lower than in the latter (9.5 +/- 1.3 g/dl), while the difference in mean Hb F levels was not significant. None of the 4 alpha-thal homozygotes had gallstones while 2 of 13 heterozygotes and 5 of the 23 patients without coexistent alpha-thal had. The differences in these proportions are statistically significant (chi2 = 20.4, p < 0. 001). It therefore appears that coexistent alpha-thal decreases the chance of developing gallstones in Arab SS patients. This may be related to less hemolysis in such patients as shown by their higher mean Hb level.

Alpha-, beta-, and gamma-mRNA levels in beta-thalassemia; transcriptional and translational differences in heterozygotes, homozygotes, and compound heterozygotes

We have determined the relative levels of alpha-, beta-, and gamma- (G gamma- and A gamma-) mRNAs in the reticulocytes of patients with mild beta-thalassemia intermedia due to combinations of promoter mutations and a classical type of beta-thalassemia, as well as in their relatives. The expected differences in the alpha/beta-mRNA ratio confirmed the mild suppression of beta-mRNA synthesis, particularly in heterozygotes for the -101 (C-->T) promoter mutation and the large increase in the relative gamma-mRNA level in compound heterozygotes. A significant discrepancy between Hb F and gamma-mRNA levels, observed in previously published studies, was confirmed indicating a less efficient gamma-mRNA translation. When the two different gamma-mRNA (G gamma- and A gamma-) levels were determined it was observed that in beta-thalassemia heterozygotes the extra gamma-mRNA was primarily of the G gamma type suggesting a more efficient translation of the A gamma-mRNA. This difference disappeared in homozygotes and compound heterozygotes: both mRNAs (G gamma- and A gamma-) translate with an equal efficiency.