Sickling Test Research Articles

Two Case reports on Sickle Cell Disease: Presented with Pallor and recurrent Attacks of Bones and Joints Pain

Sickle cell disease is a hereditary hemolytic anaemia due to abnormal haemoglobin. Sickling of RBCs occurs due to abnormal hemoglobin which leads to vaso-occlusive crisis. The highest frequency of sickle cell disease is found in tropical regions, particularly in Sub-Saharan Africa, tribal regions of India and in Middle-East. Though sickle cell disease is not common in our country, recently we have two cases of sickle cell disease presented with fatigue and pallor with bones and joints pains. These cases were diagnosed by electrophoresis of hemoglobin, peripheral smear, Sickling test and relevant investigations. The most significant advance in the therapy of sickle cell anaemia is the introduction of Hydroxyurea to prevent acute chest syndrome, number of pain crisis, repeated transfusions and number of trips to hospital. Hydroxyurea is considered in first case (case no. 1) as he has frequent episodes of acute attack and recover well after blood transfusion. Case no.2 also a good candidate for Hydroxyurea but not given as his acute attack is less frequent and in close contact for further observation and evaluation.Medicine Today 2017 Vol.29(2): 51-54

The Assessment and Sustainable Management of Sickle Cell Disease in the Indigenous Tharu Population of Nepal

Sickle cell disease is an inherited hemoglobinopathy associated with significant morbidity and mortality. Reports suggest a high sickle cell disease burden among the indigenous Tharu population of Nepal, who for centuries have inhabited regions where malaria is endemic. Unfortunately, health care resources are limited and often inaccessible for Tharu individuals suffering from sickle cell disease. We conducted a large-scale screening effort to estimate the prevalence of Hb S (HBB: c.20A>T) among the Tharu population and delivered community-based education sessions to increase sickle cell disease awareness. A total of 2899 Tharu individuals aged 6 months to 40 years in the rural district of Dang in Western Nepal were screened using a sickling test, of whom, 271 [9.3%; 95% confidence interval (95% CI): 8.3–10.4%] screened positive for Hb S. Those who screened positive were offered diagnostic gel electrophoresis testing. Of the 133 individuals who underwent diagnostic testing, 75.9% (n = 101) were confirmed to be Hb AS heterozygotes, 4.5% (n = 6) were confirmed to be Hb SS homozygotes and 19.5% (n = 26) were false positives. These findings support a large burden of sickle cell disease among the Tharu population and highlight the importance of appropriate resource allocation and management. With a positive predictive value of 80.0% (95% CI: 73.0-87.0%), the sickling test in conjunction with raising local sickle cell disease awareness may be a simple and sustainable way to promote access to health resources.

Detection of Hemoglobin D in Tharu Community of Banke, Nepal

Background: Patients presenting with microcytic anemia, hepatosplenomegaly, abnormal hemoglobin level in electrophoresis and negative sickling test should have high suspicion for HbD disease. This occurrence is more in certain communities. While investigating the etiopathogenesis of subjects with microcytic anemia (n=30), we came across 3 patients with HbD disease.Aim: Present study describes the clinical and hematological findings of 3 patients.Material and Methods: This was an observational study conducted between August, 2014 to July, 2015 in Department of Pathology of Nepalgunj Medical College. Of 30 patients diagnosed as microcytic anemia, 3 patients were selected.Results : The patients belonged to Tharu Chaudhary community of Banke district of Nepal. Age of the patients ranged from 8 to 13 years. All the patients had generalized pallor. Two of 3 patients had fever, joint pains and jaundice. One of the patients had hepatosplenomegaly. Total hemoglobin ranged from 7.1 to 8.4 gm/dl. Patients had microcytic anemia. Sickling test was negative in all the 3 patients. Hemoglobin (Hb) electrophoresis revealed peaks in HbS region. Due to negativity of sickling test, the abnormal hemoglobin peak was interpreted as HbD. Thus, 2 patients had homozygous HbD disease while another patient had heterozygous HbD trait.JNGMC Vol. 14 No. 1 July 2016

Traveling to Angola to Validate a Paper-Based Sickle Cell Disease Test.

When I started graduate school, I had no idea that it would take me halfway around the world to a small clinic in Cabinda, Angola, but I'm glad that it did. Since 2011, I have been a part of the team of engineers and clinicians, led by Dr. Sergey Shevkoplyas, working to develop a simple, low-cost, paper-based test for sickle cell disease-a common inherited blood disorder that is most prevalent in sub-Saharan Africa (Figure S1).

Lower Transcranial Doppler Flow Velocities in Sickle Cell Anemia Patients on Hydroxyurea: Myth or Fact.

Transcranial Doppler (TCD) detects stroke risk in patients with sickle cell anemia (SCA). Hydroxyurea therapy has the ability to induce increased levels of fetal hemoglobin in sickle cells thus decreasing tendency for red cell sickling. This study aimed to evaluate TCD findings in SCA patients on hydroxyurea and correlate the time-averaged mean velocity (TAMV) with their hematological parameters. Forty SCA patients of both sexes, aged 16-22years with no history of stroke were screened with TCD for an elevated TAMV, divided into: Group T (20 patients on blood transfusion); and Group H (20 patients on daily hydroxyurea). For all, full medical history, clinical examination, hemoglobin, hematocrit, leukocytes, platelets, fetal hemoglobin and sickling test, in addition TCD to describe the pattern of cerebral blood flow abnormalities were done. TAMV in all cerebral arteries were significantly higher in Group T than Group H, the highest TAMV (147.5±57.09cm/s) was found in the right middle cerebral artery and correlated negatively with hematocrit in Groups H (P<0.001). There were 2 (10%) abnormal TAMV results and 5 (25%) conditional in Group T, while all results were normal in Group H. Hydroxyurea therapy may lower TCD velocities and prevent the risk of primary stroke in SCA patients.

Evaluation of Antenatal Care Screening According to the National Recommendations in Senegal

In the fight against maternal and infant mortality, Senegal has defined screening tests guidelines for antenatal care. A minimal list of six (6) tests should be requested during the first ANC visit. To contribute to the reduction of maternal mortality in Senegal, we conducted a study to evaluate, this practice in health facilities, taking into account the national guidelines in order to formulate recommendations. The study was conducted in 16 health peripheral facilities. We collected data on tests requested, pregnant age, pregnancy age, gestity, midwives monthly salary, midwives number, type of structure (Hospital and Health Center), regions (capital and others), and the availability of guidelines. The quantitative data were collected from 1692 pregnant women, 61 midwives and 16 financial managers with appropriate tools, from February 2013 to July 2014. Data were entered in Microsoft Excel versions 2013 and Open Clinica and then exploited and analyzed in SPSS version 20. Univariate and bivariate analyses were computed. Only 49.2% of pregnant women have received the 6 recommended tests. Requested tests were Syphilis (96%), Blood group (90%), Emmel Test for sickle cell anemia (90%), Hemogram (81%), HIV serology (78%) and Protein urine test (67%). Factors associated with guidelines adherence were: (i) first antenatal visit (p <0.001), (ii) midwives monthly salary (R=-0,232), and (iii) regions type (p<0.001). It is important to take into account these results. For a better antenatal care, we recommend to train and motivate midwives on the national guidelines, in Senegal, and to sensitize childbearing about the importance of tests.

Development of a Novel, Portable Cost-Effective Sickle Cell Disease Diagnostic Test Suitable for Neonatal Screening in Low Resource Countries

Background: Sickle cell disease (SCD) is common throughout sub-Saharan Africa, where 75% of the 300,000 global births of affected children live. A significant proportion of these children die before adulthood, with preventable conditions such as pneumococcal infection. Introduction of neonatal screening in the developed world has cut down the mortality rate for SCD from 16% to >1% by allowing targeted interventions. A low-cost, rapid and point-of-care diagnostic test is needed to improve the feasibility of neonatal SCD screening in developing countries due to limited economic constraints. Lateral flow-immunoassay (LFIA) devices offer an attractive approach to develop such a test. LFIA tests are widely used for the diagnosis of infectious and non-infectious diseases in developing countries and offer advantages of stability, precise performance, interpretation by minimally trained users without requiring refrigeration during shipping and storage.Methods: The conventional antibody (ab) based diagnostic approach to SCD is to utilize antibodies specific to the mutated hemoglobin (Hb), but such a strategy requires multiple antibodies, each specific to a given mutated form. To design a simple, cost-effective diagnostic, an alternative strategy of utilizing a single anti-human HBB ab that does not recognize any mutated form was adopted. In this device, a positive line would denote normal adult Hb and an absence of a positive line would denote a diagnosis of SCD. A number of monoclonal anti-human HBB abs were initially screened in direct enzyme-linked immunoassays (ELISA) using different purified hemoglobins (HbA0, HbS and HbA2) as antigens to identify candidates to develop the LFIA device. Based on the results from direct ELISAs, appropriate capture and detection ab pairs were generated to develop sandwich ELISA, which can be translated to a sandwich LFIA format. Results of ELISAs using pure Hbs were confirmed by using diluted peripheral blood samples from healthy and SCD patients. Strip-based LFIA was designed with 4 antibodies A) a device control using anti-mouse ab that confirms appropriate lateral flow B) a Hb control ab that recognizes all forms of HBB to confirm the presence of enough adult Hb in the sample, C) an HBB ab that only recognizes HbA0 but not HbS and HbA2 and D) a gold conjugated alpha chain specific ab as a labelled recognition element. The incorporation of gold nanoparticles as labels allows visual examination of colors at the test and control lines, resulting in qualitative or semi-quantitative analysis.Results: The results from the direct ELISA screening identified two potential antibodies that can be used in the LFIA, SCAD001 and SCAD003. SCAD001 was the most differentiating with a 10-fold difference between HbA0 vs. HbA2 or HbS, which allows its use as a test line. The optical density (OD) reading for SCAD001 with HbA0 HbA2 and HbS were 0.867, 0.07 and 0.08, respectively (Figure 1a). SCAD003 was able to bind all three variants of Hb with high OD readings of 3.7, 3.6, and 3.7, respectively, suggesting its potential to be used as a gold conjugation ab. In the sandwich ELISA format, SCAD001 demonstrated excellent selectivity for HBA0 over other variants of Hb (1.4 vs .04 for HbA0 and HbS, respectively). A pilot LFIA test device was then designed using SCAD001. Representative results as shown in Figure 2 from an LFIA test using SCAD001 demonstrate that the positive line is evident with HbA0 but not with HbA2 and HbS. These devices are currently being scaled up to be evaluated in different test conditions. Results from the current experiments using peripheral blood samples from patients with different forms of SCD and a comparison of current standard of care diagnostic vs LFIA device will be included in the presentation.Conclusion: These results demonstrate the feasibility of a novel approach of designing an LFIA device based on anti-HBB ab that selectively identifies normal Hb but not other variants. With its simple design and a single differentiating ab this device has the potential to be further developed as a neonatal screening test in low resource countries. [Display omitted] [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Prevalence of Sickle Cell Trait in the Southern Suburb of Beirut, Lebanon.

ObjectiveThe objective of this study was to assess the prevalence, gender differences, and time trends of Sickle Cell Trait in the Southern Suburb of Beirut, Lebanon, as well as to highlight the importance of screening for Sickle Cell Trait carriers in this population. Another objective was to describe a new screening technique for Sickle Cell Trait carriers.MethodsThis was a retrospective cohort study carried out at a private laboratory in the Southern Suburb of Beirut, Lebanon between 2002 and 2014. The sickling test was carried out for each patient using two methods: the classical “sodium metabisulfite sickling test”, and the new “sickling test method” used in the private lab. As a confirmatory test, hemoglobin electrophoresis was run on a random sample of 223 cases which were found to be positive using the two sickling tests.ResultsA total of 899 cases were found to be positive for the sickle cell trait out of 184,105 subjects screened during the 12-year period, prevalence = 0.49% (95% CI: 0.46 – 0.52). Among the total sample, females were found to have higher prevalence, where no time trend over the studied period was noted. The haemoglobin electrophoresis method confirmed the results of this new sickling test technique among the random sample of the 223 cases.ConclusionWe found that the prevalence of sickle cell trait is lower as compared to other Arab countries, higher in females, with no significant time trend. The sickle cell test was found to be an accurate, simple and cheap test that could be easily added as a requirement for the pre-marital testing to screen for Sickle Cell Trait carriers.

Sickle solubility test to screen for sickle cell trait: what's the harm?

Sickle solubility test to screen for sickle cell trait: what's the harm?

Sickle solubility test to screen for sickle cell trait: what's the harm?

Sickle solubility test to screen for sickle cell trait: what's the harm?

Validation of a novel point of care testing device for sickle cell disease.

BackgroundSickle cell disease is one of the most common inherited blood disorders. Universal screening and early intervention have significantly helped to reduce childhood mortality in high-resource countries. However, persons living in low-resource settings are often not diagnosed until late childhood when they present with clinical symptoms. In addition, confirmation of disease in affected individuals in the urgent care setting is limited in both high- and low-resource areas, often leading to delay in treatment. All of the current diagnostic methods rely on advanced laboratory systems and are often prohibitively expensive and time-consuming in low-resource settings. To address this need, the Sickle SCAN™ test has been developed to diagnose sickle cell disease and sickle cell trait at the point of care without electricity or advanced equipment.MethodsThis study was conducted to evaluate and validate the diagnostic accuracy of the Sickle SCAN™ test, a novel point of care test for sickle cell disease. Thus, we describe the laboratory testing and clinical validation of the Sickle SCAN™ test in individuals >1 year of age using capillary blood. The Sickle SCAN™ test was created using advanced, qualitative lateral flow technology using capillary blood to identify the presence of hemoglobin A, S, and C allowing for detection of results with the naked eye.ResultsLaboratory testing using venous blood demonstrated 99 % sensitivity and 99 % specificity for the diagnosis of HbSS, HbAS, HbSC, HbAC, and HbAA. Seventy-one subjects underwent capillary blood sampling at the point of care for further validation. This test detected the correct A, S, and C presence with an overall diagnostic accuracy of 99 % at the bedside.ConclusionThe Sickle SCAN™ test has the potential to significantly impact the diagnosis and treatment for sickle cell disease worldwide as well as enhance genetic counseling at the point of care. Further validation testing will be conducted in newborns in resource-poor settings in upcoming studies.Electronic supplementary materialThe online version of this article (doi:10.1186/s12916-015-0473-6) contains supplementary material, which is available to authorized users.

Haemoglobin Electrophoretic Patterns, ABO and Rhesus D Blood Groups Distribution among Antenatal Women in Sokoto, Nigeria

Background: This study was carried out to determine the haemoglobin electrophoretic patterns and distribution of ABO and Rhesus D blood group among antenatal women attending Usmanu Danfodiyo University Teaching Hospital (UDUTH), Sokoto. Method: Three hundred consecutively-recruited and consenting pregnant women aged 18 – 45 years (mean age 27.62 ± 3.6 years) constituted the subjects for this study. Standard method involving cellulose acetate electrophoresis was carried out using Tris EDTA borate at alkaline pH of 8.6. Hemoglobin S was confirmed using sickling test involving sodium metabisulphite. Standard tile method using potent antisera was used for the determination of ABO and Rhesus D blood group. Results: Among the 300 pregnant women studied, 221 (73.7%) were HbAA, 67 (22.3%) were HbAS, 11 (3.7%) were HbAC and 1 (0.3 %) was HbSC (p=0.01). HbAA was more prevalent among group O subjects followed by A, B and AB. HbAS was more prevalent among group A followed by B, O and AB. HbAC was more prevalent among group A and O followed by B and AB. The prevalence of HbSC was concentrated among blood group O subjects. There was no homozygous S and C haemoglobinopathies. The ABO blood group distribution indicated that blood group O was the predominant blood group followed by group A, B and AB (p=0.01). The ABO distribution among the subjects followed the pattern O>A>B>AB. A significant number of subjects were Rhesus D positive (94%) compared to 6% who were Rhesus D negative (p=0.001). Conclusion: This study indicates that haemoglobinopathies is prevalent among pregnant women in Sokoto, North Western Nigeria. The results from this study also show that blood group O is the predominant ABO blood. Evidenced based data obtained from this study will facilitate optimum stocking of blood and blood products in blood banks in the area and the management of Haemolytic Transfusion Reaction and Haemolytic Disease of the Foetus and Newborn.

Diagnosis of a novel hemoglobinopathy of compound heterozygosity of hemoglobin S/hemoglobin Q India

BackgroundA novel double heterozygosity for the α chain variant Hb Q India and β chain variant Hb S is described. Hb S is prevalent in the central part of India while Hb Q India in its heterozygous state is found mainly in Sindhi families. MethodsIdentification of both the variants, Hb S and Hb Q India, was done based on chromatograms of HPLC and capillary zone electrophoresis (CE). Confirmation of variants was done by PCR based amplification refractory mutation system (ARMS) technique. ResultsBoth HPLC and CE confirmed the presence of Hb S. HPLC showed a pointed narrow peak of Hb Q India at retention time of 4.55min while it is eluted in Hb D zone on CE. A hybrid variant of these α and β globin chains was eluted in Hb C window and Hb C zone on HPLC and CE respectively. Molecular studies using ARMS technique confirmed these findings. Both the cases showed positive sickling test and presented with mild anemia. ConclusionThis is a unique 2 index cases for compound heterozygosity of Hb S with Hb Q India.

Frequency distribution of sickle cell anemia, sickle cell trait and sickle/beta-thalassemia among anemic patients in Saudi Arabia

Background:Notwithstanding, the growing incidence of sickle cell hemoglobinopathies (SCH) such as sickle cell anemia (SCA) or sickle cell disease, sickle/beta-thalassemia; the exact prevalence remains obscure in Saudi Arabia. Hence, this study is an attempt to determine the frequency of SCA and sickle cell trait (SCT) among all anemic patients with SCH treated at the King Abdul-Aziz Medical City (KAMC), Riyadh, Saudi Arabia. Furthermore, the hemoglobin (Hb) S and other Hb patterns (Hb AS and Hb F) were also estimated in SCA and SCT patients.Materials and Methods:Results of Hb capillary electrophoresis performed on all patients with SCH from January 2011 to December 2013 were evaluated retrospectively.Results:Of a total of 3332 patient data analyzed, 307 were anemic patients (58% males and 42% females) with SCH. The sickling test showed all the patients to be positive. Hb electrophoresis revealed the incidence of 96.7%, 3.3%, and 0% of the patients suffered from SCA, SCT and sickle/beta-thalassemia, respectively. Patients with SCA had a higher level of Hb F and showed no crisis when compared with other SCA patients who had lower or no Hb F levels.Conclusion:SCA is relatively frequent among males (56.4%) than females out of all patients with SCH. The SCA incidence was more common (48.5%) among children, frequency of SCT among adult age group was 1.6%, while sickle/beta-thalassemia was 0%.

Divergence from Hardy Weinberg Equilibrium in Newborn Screening Cohorts for Sickle Hemoglobin

Newborn screening (NBS) for hemoglobinopathies was first introduced in the 1970’s to prevent infectious complications of homozygous sickle cell disease (hemoglobin [Hb] SS). The frequency of HbSS in newborns can be estimated using carrier rates (heterogygotes), assuming Hardy Weinberg Equilibrium (HWE). The current study examined whether NBS cohorts matched expected HWE distribution, and possible reasons for divergence. For the purpose of this study, all variants other than HbS were considered to be HbA. A total of 82 studies (1956 to 2013) were retrieved, of which 7 were excluded (carrier parents selected or screening sickle test used). Distribution of Hb SS, AS and AA was examined in 75 studies, from the following regions: Sub Saharan Africa n=26, Brazil n=12, USA n=12, EU n=10; Middle East/North Africa n=7, Caribbean n=6, India n=1, Canada n=1. The following screening laboratory methods were used: cellulose acetate electrophoresis (n=22), isoelectric focusing (n=21), high performance liquid chromatography (n=16), filter paper or micro column (n=7), other (n=9). A total of16,377,450 newborns or infants were included. In mixed random models, relative risk (RR) of detecting HbSS compared to expected HWE distribution was 2.06 (95% confidence interval [CI] 1.86, 3.66), p<0.001. In cohorts where HbAS carrier rates was >= 15%, RR was 1.44 (95% CI 1.23, 1.70), p=0.005; if carrier rates were between >=5% and <15%, RR was 1.62 (95% CI 1.20, 2.19), p=0.004; if carrier rates were <5%, RR was 5.74 (95% CI 3.4, 9.78), p<0.001. Thirteen studies provided data by subgroup: place of origin, ethnicity or race. Affected individuals were more likely to cluster in studies with lower HbS gene frequency (figure 1). Conversely, HbSS RR observed compared to expected HWE distribution was highest in populations with lowest overall gene frequency (figure 2). Overall RR for detecting HbAS compared to expected was 0.96 (95% CI 95, 97) p<0.001. Controlling for gene frequency, the Caribbean region was least likely to deviate from the expected HWE distribution, compared to other regions (RR 1.05, 95% CI 1.01, 1.05, P=0.007); cellulose acetate electrophoresis based methods were most likely to deviate from expected HWE distribution, compared to other methods (RR 0.97, 95%CI 0.95, 0.100, p=0.038). Deviation from HWE is commonly observed in NBS cohorts. It is an expected finding when smaller populations (e.g.migration) carrying a gene, exist within a larger population less affected with the same gene. However, even when controlling for gene frequency, regional variations were noted. Reasons may include further variations in population homogeneity, non-random mating within smaller groups (consanguinity), variations in hemoglobin variant distribution (alpha, beta thalassemia, fetal hemoglobin expression). Lab methods may also affect agreement with HWE distribution, as correct classification of non-affected individuals may vary between methods (normal homozygotes, variants and carriers). Divergence from HWE, especially when observed HbSS occurrence is less than expected, or when population Hb S gene distribution is known, may serve as a rapid and inexpensive quality control measure. Further examination of possible reasons for HWE deviation and caution when estimating burden of disease using carrier rates derived from NBS cohorts appear warranted. [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Screening for sickle-cell trait at accession to the United States military.

Condition Definition SCT is a heterozygotic carrier state in which an individual has one copy of the normal HbA gene and one copy of the HbS variant. Commercial tests for SCT have been available since the early 1970s. The sickle solubility test qualitatively detects the presence of HbS by precipitating sickle hemoglobin in the presence of an oxygen depleting reagent. With a sensitivity approaching 99% and a specificity of 100%, sickle solubility provides an accurate screening method. The hemoglobin electrophoresis test is a confirmatory test that quantifies the percentage of HbS and is therefore able to distinguish among the HbS disorders, such as SCT or sicklecell disease. According to the 59th Clinical Lab Flight at Joint Base San Antonio-Lackland, Texas (oral communication, November 2013), the U.S. Air Force (USAF) spends $4.86 on the sickle solubility test and $9.41 on the hemoglobin electrophoresis test.

Priapism Associated with Homozygous Hb E State: A Causal Association or an Incidental Finding?

Dear editor, Priapism, that is, persistent penile erection that continues hours beyond, or is unrelated to, sexual stimulation, is a relatively uncommon disorder and is a medical emergency. Typically, only the corpora cavernosa are affected [1]. The term priapism was derived from the Greek god Priapus, son of Aphrodite who was born with oversized genitals [2]. The haematological causes for priapism include Sickle cell anaemia, Leukaemia, Multiple myeloma, Paroxysmal nocturnal haemoglobinuria, Thalassaemia, Thrombocythemia and Henoch–Schonlein purpura [3]. As far as hemoglobinopathies are concerned, priapism is most often encountered in sickle cell disease in 38–42 % of cases followed by sickle/beta thalassemia [4, 5]. Priapism is also noted in patients with sickle cell trait even though the incidence is low as compared with sickle cell anaemia [6–9]. However, so far priapism in Hb E homozygosity is not reported in literature. In this correspondence we intend to bring to notice an unusual association of priapism with Hb E homozygosity. A 27 years old male, resident of North Eastern part of India was referred to our haematology OPD to rule out any underlying haematological disorder as the individual had an episode of priapism 3 months ago. The patient had an episode of unprovoked painful persistent erection for more than 8 h for which he sought medical advice. The surgeon at that medical center had managed with therapeutic needle aspiration from corpora cavernosa combined with flushing of cavernosa with normal saline to clear the sludged blood. The patient’s symptom subsided subsequently with the intervention and was referred to our center for further evaluation. On detailed clinical history, the individual was not on any medication for chronic illnesses; neither was he abusing any psychoactive drugs, alcohol, no history of prior trauma to the perineal region. His physical examination revealed mild pallor. There was no hepatosplenomegaly or lymphadenopathy. Systemic examination did not reveal any abnormality. On USG abdomen, spleen was not reported as enlarged (Span 13 cms). On investigations, haemoglobin, total leucocyte count and platelet count were 9.1 gm/dL, 7.1 9 10/lL and 118 9 10/lL respectively. Peripheral smear examination revealed microcytic hypochromic red cells and target cells with normal differential leucocyte count and reticulocyte count of one percent. There were no sickle cells or atypical cells in peripheral smear and sickling test was also negative. Subsequently Hb HPLC was performed which revealed with Hb A2 ? E of 92.6 % (Retention time3.68 min), Hb A of 6 % (Retention time 2.29 min) and Hb F (Retention time 1.06 min) of 1.6 % (Fig. 1; Table 1). This was followed by parental study which revealed Hb A2 ? E in mother and father of 29 and 27 % respectively suggestive of both parents being heterozygous for Hb E, S. Venkatesan A. Purohit (&) M. Aggarwal P. K. Singh T. Seth H. P. Pati Department of Hematology, All India Institute of Medical Sciences, New Delhi, India e-mail: purohitabhi80@gmail.com

Incidence of Human Immunodeficiency Virus in Sickle Cell Patients in the Cape Coast Metropolis, Ghana

Context: Human immunodeficiency virus (HIV) is a well-known pathogen that causes acquired immunodeficiency syndrome (AIDS). The course of HIV infection and progression may be influenced by sickle cell traits. Objectives: The aim of this study was to determine the incidence of HIV among sickle cell patients in the Cape Coast metropolis. Methods: A cross sectional study was conducted among patients who visited the Central Regional Hospital, Cape Coast. About 2 ml of blood sample was drawn from each participant for sickle cell test using sodium metabisulphite solution. Sickle cell positive samples were selected and tested for the presence of HIV using Alere DetermineTM HIV-1/2. Results: A total of 75 patients made up of 25 males and 50 females were enrolled. Their age ranges between 4 to 59 years (27, 1 - 15 years; 24, 16 - 30 years; 17, 31 - 45 years; 7, 46 - 60 years). Fifteen (15) (20%) had received at least a single blood transfusion while the remaining 60 (80%) had never received blood transfusion before the study. Thirty-six patients (48.0%) were married and the other 39 patients (52.0%) were single. Five patients (6.7%) had antibodies to HIV whereas 70 patients (93.3%) were not with the virus. Conclusion: The incidence rate of HIV among sickle cell trait children and the youths of Cape Coast metropolis were found to be 6.7%. This may suggest that sickle cell traits in children and the youth may be associated with HIV transmission.

Screening of Thalassaemia Carriers and Its Limitations

The α and β-thalassaemias (thal) are common genetic disorders of globin chain synthesis where the carriers have deficiency of α or β globin chain respectively. In resource limited settings, the naked eye single tube red cell osmotic fragility (NESTROFT) has been used for screening of thalassaemia. It has low specificity compared with its sensitivity. Screening of carriers encompasses automated/semi-automated techniques and manual methods for presumptive diagnosis of thalassaemia. The current strategy in screening involves a step by step process simplified into the following acronym, BHES. B, refers to blood counts and a film; H, haemoglobin (Hb) subtyping; E, Hb electrophoresis; and S, stability (H-inclusion and Sickle cell test). Blood counts and red blood cell indices are now available by automated instrumentation where a cut-off value of mean corpuscular Hb (MCH)<27 pg necessitates further investigation for thalassaemia or iron deficiency. The distribution of normal Hb subtypes (HbA, HbA2 and HbF) is done commonly by high performance liquid chromatography (HPLC) or capillary zone electrophoresis (CZE). The thalassaemia trait phenotype is indicated by a near normal Hb, microcytic and hypochromic red cell indices. In classical β-thalassaemia trait, the cut-off value of HbA2 value is 4% and above. However, milder mutations can result in HbA2 values between 3.2 to 3.9%. In alpha thalassaemia trait the HbA2 falls within the normal range. In a carrier of α0-thalassaemia, occasional or few H-inclusions suggests its presence. However, absence of H-inclusions does not rule out its presence. Recently, it has been shown that the current screening method of thalassaemia carriers has its limitations. Mild mutations may show normal or near normal red cell indices and be missed in the screening process. Carriers with these mutations can cause thalassaemia intermedia. In addition there are mutations that have more profound effects resulting in more severe outcome but have carriers with normal red cell indices. In α-thalassaemia intermedia, HbH disease, those with nondeletional mutations are clinically more severe. These non-deletion mutations include Hb Constant Spring, Hb Pakse and Hb Adana. Carriers with these non-deletional α-thal mutations have normal red cell indices. Cases of hydrops foetalis have been reported with a homozygous state of Hb Adana and also in α0 with Hb Adana. Coinheritance of α or β-thal also effects the red cell indices making them near normal. Thalassaemia intermedia and major have serious implications and prevention requires strategies to detect couples at risk. Mutational spectrum of the globin genes is updated continuously with improved diagnostic technology. Clinical programs preventing thalassaemia are presently based upon prospective screening and prenatal diagnosis. In order for prevention to be effective, there is a need to be aware that mutations can exist in thalassaemia carriers where the red cell indices are normal.

Sickle Cell Solubility Test: Evaluation of an In-House Method

This study aims to assess the performance of an in-house sickle cell solubility test (SCT) and compare it against data published on other in-house and commercial methods. Also assessed are the effects of possible interference due to haemoglobin (Hb) level, Hb F and Hb S levels, as well as lipaemia, icterus and haemolysis index. A total of 1030 patient samples were tested by the SCT and subsequently confirmed by high-performance liquid chromatography (HPLC). Seventy-five (7.3%) samples revealed a positive SCT whereas 955 (92.7%) were negative. The sensitivity and specificity of the method was 100% and it was shown to detect low levels of Hb S (12.1%). These data show that the authors’ in-house SCT method has an excellent performance against other documented methods (including some commercial kits), which is probably explained by its robustness against low levels of Hb S and interfering substances such as lipaemia. The authors believe this shows that in-house tests are able to produce highly reliable results comparable to, if not better than, certain commercially available CE-marked kits.