Splenic Subcapsular Hematoma from Commercial Air Travel: Case Report of a Unique Incident of Altitude-Associated Splenic Syndrome.

BACKGROUND: Sickle cell trait (SCT), the heterozygous form of sickle cell disease, is generally thought of as a benign condition. However, it is possible for those with SCT to have serious complications, especially when they are exposed to high altitudes where oxygen levels are low. CASE REPORT: We present a case of a 41-year-old man with a history of SCT who developed severe epigastric pain and nearly lost consciousness while traveling on a commercial airplane. His twin brother, who also has SCT, had a similar episode in the past and required a splenectomy. A splenic subcapsular hematoma was found in a computed tomography scan of the abdomen and pelvis with intravenous contrast. He was admitted and managed conservatively until his symptoms resolved. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Though SCT is prevalent in our population, the complications that can arise, such as altitude-associated splenic syndrome, have likely not been thoroughly investigated. Physicians should add this condition to their differential if they practice at locations near airports or in areas of higher altitude and if their patients have a past medical history of SCT.

Early-onset indicators of a hypercoagulable state and clinical complications in a cohort of children with sickle cell trait.

Adults with sickle cell trait (SCT) have a procoagulant state with increased risk of thromboembolism, but limited data are available for children. We compared the coagulation profile of children with SCT, different sickle cell disease (SCD) genotypes, and healthy controls. Compared to controls and similarly to HbSC patients, 41 SCT children (mean age 6.85 years; 20 males; 88% Africans) had a characteristic procoagulant profile: higher levels of factor VIII, von Willebrand factor (VWF) Ag and CBA, D-dimer; lower levels of ADAMTS 13 activity, ADAMTS13 activity: VWFAg, plasminogen activator inhibitor, tissue plasminogen activator. Moreover, 13/41 had clinical complications of SCD, five requiring hospitalization.

Protocol for a comparative cross-sectional study on characterisation of auditory impairment in sickle cell disease and sickle cell trait and its impact on health-related quality of life in Nigeria.

INTRODUCTION: Sickle cell disease (SCD) and sickle cell traits (SCT) are genetically inherited red blood cell disorders common among people of African descent. Nigeria has a high prevalence of SCD, with a prevalence of 2.28%-3% and SCT, 25%-30%. Poorly managed SCD and SCT can lead to sensorineural hearing loss and health-related quality of life (HRQoL) issues. This research aims to assess these possible complications of SCD and SCT in Nigeria. METHODS AND ANALYSIS: The study will use a comparative cross-sectional design at study power 80% to investigate the association between SCD/SCT, hearing impairment and HRQoL. Participants will be divided into two groups: a cohort and a control group. Hearing levels will be assessed through audiometric assessments and categorised by type and severity of hearing impairments using WHO classifications. HRQoL will also be assessed using WHO Disability Assessment Schedule 2.0. Statistical analyses will be performed using the SAS V.9.4, with parametric or non-parametric analysis depending on the distribution. Relationship between key variables will be determined via correlational tests, χ2, Fisher's exact test and multivariable logistic regression analyses. ETHICS AND DISSEMINATION: The proposal has been fully reviewed and registered by the University of Cape Town's Faculty of Health Sciences Human Research Ethics Committee (HREC REF 228/2022) and the University of Abuja Teaching Hospital Human Research Ethics Committee (HREC/PR/2020/08/007). Information dissemination will be through conferences, peer-review publication and personal communications. The Strengthening the Reporting of Observational Studies in Epidemiology statement will be followed in writing the manuscript.

Sickle cell allele HBB-rs334(T) is associated with decreased risk of childhood Burkitt lymphoma in East Africa.

Burkitt lymphoma (BL) is an aggressive B-cell lymphoma that significantly contributes to childhood cancer burden in sub-Saharan Africa. Plasmodium falciparum, which causes malaria, is geographically associated with BL, but the evidence remains insufficient for causal inference. Inference could be strengthened by demonstrating that mendelian genes known to protect against malaria-such as the sickle cell trait variant, HBB-rs334(T)-also protect against BL. We investigated this hypothesis among 800 BL cases and 3845 controls in four East African countries using genome-scan data to detect polymorphisms in 22 genes known to affect malaria risk. We fit generalized linear mixed models to estimate odds ratios (OR) and 95% confidence intervals (95% CI), controlling for age, sex, country, and ancestry. The ORs of the loci with BL and P. falciparum infection among controls were correlated (Spearman's ρ = 0.37, p = .039). HBB-rs334(T) was associated with lower P. falciparum infection risk among controls (OR = 0.752, 95% CI 0.628-0.9; p = .00189) and BL risk (OR = 0.687, 95% CI 0.533-0.885; p = .0037). ABO-rs8176703(T) was associated with decreased risk of BL (OR = 0.591, 95% CI 0.379-0.992; p = .00271), but not of P. falciparum infection. Our results increase support for the etiological correlation between P. falciparum and BL risk.

Blood rheology and vascular function in sickle cell trait and sickle cell disease: From pathophysiological mechanisms to clinical usefulness.

Sickle cell disease (SCD) is an autosomal recessive disorder. Although the molecular mechanisms at the origin of SCD have been well characterized, its clinical expression is highly variable. SCD is characterized by blood rheological abnormalities, increased inflammation and oxidative stress, and vascular dysfunction. Individuals with only one copy of the mutated ß-globin gene have sickle cell trait (SCT) and are usually asymptomatic. The first part of this review focuses on the biological responses of SCT carriers during exercise and on the effects of combined SCT and diabetes on vascular function, several biomarkers and clinical complications. The second part of the review focuses on SCD and shows that the magnitude of red blood cell (RBC) rheological alterations is highly variable from one patient to another, and this variability reflects the clinical and hematological variability: patients with the less deformable RBCs have high hemolytic rate and severe anemia, and are prone to develop leg ulcers, priapism, cerebral vasculopathy, glomerulopathy or pulmonary hypertension. In contrast, SCD patients characterized by the presence of more deformable RBCs (but still rigid) are less anemic and may exhibit increased blood viscosity, which increases the risk for vaso-occlusive events. Several genetic and cellular factors may modulate RBC deformability in SCD: co-existence of α-thalassemia, fetal hemoglobin level, oxidative stress, the presence of residual mitochondria into mature RBCs, the activity of various non-selective cationic ion channels, etc. The last part of this review presents the effects of hydroxyurea and exercise training on RBC rheology and other biomarkers in SCD.

Delayed Plasmodium falciparum Malaria in Pregnant Patient with Sickle Cell Trait 11 Years after Exposure, Oregon, USA.

Delayed Plasmodium falciparum malaria in immigrants from disease-endemic countries is rare. Such cases pose a challenge for public health because mosquitoborne transmission must be rigorously investigated. We report a case of delayed P. falciparum malaria in a pregnant woman with sickle cell trait 11 years after immigration to the United States.

Cold exposure induces vaso-occlusion and pain in sickle mice that depend on complement activation.

Vaso-occlusive pain episodes (VOE) cause severe pain in patients with sickle cell disease (SCD). Vaso-occlusive events promote ischemia/reperfusion pathobiology that activates complement. We hypothesized that complement activation is linked to VOE. We used cold to induce VOE in the Townes sickle homozygous for hemoglobin S (HbSS) mouse model and complement inhibitors to determine whether anaphylatoxin C5a mediates VOE. We used a dorsal skinfold chamber to measure microvascular stasis (vaso-occlusion) and von Frey filaments applied to the plantar surface of the hind paw to assess mechanical hyperalgesia in HbSS and control Townes mice homozygous for hemoglobin A (HbAA) mice after cold exposure at 10°C/50°F for 1 hour. Cold exposure induced more vaso-occlusion in nonhyperalgesic HbSS mice (33%) than in HbAA mice (11%) or HbSS mice left at room temperature (1%). Cold exposure also produced mechanical hyperalgesia as measured by paw withdrawal threshold in HbSS mice compared with that in HbAA mice or HbSS mice left at room temperature. Vaso-occlusion and hyperalgesia were associated with an increase in complement activation fragments Bb and C5a in plasma of HbSS mice after cold exposure. This was accompanied by an increase in proinflammatory NF-κB activation and VCAM-1 and ICAM-1 expression in the liver. Pretreatment of nonhyperalgesic HbSS mice before cold exposure with anti-C5 or anti-C5aR monoclonal antibodies (mAbs) decreased vaso-occlusion, mechanical hyperalgesia, complement activation, and liver inflammatory markers compared with pretreatment with control mAb. Anti-C5 or -C5aR mAb infusion also abrogated mechanical hyperalgesia in HbSS mice with ongoing hyperalgesia at baseline. These findings suggest that C5a promotes vaso-occlusion, pain, and inflammation during VOE and may play a role in chronic pain.

Association of sickle cell trait with adverse pregnancy outcomes in a population-based cohort.

INTRODUCTION: Sickle cell trait (SCT) is common in African descendants. Its association with several adverse pregnancy outcomes (APOs) has been reported but remains inconsistent. The objectives of this study are to test associations of SCT with APOs in non-Hispanic Black women, including (1) validate the associations of SCT with previously reported APOs, (2) test novel associations of SCT with broad spectrum of APOs, and (3) estimate the attributable risk of SCT for implicated APOs. MATERIAL AND METHODS: This is a retrospective analysis of a prospectively designed population-based cohort. Women/participants were self-reported non-Hispanic Black women from the UK Biobank (UKB). SCT status was determined based on heterozygous Glu6Val in the HBB gene. Several APOs were studied, including four previously reported SCT-associated APOs (preeclampsia, bacteriuria, pregnancy loss, and preterm delivery), and broad conditions related to pregnancy, childbirth, and the puerperium. APOs were curated by experts' peer review and consensus processes. Associations of SCT with APOs were tested by estimating its relative risk and 95% confidence interval (95% CI), adjusting for number of live births and age at first birth. Attributable risk proportion (ARP) and population attributable risk proportion (PARP) of SCT to APOs were estimated. RESULTS: Among the 4057 self-reported non-Hispanic Black women with pregnancy records in the UKB, 581 (14.32%) were SCT carriers. For four previously reported SCT-associated APOs, two were confirmed at a nominal P < 0.05; relative risk (RR) was 2.39 (95% CI 1.09-5.23) for preeclampsia, and 4.85 (95% CI 1.77-13.27) for bacteriuria. SCT contributed substantially to these two APOs among SCT carriers, with attributable risk proportion estimated at 61.00% and 68.96% for preeclampsia and bacteriuria, respectively. SCT also contributed substantially to these two APOs in the population (self-reported Black UK women), with population attributable risk proportion estimated at 18.30% and 24.14% for preeclampsia and bacteriuria, respectively. In addition, novel associations were found for seven other APOs (nominal P < 0.05). CONCLUSIONS: SCT is significantly associated with APOs in this study and contributes substantially to APOs among self-reported Black women in the UK. Confirmation of these findings in independent study populations is required.

Evaluation of Homocysteine Status and its Correlation with Disease Severity in Individuals with Sickle Cell Anaemia in Steady State.

INTRODUCTION: Sickle cell anaemia (SCA) is a genetic disorder associated with chronic inflammation and a hypercoagulable state. This study evaluated the serum homocysteine level and its correlation with disease severity and body mass index (BMI) among individuals with SCA in a steady state. METHODS: A cross-sectional study was carried out and the serum level of homocysteine was analysed using the ELISA method. Disease severity and BMI were also calculated. Data generated were analyzed using SPSS software, version 21. RESULTS: Ninety subjects participated in this study and were made up of 30 homozygous sickle cell (HbSS, SCA) subjects, 30 individuals with sickle cell trait (HbAS), and 30 individuals with normal adult haemoglobin (HbAA) with a mean age of 27.3 ± 6.4years, 26.0 ± 6.0years, and 27.2 ± 6.6years respectively. The mean serum level of homocysteine among HbSS was 26.2 ± 11.8umol/l which was significantly higher than 17.9 ± 8.0umol/l and 18.9 ± 7.9umol/l among HbAA or HbAS respectively (p< 0.05). Mean BMI of 21.9 ± 2.8kg/m2 among HbSS was significantly lower than those of HbAS (23.7 ± 2.5kg/m2) and HbAA (24.7 ± 2.4kg/m2) (p<0.05). There was a positive correlation between homocysteine level and disease severity in patients with HbSS, though not significant (r = 0.168; p>0.05). There was a significant negative correlation between homocysteine level and BMI(r = -0.0258; p = 0.021); and between disease severity and BMI (r = -0.400; p = 0.028). CONCLUSION: Individuals with HbSS have significantly higher mean serum homocysteine level and lower BMI compared to HbAS and HbAA. There was a positive correlation between homocysteine level and disease severity, though not significant but a strong negative correlation between homocysteine levels and BMI, and between disease severity and BMI among HbSS participants. A similar study should be carried out on a wide scale to determine the actual relationship between homocysteine level and disease severity in SCA and whether patients will benefit from routine administration of vitamin B12, vitamin B6, and folic acid.

INTRODUCTION: La drépanocytose est une maladie génétique associée à une inflammation chronique et à un état d'hypercoagulabilité. Cette étude a évalué le taux d'homocystéine sérique et sa corrélation avec la gravité de la maladie et l'indice de masse corporelle (IMC) chez les personnes atteintes d'anémie drépanocytaire à l'état stable. MÉTHODES: Une étude transversale a été réalisée et le taux sérique d'homocystéine a été analysé à l'aide de la méthode ELISA. La gravité de la maladie et l'IMC ont également été calculés. Les données générées ont été analysées à l'aide du logiciel SPSS, version 21. RÉSULTATS: Quatre-vingt-dix sujets ont participé à cette étude, dont 30 drépanocytaires homozygotes (HbSS, SCA), 30 drépanocytaires de trait (HbAS) et 30 personnes ayant une hémoglobine adulte normale (HbAA), âgés en moyenne de 27,3 ±6,4 ans, 26,0 ±6,0 ans et 27,2 ±6,6 ans, respectivement. Le taux sérique moyen d'homocystéine chez les HbSS était de 26,2 ±11,8 umol/l, ce qui était significativement plus élevé que 17,9 ±8,0umol/l et 18,9 ±7,9umol/l chez les HbAA ou HbAS respectivement (p< 0,05). L'IMC moyen de 21,9 ±2,8kg/m2 chez les HbSS était significativement inférieur à celui des HbAS (23,7±2,5kg/m2) et des HbAA (24,7 ±2,4kg/ m2) (p<0,05). Il y avait une corrélation positive entre le niveau d'homocystéine et la sévérité de la maladie chez les patients HbSS, bien que non significative (r= 0.168 ; p>0.05). Il existe une corrélation négative significative entre le taux d'homocystéine et l'IMC (r= - 0,0258 ; p = 0,021) ; et entre la gravité de la maladie et l'IMC (r = - 0,400 ; p = 0,028). CONCLUSION: Les personnes atteintes de HbSS ont un taux moyen d'homocystéine sérique significativement plus élevé et un IMC plus faible que les personnes atteintes de HbAS et de HbAA. Il existe une corrélation positive entre le taux d'homocystéine et la gravité de la maladie, une corrélation négative non significative mais forte entre le taux d'homocystéine et l'IMC, et entre la gravité de la maladie et l'IMC chez les participants HbSS. Une étude similaire devrait être menée à grande échelle pour déterminer la relation réelle entre le taux d'homocystéine et la gravité de la maladie dans le SCA et pour savoir si les patients bénéficieront de l'administration systématique de vitamine B12, de vitamine B6 et d'acide folique. Mots clés: Gravité de la maladie, homocystéine, anémie drépanocytaire.

Association of Sickle Cell Trait on Career and Operational Outcomes in the United States Air Force.

INTRODUCTION: Sickle cell trait (SCT) is a heterozygotic state defined by having one normal hemoglobin gene and one sickle hemoglobin gene. Individuals with SCT are at increased risk for negative health outcomes during intense physical exertion, especially in hot climates and high-elevation locations, or when dehydrated. The U.S. Air Force mitigates this risk through universal screening after accession followed by education of SCT-positive airmen. Airmen who are SCT positive but remain asymptomatic are not restricted in occupation choice or deployment/duty locations based on their SCT status. Previous studies have analyzed the relationship between SCT and health and fitness outcomes. The objective of this study was to analyze the relationship between SCT and career and operational outcomes in a large cohort of airmen and secondarily to analyze the relationship between hemoglobin S (HgbS) percentage and these outcomes. METHODS: This is a retrospective cohort study of all recruits who entered U.S. Air Force (USAF) Basic Military Training (BMT) between January 2009 and December 2013. The SCT status was assessed through a sickle solubility test. Hemoglobin electrophoresis permitted subgroup analysis of SCT-positive individuals by HgbS percentage. The following career and operational outcomes were assessed: BMT graduation; retention at 4 and 6 years; promotion to the rank of staff sergeant by 4 and 6 years; overseas deployment and number of deployments within 6 years; and high-elevation assignment and cumulative months at a high-elevation assignment within 6 years. Multivariable logistic regression was used to assess all binary outcomes, controlling for age, sex, and race, to produce adjusted odds ratios (aORs) with 95% confidence intervals (CIs). Multivariable Poisson regression was used to assess cumulative count outcomes and to produce adjusted incidence rate ratios (aIRRs) with 95% CIs. Attrition from BMT by SCT status was also assessed as a hazards function using the Kaplan-Meier approach with Cox proportional hazards. RESULTS: A total of 180,355 civilians entered USAF BMT during the 5-year surveillance period, of whom 169,837 graduated and had data available for analysis. Compared to their SCT-negative peers, SCT-positive airmen (n = 1,697) had 26% lower adjusted odds of promotion to staff sergeant within 4 years of BMT graduation (aOR = 0.74; 95% CI: 0.59-0.92) and served less time at a high-elevation assignment during their first 6 years (aIRR = 0.88; 95% CI: 0.85-0.91). The SCT status was not associated with statistically significant differences in BMT graduation, retention at 4 and 6 years, promotion to staff sergeant by 6 years, likelihood or number of overseas deployments, and likelihood of ever working at a high-elevation assignment. Retention at 4 and 6 years was inversely associated with HgbS percentage. CONCLUSIONS: SCT-positive and SCT-negative airmen had similar career and operational outcomes, with two exceptions: SCT-positive airmen were less likely to be promoted to staff sergeant within 4 years, and they spent less time at a high-elevation location during their first 6 years of service. The underlying explanation of these findings should be explored with an aim to support SCT-positive airmen and to reduce potentially unwarranted discrepancies. Efforts should continue to reduce the stigma associated with SCT.

Proliferative Retinopathy Associated with Repeated High-Altitude Exposure in a Patient with Sickle Cell Trait.

Broadhead Geoffrey K., Henry E. Wiley, David Peprah, Kenneth Olumba, and Alisa T. Thavikulwat. Proliferative retinopathy associated with repeated high-altitude exposure in a patient with sickle cell trait. High Alt Med Biol. 23:369-371, 2022.-Sickle cell trait (SCT), a carrier state characterized by one normal copy of the beta-globin gene (producing hemoglobin A) and one abnormal variant (producing hemoglobin S), is typically asymptomatic and very low risk for manifestations of hemoglobinopathy, including development of retinopathy. Reported cases of proliferative retinopathy in patients with SCT have occurred in the context of concurrent ocular or systemic disease. We report a case of an otherwise healthy patient with SCT who developed proliferative retinopathy requiring surgical intervention in the setting of significant exposure to high altitude through increased work hours as a flight attendant in the month leading to her presentation. Significant high-altitude exposure may contribute to development of retinopathy in patients with sickle trait. Practitioners should consider the possibility of sickle cell retinopathy in patients with sickle trait in these circumstances.

COVID-19 outcomes in sickle cell disease and sickle cell trait.

Throughout the Coronavirus Disease 2019 (COVID-19) pandemic, understanding the effects of COVID-19 on persons with Sickle Cell Disease (SCD) and Sickle Cell Trait (SCT) has garnered interest. Patients with SCD diagnosed with COVID-19 utilize the emergency department and are hospitalized at significantly higher rates compared to the general population, with vaso-occlusive crisis and acute chest syndrome as the leading presentations. Whether SCD alone increases the likelihood of severe COVID-19 illness remains uncertain; however, potential risk factors for severe disease among patients with SCD include older age, frequent acute care visits for pain, haemoglobin SC disease, and pre-existing end-organ disease. SCT status may also influence COVID-19 outcomes, particularly among those with pre-existing co-morbidities. Corticosteroids in patients with SCD and COVID-19 should be used with extreme caution given strong associations between corticosteroid exposure and severe vaso-occlusive crisis, with prophylactic transfusion administered if corticosteroids are deemed necessary. Hydroxyurea may be protective in COVID-19.

Prevalence of Cardiovascular Complications in Individuals with Sickle Cell Anemia and Other Hemoglobinopathies: A Systematic Review. / Prevalência das Complicações Cardiovasculares nos Indivíduos com Anemia Falciforme e Outras Hemoglobinopatias: Uma Revisão Sistemática.

BACKGROUND: Sickle cell anemia (SCA) is a hereditary disease whose cardiovascular complications are the main cause of death, the same being observed in other hemoglobinopathies. Early identification of these changes can favorably modify the course of the disease. OBJECTIVE: To compare the prevalence of cardiovascular complications between individuals with SCA and individuals with other hemoglobinopathies. METHOD: Following the recommendations of the PRISMA protocol, a systematic literature review was carried out with searches in PubMed/Medline databases, associated with a manual search. Studies that analyzed the prevalence of cardiovascular alterations in hemoglobinopathies (SCA, sickle cell trait, SC hemoglobinopathy, alpha-thalassemia and beta-thalassemia) were included. The methodological quality of the articles was assessed using the Newcastle-Ottawa scale. RESULTS: Four studies were selected for analysis, resulting in a sample size of 582 participants: 289 with SCA, 133 with SC hemoglobinopathy, 40 with beta-thalassemia, 100 healthy individuals and none with alpha-thalassemia or sickle cell trait. Dilatation of the cardiac chambers, left and right ventricular hypertrophy, pulmonary hypertension, diastolic dysfunction, mitral regurgitation and tricuspid regurgitation are more prevalent in SCA than in the other hemoglobinopathies considered. Myocardial iron overload is more frequent in thalassemia major than in sickle cell anemia. Systolic function is similar between different hemoglobinopathies. CONCLUSION: There is greater cardiovascular impairment in individuals with SCA than in those with other hemoglobinopathies, reinforcing the necessity for regular cardiovascular follow-up in sickle cell patients.

FUNDAMENTO: A anemia falciforme (AF) é uma doença hereditária cujas complicações cardiovasculares são a principal causa de morte, o mesmo sendo observado em outras hemoglobinopatias. A identificação precoce dessas alterações pode modificar favoravelmente o curso da doença. OBJETIVO: Comparar a prevalência de complicações cardiovasculares entre indivíduos com AF e indivíduos com outras hemoglobinopatias. MÉTODOS: Seguindo recomendações do protocolo PRISMA, realizou-se revisão sistemática da literatura com buscas nas bases de dados PubMed/Medline, associadas à busca manual. Incluídos estudos que analisaram a prevalência das alterações cardiovasculares nas hemoglobinopatias (AF, traço falciforme, hemoglobinopatia SC, alfatalassemia e betatalassemia). A qualidade metodológica dos artigos foi realizada pela escala de Newcastle-Ottawa. RESULTADOS: Foram selecionados para análise quatro estudos, resultando em um tamanho amostral de 582 participantes: 289 portadores de AF, 133 possuem hemoglobinopatia SC, 40 com betatalassemia, 100 indivíduos saudáveis e nenhum com alfatalassemia ou traço falcêmico. Dilatação das câmaras cardíacas, hipertrofia ventricular esquerda e direita, hipertensão pulmonar, disfunção diastólica, insuficiência mitral e insuficiência tricúspide são mais prevalentes na AF do que nas demais hemoglobinopatias consideradas. A sobrecarga miocárdica de ferro é mais frequente na talassemia maior do que na AF. A função sistólica foi similar entre as hemoglobinopatias. CONCLUSÃO: Verificou-se maior comprometimento cardiovascular nos indivíduos com AF do que naqueles com as demais hemoglobinopatias, reforçando a necessidade de acompanhamento cardiovascular regular e frequente nos pacientes falcêmicos.

[Renal infarction in an adolescent carrier of the sickle cell trait]. / Infarctus rénal chez un adolescent porteur d'un trait drépanocytaire.

We report the case of a 15-year-old teenager, carrier of the sickle cell trait (haemoglobin AS), who presented a renal infarction. Besides, the patient also presented a renal ectopia. It is tempting to link these two particularities and the ischemic attack. The kidney is a target of this hemoglobinopathy, in its homozygous and possibly even heterozygous form. However, the analysis of the literature does not retain renal vascular accidents as a complication of sickle cell trait. Kidney position abnormalities also do not appear to be a contributing factor. It is, however, necessary to be attentive in adult heterozygous subjects to a faster than normal decline in glomerular filtration. The search for other risk factors (hypertension, diabetes, dyslipaemia) is desirable. The implementation of specific monitoring requires additional work.

Nous rapportons le cas d'un adolescent de 15 ans, porteur du trait drépanocytaire (hémoglobine AS), ayant présenté un infarctus rénal. Le patient présentait, par ailleurs, une ectopie rénale. Il est tentant de relier ces deux particularités et l'accident ischémique. Le rein est une cible de cette hémoglobinopathie, dans sa forme homozygote et peut-être même hétérozygote. Toutefois, l'analyse de la littérature ne retient pas les accidents vasculaires rénaux comme complication du trait drépanocytaire. De même, les anomalies de position du rein n'apparaissent pas comme facteur favorisant. Il faut cependant être attentif, chez les sujets hétérozygotes adultes, à un déclin de la filtration glomérulaire plus rapide que la normale. La recherche d'autres facteurs de risque (hypertension, diabète, dyslipémie) est souhaitable. La mise en place d'un suivi spécifique requiert des travaux complémentaires.