2 What is Sickle Cell Anemia (SCA)? First described in Chicago in 1910 by James Herrick as an inherited condition that results in a decrease in the ability of red blood cells to carry oxygen throughout the bodySickle red blood cells become hard and irregularly shaped (resembling a sickle)Become clogged in the small blood vessels and therefore do not deliver oxygen to the tissues.Lack of tissue oxygenation can cause excruciating pain, damage to body organs and even death.
3 Mechanism Red blood cells (RBC) Contain a special protein called haemoglobin (Hb)Hb is the component that carries oxygen from the lungs to all parts of the bodyMost people have only hemoglobin type – Hb A within RBC (normal genotype: Hb AA)Sickle Cell: HbSS similar to A, but one structural changeOther types: HbC, HbD, and HbE
4 Mechanism -HbSWhen sickle haemoglobin (HbS) gives up its oxygen to the tissues, HbS sticks togetherForms long rods form inside RBCRBC become rigid, inflexible, and sickle-shapedUnable to squeeze through small blood vessels, instead blocks small blood vesselsLess oxygen to tissues of bodyRBCs containing HbS have a shorter lifespanNormally 120 daysChronic state of anaemia
5 Genetics HbS –Recessive S=Sickle A=Normal 2 copies of the gene for Hb (each parent)HbS –RecessiveS=SickleA=Normal
6 Sickle Cell TraitSickle haemoglobin (S) + Normal haemoglobin (A) in RBCAdequate amount of normal Hb (A) in red blood cellsRBC remain flexibleCarrierDo Not have the symptoms of the sickle cell disorders, with 2 exceptionsPain when Less Oxygen than usual (scuba diving, activities at high altitude (12,000ft), under general anaesthesia)Minute kidney problems
7 Three common types of Sickle Cell Disorders Sickle Cell Anemia Sickle haemoglobin (HbS) + Sickle haemoglobin (HbS)Most Severe – No HbA
8 Other Sickling Disorders Other types of Hb combine with sickle HbHemoglobin S-C diseaseSickle haemoglobin (HbS) + (HbC)Hemoglobin S-Beta thalassemiaBeta thalassaemia gene reduces the amount of HbA that can be madeSickle haemoglobin (HbS) + reduced HbAMilder form of Sickle Cell Disorder than sickle cell anemia
9 Some Genetic HistoryThe error in the hemoglobin gene results from a genetic mutation that occurred many thousands of years ago in people in parts of Africa, the Mediterranean basin, the Middle East, and India.A deadly form of malaria was very common at that timeMalaria epidemics caused the death of manyIn areas where malaria was a problem, children who inherited one sickle hemoglobin gene and who, therefore, carried the sickle cell trait - had a survival advantage.Unlike the children who had normal hemoglobin genes, they survived the malaria epidemics they grew up, had their own children, and passed on the gene- for sickle hemoglobin.
11 HistoryAs populations migrated, the sickle cell-mutation spread to other Mediterranean areas, further into the Middle East and eventually into the Western Hemisphere.In the United States and other countries where malaria is not a problem, the sickle hemoglobin gene no longer provides a survival advantage.Instead, it may be a serious threat to the carrier's children, who may inherit two abnormal sickle hemoglobin genes and have sickle cell anemia.
12 Who is at risk? Most common in Africans and African Americans. East Asia, Southern Italy, Saudi Arabia, India, Egypt, South and Central American, Cuba, the Caribbean, Greece, and Iran, and Eastern Jews have also been found to have a form of this illness.
13 Prevalence More than 2.5 million Americans have the trait 70,000 or more Americans have sickle cell diseaseAbout 1,000 babies are born with the disease each year in AmericaIn Nigeria, 1/3 population of U.S., 45,000-90,000 babies with sickle cell disease are born each year
14 Among African - Americans 1 in 12 have Sickle Cell Trait (Hb SA)1 in 600 have Sickle Cell Anemia (Hb SS)1 in 1500 have Sickle C Disease (Hb SC)1 in 350 have Sickle Cell Disease (Hb SS, SC, S-Beta-Thal)Among Latinos1 in 172 have Sickle Cell Trait (Hb AS)1 in 1,000 have Sickle Cell Disease (Hb SS, SC, S-Beta-Thal)
15 Screening Haemoglobin Electrophoresis Prenatal Testing Amniocentesis Simple Blood testRoutine screening in high risk groupsDuring pregnancyBefore anaesthesiaPrenatal TestingAmniocentesis16 and 18 weeks of the pregnancysmall risk of causing a miscarriage (1 in 100)Chorionic villus sampling (CVS)9th or 10th week of pregnancyvery small amount of material from the developing placentaslightly higher chance of miscarriage
16 Early Symptoms and Complications Typically appear during infant's first year1st symptom: dactylitis and fever (6 mo-2 yrs)Pain in the chest, abdomen, limbs and jointsEnlargement of the heart, liver and spleen nosebleedsFrequent upper respiratory infectionsChronic anemia as children grow olderOver time Sickle Cell sufferers can experience damage to organs such as liver, kidney, lungs, heart and spleenCan result in death
17 Medical Complications kidney damage andloss of body water in urinepainful erections in men (priapism)blood blockage in the spleen or liver (sequestration)eye damagelow red blood cell counts (anemia)delayed growthpain episodesstrokesincreased infectionsleg ulcersbone damageyellow eyes or jaundiceearly gallstoneslung blockage
18 Serious Complications Infectious complicationsProminent early in lifeLeading cause of morbidity and mortalityGreat improvement in the prognosis related to newborn screening for sickle cell disease, vaccination for childhood illnesses, the use of prophylactic antibiotics, and aggressive diagnosis and treatment of febrile eventsAcute splenic sequestrationEpisodes of rapid increase in splenic size and decrease in hemoglobinPotential source of morbidity and mortality early in life for children with sickle cell anemia and at any age for those with Hb SC disease and sickle thalassemia
19 Serious Complications StrokesUp to 15% of children may have overt or silent strokes during childhoodChronic transfusion therapy reduces the recurrence rate of overt stroke which may approach 75% without interventionBone diseaseEarly risk is primarily from osteomyelitisInfectious usually painful inflammatory disease of bone often of bacterial origin and may result in bone tissue deathAvascular necrosis of the femur and humerusDeath of bone tissue due to disrupted blood supplyMarked by severe pain in the affected region and by weakened bone that may flatten and collapse
20 Serious Complications Leg ulcersSeen in patients older than 10 years of ageResistant to therapy and cause significant morbidityOphthalmic complicationsProliferative retinopathy, vitreous hemorrhage, & retinal detachmentPriapismDistressing complication that occurs at all agesDifficult to treatCauses a high incidence of impotenceChronic AnemiaAssociated with fatigue, irritability, jaundice, pain, delayed puberty, leg sores, eye problems, gum disease
21 Serious Complications: PAIN Recurrent Pain Episodes or Sickling Crises Occur at any age but appear to be particularly frequent during late adolescence and early adult lifeUnpredictableRed Blood Cells get stuck in the small veins and prevent normal blood flowCharacterized by severe pain in the back, chest, abdomen, extremities, and headHighly disruptive to lifeMost common reasons for individuals to seek health care
22 Danger Signs of a Crisis Any sudden weakness orloss of feelingPain that will not go awaywith home treatmentPriapism (painful erectionthat will not go down)Sudden vision changeFeverChest painShortness of BreathIncreasing tirednessAbdominal swellingUnusual headacheSEEK URGENT HOSPITAL TREATMENT IF IN CRISIS
23 Crises During a crisis severe pain in the fingers, toes, arms, joints,legs, back, abdomen, and bones.Decrease in oxygen to the chest and lungsMay lead to acute chest syndromeDamage to the lungsSevere pain and feverLungs' airways narrow, further reducing O2Leads to an increased risk of potentiallyfatal infections
24 Triggers of Pain Infections Thirst and dehydration caused by not drinking enough even if thirst is not feltOver-exertionOver-excitementCold weather and cold drinks and swimmingBangs, bumps, bruises and strainsStress triggers pain in adults, but does not seem to do so in children.
25 Predicting PainChildren and families can often tell when a severe sickle pain is coming on byThirstEyes turning yellow (jaundice),Sufferer being more irritable or tired than usual.
26 Alleviating Pain Warmth: increases blood flow Massaging and rubbing Heat from hot water bottles and deep heat creamsBandaging to support the painful regionResting the bodyCognitive Behavioral TherapyGetting the sufferer to relaxdeep breathing exercisesdistracting the attentionby other psychological methods.Pain-killing medicines (analgesics): paracetamol, codeine non-steroidal anti-inflammatory, morphine if necessary
27 Daily Preventative Measures Taking the folic acid (folate) daily to help make new red cellsDaily penicillin until age six to prevent serious infectionDrinking plenty of water daily (8-10 glasses for adults)Avoiding too hot or too cold temperaturesAvoiding over exertion and stressGetting plenty of restGetting regular check-ups from knowledgeable health care providers
28 Treating Complications Pain-killing drugs and oral and intravenous fluidsTo reduce pain and prevent complications.TransfusionsCorrect anemiaTreat spleen enlargement in children before the condition becomes life-threateningRegular transfusion therapy also can help prevent recurring strokes in children at high risk of crippling nervous system complications.
29 Psychosocial Issues Require regular medical attention Especially before and after operations, dental extraction and during pregnancy.Adherence to medical regimenVitamins, antibiotics, fluid intake, activity levelSchools must be involvedFamily planningSuitable types of employmentAir travelIncreased fluids, pain killers or oxygen may be recommended
30 Psychosocial IssuesChild should be encouraged to participate in sports, but not pushed passed their limitationsIf they are in pain or feel tired they should be allowed to rest and keep warm.They should have access to drinks.Strenuous exercise, dehydration and cold can induce a crisis.Strenuous outdoor activities should be avoided in cold or wet weatherShould only swim if the water is warm and care is taken to keep warm when leaving the waterIf develops a crisis despite these precautions he or she should avoid swimming all together
31 Psychosocial Issues Child Specific Issues: Coping with Pain Pain happens more oftenOn an average of one third of all daysLasts longerGenerally all day, even if not continuously all dayAssociated with great tiredness about half the timeCauses them to spend significant time in bedOn average the time spent wholly or partly in bed adds up to about a week of every school term.
32 Psychosocial Issues Variability and Unpredictability Some are mildly affected and largely free from pain, while others have frequent and severe painMost children go through good and bad patchesDoctors cannot predict who will be severely affected.No easily overt detectable signs of sickle painSo children known to have sickle cell disorder who say they are in pain must be trustedIf they can rely on the adults around them to take them seriously, they are less likely to take advantage of their condition to seek attention or avoid distasteful tasks.
33 Psychosocial IssuesTo reduce risk of crisis, children are encouraged to drink much more than normal and more frequentlyMay require about 1/4 litre of liquid every minutes.Child will need to go to the toilet more frequentlyMay increase risk of EnuresisBoys at risk for priapismMay be too embarrassed to mention to parentsSevere sickling can lead to impotence
34 Developing Treatments HydroxyureaThe first effective drug treatment for adults with severe sickle cell anemia reported in early 1995Daily doses of the anticancer drug, hydroxyurea, reduced the frequency of painful crises, acute chest syndrome, needed fewer blood transfusionsIncreases production of fetal hemoglobin in the bloodFetal hemoglobin seems to prevent sickling of red cellscells containing fetal hemoglobin tend to survive longer in the bloodstream
35 Developing Treatments Bone marrow transplantationShown to provide a cure for severely affected children with sickle cell diseaseOnly about 18 percent of children with sickle cell anemia are likely to have a matched sibling.
36 The Ultimate Cure? Gene Therapy Correcting the “defective gene” and inserting it into the bone marrowTurning off the defective gene and simultaneously reactivating another gene that turns on production of fetal hemoglobin.No real cure for Sickle Cell Anemia at this time.“In the past 30 years, the life expectancy of people with sickle cell anemia has increased. Many patients with sickle cell anemia now live into their mid-forties and beyond.”
37 Websites: Another Great Siteinformation, Counselling and Caring for those with Sickle Cell Disorders and their families: UK basedSickle Cell Disease Association of AmericaThe Human Genome Project Sickle Cell Education Site atAmerican Sickle Cell Anemia AssociationASCAA was founded in 1971 and is the oldest sickle cell research, education, and social services organization in the United States.
38 Sites for Kids http://www.sicklecellsociety.org/sicklescene/pshomf.htm Planet Sickle Cell Society (UK based)-Youth support, Poetry, Pen-Pals, Information, Message BoardThe STARBRIGHT Foundation is dedicated to the development of projects that empower seriousl ill children to combat the medical and emotional challenges they face on a daily basis.Coloring Books on Sickle Cell from Emory:
39 Support Group Information: Florida, Jacksonville: Sickle Cell Support Groups (904)Georgia, Atlanta: Parent SC Support Group (404)