Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0002895 (sickle cell disease)
 11,747 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Erythropoietin is a glycoprotein hormone that plays a vital role in erythropoiesis. It is mainly produced in the fetal liver till the third trimester of pregnancy. At that point, the kidney interstitium takes over this function and becomes the main source of erythropoietin. Hypoxia stimulates erythropoietin production by a mechanism that may require a heme protein as a second messenger. Erythropoietin stimulates the maturation of erythroid precursors (colony-forming unit-erythroid and burst-forming unit-erythroid) via at least two types of cell surface receptors. The higher-affinity receptors appear to be more important in modulating the effects of erythropoietin in vivo. Changes in intracellular calcium may ultimately mediate the action of erythropoietin on erythroid precursors. A specific and sensitive radioimmunoassay is now available for accurately measuring erythropoietin levels. All forms of erythrocytosis except polycythemia vera are associated with elevated erythropoietin levels. Levels are also high in cord blood obtained following fetal asphyxia. Reduced levels are seen in patients with anemia due to renal diseases. The response of erythropoietin to the degree of anemia appears to be attenuated in patients with cancer, chronic diseases, and human immunodeficiency virus (HIV) infection. Erythropoietin has been successfully used for treating patients with anemia due to renal failure. Its use has also been approved for the treatment of anemia patients receiving zidovudine for HIV infection. Encouraging results have been observed when erythropoietin was used to treat anemia due to rheumatoid arthritis, hematological malignancies, and prematurity. It has also been used to increase the yield of autologous blood collected prior to an elective surgical procedure. However, it has not proved to be useful in sickle cell anemia and myelodysplastic syndromes.
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PMID:Erythropoietin. Biology and clinical applications. 178 66

Africa is the continent most severely affected by the pandemic of immunodeficiency viruses (HIV-1 and HIV-2). Nowadays (1990), at least 3 million individuals are infected and about 300,000 cases of acquired immunodeficiency syndrome (AIDS) have been recorded. HIV infections started in the seventies as sporadic cases in remote areas and spread throughout black Africa where they are now epidemic, with high seroprevalence (1p. 100-20 p. 100), even in the general population. Due to heterosexual transmission, the groups at highest risk are female prostitutes and their customers and people with genital ulcers and/or sexually transmitted diseases (STDs). The vertical infection rates remain uncertain but may be estimated at 40 to 65 p. 100 of pregnancies in HIV-infected mothers. Blood transfusions are the third mode of infection because of high demands for blood (sometimes not tested) arising from severe anaemias in children (malaria and sickle cell anaemia), in pregnant women and in patients needing surgery. STDs causing ulcers undoubtedly are cofactors in the invasion by HIV, while the most important cofactors in AIDS progression are recurrent STDs, chronic activation of the immune system and repeated pregnancies that activate HIV-infected lymphocytes. The minimum mortality rate of AIDS is about 1 in 5000. Spatial, cultural and demographic factors should also be taken into consideration for all AIDS control programmes which must be integrated into the primary health care systems of African states.
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PMID:[Epidemiology of HIV infections in Africa]. 223 19

The prevalence of the human immunodeficiency virus (HIV) antibody and the human T cell leukemia virus type I (HTLV-I) antibody was examined in 116 adults with sickle cell disease. Eighty-eight of them had received a mean of 18.6 transfusions of red blood cells between 1978 and 1985, and none was positive for the HIV antibody. Of 116 patients, 9 (7.8%) tested positive for HTLV-I antibodies. HTLV-I-positive patients were similar to those without HTLV-I antibody with respect to age, number of transfusions, and proportion of patients with greater than 40 transfusions. However, 3 of the 9 HTLV-I-positive patients came from West Africa or from the Caribbean, whereas this proportion was much lower (7/107) in the HTLV-I-negative group (x2, 7.564; P less than .01). Our analysis suggests that the risk of HIV infection in transfused sickle cell disease patients is low. Although HTLV-I antibodies in these patients may not be related to blood transfusions, it seems prudent to screen blood donors for HTLV-I infection.
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PMID:Prevalence of antibodies to human immunodeficiency virus and to human T cell leukemia virus type I in transfused sickle cell disease patients. 238 98

About 120,000 infants are born each year with sickle cell disease (SCD) in Africa. The majority have Hb SS, but Hb SC and Hb S/beta+ thalassaemia are common in west Africa. The development of Plasmodium falciparum and P. malariae is partially inhibited in the Hb SS red cells, but malaria precipitates both haemolytic and infarctive crises, and is the commonest and most important cause of morbidity and mortality. The pneumococcus is likely to be the second major infectious cause of sickness and death. In one rural community, there were less than 2% of the expected number of subjects with SCD surviving beyond 5 years of age. Genetic factors improving prognosis include (1) the Senegal beta chain haplotype, which is linked to a high level of Hb F, and (2) alpha+ thalassaemia. Of environmental factors improving prognosis, the family is of first importance. The commonest age of presentation is 1-3 years. Children present with anaemic crises (malaria, splenic sequestration, folate deficiency, and possibly aplastic), infarctive crises (hand-foot syndrome, bone-pain, pulmonary and abdominal) or acute infections (malaria, pneumonia, septicaemia, meningitis, osteomyelitis). Tragically, many patients in central Africa have been infected by the human immunodeficiency virus (HIV) through blood transfusions; they present with generalised lymphadenopathy and other features of the acquired immunodeficiency syndrome (AIDS). The principles of management are (1) to ensure freedom from malaria, (2) to continue folic acid supplements, (3) to give blood transfusions only when anaemia endangers life, (4) to control pain, (5) to restore hydration, and (6) to prescribe broad spectrum antibiotics in large dosage and without delay, but only when there are definite indications, such as fever (greater than 39 degrees C), acute pulmonary disease, meningitis, and acute osteomyelitis. The advent of HIV and AIDS makes the control of SCD of even greater importance. Principles of control are (1) early diagnosis through appropriate laboratory techniques and selective screening, (2) education of parents, patients, health professionals and public, and (3) the maintenance of health at sickle cell clinics; measures must include antimalarial prophylaxis. SCD programmes should be integrated with primary health care and AIDS control programmes.
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PMID:The presentation, management and prevention of crisis in sickle cell disease in Africa. 265 Jul 73

A 21-year-old black man with sickle cell disease who has received blood transfusions for 11 years because of recurrent stroke has had a decline in numbers of circulating lymphocytes and T4 cells over the past four years. Two and a half years ago persistent generalized lymphadenopathy developed, associated with a positive test for human immunodeficiency virus (HIV) antibody. For the past seven months he has had a pruritic maculopapular rash, primarily on the extensor surfaces of the extremities. Multiple skin biopsies revealed only nonspecific perivascular infiltrates of mononuclear cells. This rash appears to be an unusual manifestation of HIV infection, and may be an indicator of impending AIDS.
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PMID:Unusual chronic maculopapular rash associated with human immunodeficiency virus infection. 292 31

Thirty-one documented acquired immune deficiency syndrome (AIDS) cases occurred in Panama during 1984-1987. Twenty-three (74%) patients were homosexual males and all but 2 patients recognized prior to June 1987 have died. To identify risk factors for human immunodeficiency virus infection, 287 male homosexual residents of Panama City were enrolled in a cross-sectional study. Nine had human immunodeficiency virus (HIV) antibody. Travel to the United States, homosexual relations with United States nationals in Panama, and sexual contacts in Panamanian clubs and bars were associated with human immunodeficiency virus infection by logistic regression analysis. Number of different male sex partners per year was identified but did not enter the logistic model at a significant level. To estimate seroprevalence in other high risk populations, 183 Panama City female prostitutes and 55 homosexual males from the rural Azuero peninsula were screened; none were seropositive. Eighty-four percent of Panamanian hemophiliacs had antibody; infection was related to factor VIII transfusions. Two of 182 sickle cell anemia patients and 15 of 7,720 volunteer blood donors were positive.
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PMID:Human immunodeficiency virus infection in the Republic of Panama. 318 1

Routine obstetric screening for all patients should include a Pap smear, urinalysis and urine culture, complete blood count, blood type, Rh factor and direct Coombs' test. Patients should also be screened for syphilis, rubella, gonorrhea and diabetes. For patients at high risk for certain conditions, additional studies of value include obstetric ultrasound, amniocentesis, serum alpha-fetoprotein level and screening for sickle cell anemia, herpes, hepatitis B, Chlamydia and human immunodeficiency virus.
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PMID:Prenatal screening. 328 2

Progressive lymphadenopathy in a previously healthy female adult with homozygous sickle cell disease (SCD) was found to be due to infection with the human immunodeficiency virus (HIV). Detailed questioning identified several risk factors for HIV in this apparently low-risk patient. Parenteral therapy and heterosexual relationships while abroad may place such SCD patients at risk of HIV infection and its sequelae. The additional risk due to the underlying immunological abnormalities which have been identified in SCD patients is unclear in the absence of prospective studies or reported cases.
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PMID:Unexplained lymphadenopathy in sickle cell disease. 334 28

Zinc deficiency is a common nutritional problem observed both in human and in animal populations that has profound effects on host defense mechanisms. Using the young adult mouse as a model, it has been demonstrated that a moderate period of suboptimal zinc causes thymic atrophy, lymphopenia, and alterations in the proportions of the various subsets of lymphocytes and mononuclear phagocytes. As a result, antibody-mediated responses to both T cell-dependent and T cell independent antigens are significantly reduced. Cytolytic T cell responses, natural killer (NK) cell activity, and delayed-type hypersensitivity (DTH) reactions are also depressed. Suboptimal zinc during in utero development of mice causes persistent states of immunodeficiency in the offspring that can even be transferred to subsequent generations. In regard to human immunological consequences of zinc deficiency, patients with the genetic disorder of zinc absorption, acrodermatitis enteropathica, also exhibit atrophic thymuses, lymphopenia, anergic DTH responses, and reduced NK cell activity. Patients suffering from sickle cell anemia or uremia with associated deficiencies in zinc exhibit similar immune deficiencies. An additional outcome of these studies has been shown to be an essential cofactor for thymulin, one of the thymic hormones. Furthermore, addition of zinc salts to culture can polyclonally activate lymphocytes as well as augment responses to mitogens in adjuvant-like manner.
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PMID:Interrelationships between zinc and immune function. 348 44

We present the findings in a patient having sickle cell disease who developed multilobar pneumonia. Cultures of bronchial aspirates and histologic specimens grew Cryptococcus neoformans. There was neither spontaneous clearing of the infection nor a response to bactericidal antibiotics. The patient had no underlying malignant neoplasm or immunodeficiency as indicated by history, physical examination, and specialized tests of humoral and cell-mediated immunity.
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PMID:Cryptococcal pneumonia in a patient with sickle cell disease. 370 57


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