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

A subset of 299 patients with homozygous sickle cell anaemia, enrolled in the cohort of the French Study Group on sickle cell disease (SCD), was investigated in this study. The majority of patients were children (mean age 10.1 +/- 5.8 yr) of first generation immigrants from Western and Central Africa, the others originated from the French West Indies (20.2%). We report the frequency of the main clinical events (mean follow-up 4.2 +/- 2.2 yr). The prevalence of meningitis-septicaemia and osteomyelitis was, respectively, 11.4% and 12% acute chest syndrome was observed in 134 patients (44.8%). Twenty patients (6.7%) developed stroke with peak prevalence at 10-15 yr of age. One hundred and seventy-two patients (58%) suffered from one or more painful sickle cell crises, while the others (42.5%) never suffered from pain. The overall frequency of acute anaemic episodes was 50.5%, (acute aplastic anaemia 46%; acute splenic sequestration 26%). A group of 27 patients were asymptomatic (follow-up > 3 yr). Epistatic mechanisms influencing SCD were studied. Coinherited alpha-thalassemia strongly reduced the risk of stroke (p <0.001) and increased that of painful crises (p < 0.02). There was a low prevalence of Senegal and Bantu (CAR) betas-chromosomes in patients with meningitis (p <0.04) and osteomyelitis (p < 0.03). Prevalence of Senegal betas-chromosomes was lower in the asymptomatic group of 27 patients (p < 0.02). The patients come from a population of unmixed immigrants in whom the beta-globin gene haplotype strongly reflects the geographic origin and identifies subgroups with a homogenous genetic background. Thus the observed effects might result more from differences in as yet unidentified determinants in the genetic background than from the direct linkage with differences in the beta-globin gene locus.
 ...
PMID:Acute clinical events in 299 homozygous sickle cell patients living in France. French Study Group on Sickle Cell Disease. 1100 50

Patients with sickle cell disease have been documented to be particularly susceptible to osteoarticular infections. Controversy exists concerning the bacteriology, etiology, and clinical presentation in differentiating osteoarticular infections from bone infarct. We retrospectively reviewed all cases from our institution over the past 22 years of osteoarticular infections in children who carry the diagnosis of sickle cell disease. Two thousand consecutive patient charts of children enrolled in the Pediatric Sickle Cell Clinic of our institution between 1973 and 1995 were evaluated. There were 14 cases of bone or joint infections (10 osteomyelitis, four septic arthritis). There was one case of multicentric osteomyelitis and one case of meningitis complicating the septic arthritis. There were nine male and five female patients with ages ranging from 6 months to 17 years (mean, 8.0). All patients were noted to have hemoglobin SS. The predominant presenting symptoms were pain (79% of cases) and swelling (71% of cases). The most frequent physical findings were fever >38.2 degrees C (71% of cases) and tenderness (86% of cases). Ninety-three percent of the children had a white blood count exceeding 15,000/mm3 (range, 7,900-32,300). Westergren sedimentation rates ranged from 14 to 89 mm/h with 93% of the children exceeding the normal value in our hospital. Cultures were positive in 75% of tissue biopsies, 58% of the blood cultures, and 70% of the bone or joint aspirates. The most common offending organism found in osteomyelitis was Salmonella (eight of 10 cases); however, no predominant organism found was identified in cases of septic arthritis. Radiographs and bone scans were of limited value in the differential diagnosis between osteoarticular infections and bone infarction. Early diagnosis and treatment of osteoarticular infections is key to satisfactory outcome. This study suggests that an ill-appearing patient with a fever >38.2 degrees C, pain, and swelling should prompt the physician to aspirate or biopsy the area and not rely on diagnostic studies that we found to be unreliable.
 ...
PMID:Retrospective review of osteoarticular infections in a pediatric sickle cell age group. 1100 53

Streptococcus pneumoniae causes approximately 3,300 cases of meningitis, 100,000 to 135,000 cases of pneumonia requiring hospitalization and 6 million cases of otitis media annually in the United States. Pneumococcal conjugate vaccine, approved in 2000 for use in the United States, was designed to cover the seven serotypes that account for about 80 percent of invasive infections in children younger than six years. This vaccine demonstrated 100 percent efficacy against invasive pneumococcal disease in the primary analysis of a large randomized, double-blind, controlled trial. In the follow-up analysis, performed eight months after the trial ended, efficacy against invasive disease was found to be 94 percent for the included serotypes. When initiated during infancy, the four-dose vaccination schedule is set at two, four, six and 12 to 15 months of age. The American Academy of Family Physicians recommends routine vaccination of infants, catch-up vaccination of children younger than 24 months and catch-up vaccination of children 24 to 59 months of age with high-risk medical conditions such as sickle cell disease and congenital heart disease.
 ...
PMID:Pneumococcal conjugate vaccine for young children. 1138 8

Sickle-cell disease (SCD) is associated with frequent and often severe infections as a result of immune function impairment and functional asplenia. Also, infection can trigger a vasoocclusive crisis. Pneumonococcal bacteremia and meningitis due to S. pneumoniae are often lethal and justify the penicillin prophylaxis, which has provided a dramatic decrease in early mortality bacterial pneumonia is common in patients younger than four years, with most cases being due to S. pneumoniae, H. influenzae, Mycoplasma pneumoniae, Chlamydia pneumoniae. Acute chest syndrome is both a difficult differential diagnosis and a common concomitant of bacterial pneumonia, because they are often intricated. Osteomyelitis is generally due to Salmonella, most often S. enteritidis. Multiple foci are common and treatment is difficult, with some patients developing chronic osteomyelitis with sequestration. Osteomyelitis is less frequent in developed countries and must been differentiated with bone infarction by use of bone scintigraphy. Parvovirus B19 infection causes acute erythroblastopenias. Malaria does not result in cerebral malaria, but can lead to severe anaemia or vasoocclusive crisis, and should therefore be effectively prevented. Antimicrobials are generally selected for efficacy against pneumococci (septicemia, meningitis), Salmonella (osteomyelitis, meningitis), and M. pneumoniae (pneumonia). Prophylactic therapy is of paramount importance and relies on long-term or lifelong penicillin therapy started at three months of age and no closely-spaced immunizations, most notably against peumococci, hepatitis B virus, S. typhi and H. influenzae. Resistant pneumococcal strains have not been reported to cause prophylactic treatment failures. New conjugated pneumococcal vaccines are effective in protecting very young infants and should therefore be used in sickle cell patients.
 ...
PMID:[Severe infections in children with sickle cell disease: clinical aspects and prevention]. 1158 20

Sickle cell anaemia (SCA) predisposes a child to infections for various reasons, including increased bone marrow turnover, poor perfusion and functional asplenia leading to decreased opsonisation of polysaccharide encapsulated organisms. Bacteria and viruses that most frequently cause serious infections in children with sickle cell disease are Streptococcus pneumoniae, Haemophilus influenzae type b, Salmonella spp., Escherichia coli, Staphylococcus aureus, Mycoplasma pneumoniae, Chlamydia pneumoniae, parvovirus B19 and hepatitis A, B and C viruses. Penicillin prophylaxis has decreased the incidence of infection-related morbidity and mortality significantly in children with SCA. Children <3 years of age are administered oral penicillin 125mg twice daily, and the dose is increased to 250mg twice daily for the >3 to 5 year age group. Adherence to the penicillin prophylactic regimen is recommended for children with SCA who are >5 years of age. For children with SCA who have recurrent invasive pneumococcal infections, an effort is made to keep the child on penicillin prophylaxis indefinitely. The administration of various childhood vaccines has also made an appreciable impact on the overall morbidity and mortality associated with infection in children with SCA. The administration of the heptavalent conjugate pneumococcal vaccine (PCV7) has provided control of invasive pneumococcal infections, and the prophylactic use of the H. influenzae type b conjugate vaccine has reduced the incidence of septicaemia and meningitis caused by this organism. Other vaccines used prophylactically in children with SCA include hepatitis A and B, and vaccines against influenza and varicella viruses. The immediate administration of intravenous antibacterials, after appropriate blood and urine cultures, is of great importance in the treatment of the febrile child with SCA. Ceftriaxone and cefotaxime have been recommended for the treatment of septic episodes in SCA associated with S. pneumoniae, Haemophilus and Salmonella spp. Infection with Yersinia enterocolitica may be treated with cefotaxime or an aminoglycoside. The prevalence of Helicobacter pylori infection in SCA is unknown. Effective therapies include metronidazole, tetracycline or amoxicillin. Parvovirus infections require supportive care and specific antiviral therapy is not indicated. The judicious use of antimicrobials is encouraged in view of the worldwide emergence of multidrug-resistant strains. The long term sequelae associated with infections in children with SCA can be decreased with the implementation of immunisation programmes and effective and prompt treatment with appropriate antibacterials.
 ...
PMID:Prevention and management of infection in children with sickle cell anaemia. 1173 65

The purpose of our study was to determine the usefulness of echo-planar diffusion-weighted imaging (EPDI) in the evaluation of watershed hypoxic-ischemic brain injury in pediatric patients. Eighteen patients ranging in age from 3 weeks to 12 years were evaluated for evidence of ischemic/infarction changes on conventional MR and EPDI. Included in the study group were five patients with sickle cell disease, four with congenital heart disease, four with hypotensive episodes with various etiologies, three with sepsis, and two with encephalitis or meningitis. Patients were examined 2 h to 6 days after the initial insult, with follow-up studies in four patients at 1 to 62 days after the initial examination. After conventional MR imaging (T1, FSE T2, and FLAIR), diffusion-weighted MR imaging was performed using high-speed, single-shot EP techniques with TR 6000, TE 144, matrix 96 x 128, FOV 23.3 x 31 and five b values of 0, 160, 360, 640, and 1,000 s/mm2. EPDI demonstrated abnormally increased signal in watershed ischemic/infarction zones in all initial cases. Apparent diffusion coefficients (ADC) were obtained in 59 lesions. When compared with radiographically normal (on EPDI) contralateral brain parenchyma, 45 demonstrated a relatively decreased ADC, while eight had normal ( +/- 10%) and six had increased ADC. In four cases, signal abnormalities on EPDI were not seen or exceeded that seen with conventional MR imaging. In the remaining cases, signal abnormalities were obvious on EPDI and more subtle on conventional MR imaging. Follow-up studies demonstrated resolution of abnormal EPDI signal with persistent abnormalities on conventional imaging in some cases, while others revealed an increase in size or number of EPDI signal abnormalities, suggesting ongoing acute ischemic/infarctive changes. EPDI is a rapid, sensitive technique for detecting watershed ischemic/infarction changes in pediatric patients with hypoperfusion episodes, at times before such changes are apparent on conventional MR images and/or are clinically apparent.
 ...
PMID:Diffusion-weighted imaging in the evaluation of watershed hypoxic-ischemic brain injury in pediatric patients. 1176 Jul 94

Despite systematic antibiotic therapy, severe infections (septicemia, meningitis, or osteomyelitis) are a major cause of mortality and morbidity in children with sickle cell disease (SCD). In this study, we explored the possibility that polymorphism at the human leukocyte antigen (HLA) locus might constitute an immunogenetic modifying factor to the intrinsic susceptibility to infection in patients with SCD. A cohort of 80 SCD patients living in Paris, 43 with at least one major infectious complication and 37 without infections, were typed for HLA class II loci by polymerase chain reaction-sequence-specific primers (PCR-SSP). We found that significantly more patients without infections carry the HLA class II DRB1*15 specificity than did patients with infections (21.6% in the first group, versus 4.7% in the second group; chi(2) = 10.47, p(c) = 0.01), supporting a protective effect of this allele. Conversely, significantly more patients were found to carry the DQB1*03 specificity within the group of severe infections, supporting a negative effect (34.9% versus 12.2%, chi(2) = 9.41, p(c) = 0.01). These findings suggest a direct involvement of HLA polymorphism in the development of major infections in SCD. Together with previous data on polymorphism of the Fc receptor and of the mannose-binding lectin, they provide evidence for a polygenic immunomodulation of the constitutively increased infectious risk in SCD.
 ...
PMID:Infectious complications in sickle cell disease are influenced by HLA class II alleles. 1187 37

Streptococcus pneumoniae is the most frequent cause of otitis media, sinusitis, and pneumonia in children. It is also one of the most common causes of invasive bacterial infections in children including bacteremia and meningitis. One of the current issues regarding S. pneumoniae is the emergence of pneumococcal strains resistant to penicillin and other antibiotics. Children less than two years of age suffer an increased incidence of invasive pneumococcal disease but fail to respond to the 23-valent polysaccharide vaccine because of the immaturity of the T-cell independent immune function. Covalently conjugating the polysaccharide antigen to a carrier protein improves the immune response by permitting the host to utilize a T-cell dependent immune response that is adequately mature in children less than two years of age. Immunogenicity studies of the currently licensed heptavalent conjugated polysaccharide vaccine, (Prevnar, marketed by Wyeth Lederle Vaccines) demonstrated that infants vaccinated with three doses 2 months apart at 2, 4, and 6 months of age successfully developed antibodies to all 7 serotypes; booster doses at 12-15 months demonstrated an amnestic response for each serotype. Immunogenicity studies have similarly demonstrated successful responses in children with sickle cell disease and human immunodeficiency virus infection. An efficacy trial involving nearly 38,000 subjects demonstrated the vaccine's effectiveness in healthy children against invasive pneumococcal disease as well as against pneumonia and otitis media. Currently the US Advisory Committee on Immunization Practices (ACIP) recommends that all infants and children under 24 months of age receive the vaccine. The ACIP recommends that infants receive the vaccine routinely at 2, 4 and 6 months with a fourth dose at 12 to 15 months of age. Infants may receive the first dose as early as 6 weeks of age. The vaccine is also indicated for children 24 to 59 months of age who are at high risk for pneumococcal infection. Adverse events include local reactions in the first two days following vaccination such as approximately 10% reporting erythema, 10% induration, and 20% tenderness. Fever of 38 degrees C or higher occurred in 15% to 25% of children in the first two days following vaccination. Follow-up studies should address important questions regarding the use of pneumococcal conjugate vaccine and other age groups.
 ...
PMID:The pneumococcal conjugate vaccine. 1213 65

The purpose of this study was to determine the age-related risks, disease-specific risks, and characteristics of serious pneumococcal infections in children with sickle cell disease (SCD) while penicillin prophylaxis was standard. The clinical experiences of three pediatric sickle cell programs spanning January 1, 1992, to May 31, 1998, were combined. Data were collected regarding the patients followed up and the characteristics of bacteremia and meningitis cases. Forty-seven pneumococcal infections (44 bacteremia, 3 meningitis) among 40 patients with SCD were observed. Forty infections occurred in children with homozygous hemoglobin S (SS) during 4108 patient-years at a median age of 22 months; 7 occurred in double heterozygous hemoglobin SC (SC) children during 1777 patient-years at a median age of 23 months. Ten infections occurred among 9 SS children 5 years or older. Most children in whom infections developed were reportedly taking prophylactic penicillin and when older than 24 months old had received Pneumovax (Merck & Co., Inc., West Point, PA, U.S.A. The following pneumococcal serotypes were identified in 15 cases studied: 6A, 6B, 9V, 14, 15B, 18B, 18F, 19F, and 23F. Infections resulted in five deaths and two strokes. The observed severe pneumococcal infection rate in SS children younger than 5 years was less than that reported before penicillin prophylaxis, supporting routine penicillin prophylaxis in this specific population. The optimal duration of penicillin prophylaxis in older children with SCD remains unknown. The administration of 7-valent Prevnar (Wyeth Lederle Vaccines, Philadelphia, PA, U.S.A.) to children younger than 24 months old with SCD should be beneficial, based on the serotype data.
 ...
PMID:Streptococcus pneumoniae sepsis and meningitis during the penicillin prophylaxis era in children with sickle cell disease. 1221 95

Children with sickle cell anemia are more exposed to infection than healthy children. Indeed, infections are the major cause of morbidity and mortality in children with sickle cell anemia, especially those aged 6 months to 5 years. Phagocytosis is reduced in these children. Polynuclear neutrophils reveal various poorly understood irregularities and are associated with a reduction of phagocytic power: zinc deficiency, reduced post-phagocytic oxidative metabolism, and a prevalence of neutrophils not forming red sheep-like globule carriers of immunoglobulin H. The power of the antibody which renders germs susceptible to phagocytosis in the serum is reduced in sickle cell patients. This may be tied to a disorder in the alternate complementary route with reduction of C3 and properdin. Sequestration of sickle cell-shaped red blood cells, splenic congestion, and short circuits of important functional territories contribute to spleen dysfunction, which occurs early. Common pathogens attacking sickle cell patients are pneumococci, salmonella species, and Haemophilus influenzae. They cause very grave infections (e.g., septicemia and purulent meningitis). Prevention of infections dwells on three perspectives: early screening for sickle cell anemia and for spleen dysfunction, preventive penicillin therapy, and vaccination. In Benin, vaccination is the only means to prevent infections. Essential vaccinations for children with sickle cell anemia include BCG, diphtheria-pertussis-tetanus, polio, and Rouvax. Strongly recommended vaccinations are Pneumovax 23, HEVAC B, TAB, vaccine against H. influenzae, and vaccine against mumps. A vaccine calendar for children with sickle cell anemia guides health workers when they must administer the vaccines and their boosters over a six year period. It is not yet universal in health facilities in Benin. A short- and long-term evaluation of the calendar's efficacy would allow one to appreciate its real impact on reducing morbidity and mortality in children with sickle cell anemia.
 ...
PMID:[Prevention of infectious diseases in the drepanocytic child]. 1229 Jan 82


<< Previous 1 2 3 4 5 6 7 8 9 Next >>