Hémoglobines anormales rares

Hemoglobinopathies are genetic disorders of hemoglobin and are the most common inherited disorder in humans. The hemoglobin molecule is composed of four separate polypeptide chains, two alpha and two beta, as well as four iron-bearing heme groups that bind oxygen. The alpha chains are coded for by two similar genes on chromosome 16, the beta chains being coded by a single gene on chromosome 11. If most commonly, there is no structural or functional consequence, alteration of a single amino acid may have dramatic clinical consequences. This is the case with several unstable hemoglobins with high oxygen affinity or M hemoglobins. Depending on the molecular defect, unstable hemoglobins may induce hemolysis in vivo, hemoglobins with high affinity may induce compensatory erythrocytosis and hemoglobin M always cause pseudo cyanosis more or less visible. Generally, the molecular defect explains the pathology: unstable hemoglobins are frequently due to mutations in the heme pocket, hemoglobins with high affinity to mutations that alter the transition in the three-dimensional hemoglobin conformation that accompanies the removal of oxygen and M hemoglobins to mutations that stabilize the heme-iron in its oxidized form. Diagnosis of these rare hemoglobin variants is mandatory for adequate treatment, or in the case of hemoglobin M and hemoglobin with high affinity to prevent inappropriate investigations due to the mistaken impression that the patient has a cardiac, pulmonary or neoplastic disorder. © 2004 Elsevier SAS. Tous droits réservés.Editions ElsevierSCOPUS: sh.jinfo:eu-repo/semantics/publishe

Association of baseline hematoma and edema volumes with one-year outcome and long-term survival after spontaneous intracerebral hemorrhage: A community-based inception cohort study

Background Hospital-based studies have reported variable associations between outcome after spontaneous intracerebral hemorrhage and peri-hematomal edema volume. Aims In a community-based study, we aimed to investigate the existence, strength, direction, and independence of associations between intracerebral hemorrhage and peri-hematomal edema volumes on diagnostic brain CT and one-year functional outcome and long-term survival. Methods We identified all adults, resident in Lothian, diagnosed with first-ever, symptomatic spontaneous intracerebral hemorrhage between June 2010 and May 2013 in a community-based, prospective inception cohort study. We defined regions of interest manually and used a semi-automated approach to measure intracerebral hemorrhage volume, peri-hematomal edema volume, and the sum of these measurements (total lesion volume) on first diagnostic brain CT performed at ≤3 days after symptom onset. The primary outcome was death or dependence (scores 3–6 on the modified Rankin Scale) at one-year after intracerebral hemorrhage. Results Two hundred ninety-two (85%) of 342 patients (median age 77.5 y, IQR 68–83, 186 (54%) female, median time from onset to CT 6.5 h (IQR 2.9–21.7)) were dead or dependent one year after intracerebral hemorrhage. Peri-hematomal edema and intracerebral hemorrhage volumes were colinear ( R2 = 0.77). In models using both intracerebral hemorrhage and peri-hematomal edema, 10 mL increments in intracerebral hemorrhage (adjusted odds ratio (aOR) 1.72 (95% CI 1.08–2.87); p = 0.029) but not peri-hematomal edema volume (aOR 0.92 (0.63–1.45); p = 0.69) were independently associated with one-year death or dependence. 10 mL increments in total lesion volume were independently associated with one-year death or dependence (aOR 1.24 (1.11–1.42); p = 0.0004). Conclusion Total volume of intracerebral hemorrhage and peri-hematomal edema, and intracerebral hemorrhage volume alone on diagnostic brain CT, undertaken at three days or sooner, are independently associated with death or dependence one-year after intracerebral hemorrhage, but peri-hematomal edema volume is not. Data access statement Anonymized summary data may be requested from the corresponding author. </jats:sec