ABSTRACT
BACKGROUND: Anti-M is frequently observed as a naturally occurring antibody of little clinical significance. Naturally occurring anti-M is often found in children although the specific triggers of production, persistence, and evanescence of anti-M have yet to be elucidated. METHODS: In a retrospective, multicenter, nationwide cohort survey conducted from 2001 to 2015, alloantibody screening was performed before and after transfusion in 18,944 recipients younger than 20 years. Recipients were categorized into six cohorts based on their age at transfusion; within and among these cohorts, allo-anti-M was analyzed in regard to its production, persistence, and evanescence. RESULTS: In 44 patients, anti-M detected before and/or after transfusion was an age-related phenomenon, with a median age of 2 years and an interquartile range of 1-3 years; anti-M was most frequently detected in a cohort of children 1 to <5 years (0.77%, 31 of 4035). At least five patients were presumed to have concurrent infections. Among 1575 adolescents/young adults (15 to <20 years), no anti-M was detected. Of 29 patients with anti-M prior to transfusion, the antibody fell to undetectable levels in 17 recipients (89.5%, of whom at least 13 received only M-negative red cells) after anywhere from 5 days to 5.8 years; anti-M persisted in 2, and was not tested in 10. Only 15 recipients (0.08%) produced new anti-M after transfusion. CONCLUSION: Naturally occurring anti-M is a phenomenon of younger ages, predominantly between 1 and 3 years. After transfusion, it often falls to undetectable levels.
Subject(s)
Erythrocyte Transfusion , Isoantibodies/immunology , MNSs Blood-Group System/immunology , Child, Preschool , Erythrocyte Transfusion/adverse effects , Female , Humans , Infant , Isoantibodies/blood , MNSs Blood-Group System/blood , Male , Retrospective StudiesABSTRACT
Studies examining risk factors associated with vasovagal reactions (VVRs) during autologous blood donations, especially in younger subjects, have been limited. The aim of the present study was to define risk factors for VVRs during preoperative autologous blood donation in patients, including those younger than 18 years old. We retrospectively analyzed 4192 autologous, preoperative blood donations between 2007 and 2015 at Okayama University Hospital. Eighty-seven (2.08%) of the patients experienced VVRs. VVRs occurred approximately three times as often in patients 0-17 years old (16/320, 5.0%) than in patients 18 years and older (71/3872, 1.8%). In particular, VVRs occurred more frequently in those 10-13 years old, and decreased with older age (P = 0.006). In a univariate analysis, younger age, lower body mass index, lower systolic blood pressure, lower body weight, lower total blood volume, female gender, first-time collection, and higher heart rate were associated with a higher incidence of VVRs. In a multivariate analysis, lower systolic blood pressure (P < 0.001), higher heart rate (P = 0.007), and first-time collection (P = 0.015), remained independent predictors of VVRs. These results emphasize the need for careful attention during blood collection.
Subject(s)
Blood Donors , Blood Transfusion, Autologous , Preoperative Care , Syncope, Vasovagal/epidemiology , Adolescent , Adult , Age Factors , Aged , Aged, 80 and over , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Middle Aged , Risk Factors , Syncope, Vasovagal/etiologyABSTRACT
Anti-A and/or anti-B antibodies synthesized by lymphoid tissues contained in ABO-mismatched solid organ grafts have been reported to cause hemolytic anemia, but not suppressed red blood cell production. A case of living-donor lobar lung transplantation is presented in which suppression of erythropoiesis was associated with ABO mismatched organ transplantation.
