title: Characterization of direct antiglobulin test-negative autoimmune hemolytic anemia: a study of 154 cases.
abstract: Direct antiglobulin test (DAT)-negative (DAT-)autoimmune hemolytic anemia (AIHA) is empirically thought to show the same clinical conditions as DAT-positive (DAT+)AIHA, with the exception of an adequate amount of red blood cell (RBC)-bound immunoglobulin (Ig)G. We investigated the clinical characteristics of DAT-AIHA in comparison with DAT+AIHA. Of the 582 patients referred to our laboratory with undiagnosed hemolytic anemia, AIHA was clinically diagnosed in 216 patients (DAT-AIHA, n = 154; DAT+AIHA, n = 62). The percentage of reticulocytes, mean corpuscular volume, RBC-IgG levels, white blood cell count, and total protein (TP) levels were significantly higher in patients with DAT+AIHA than patients with DAT-AIHA. The hemoglobin level was significantly lower in patients with DAT+AIHA. No significant differences between patients with DAT-AIHA and DAT+AIHA existed with respect to age, gender, idiopathic/secondary nature, complications such as Evans syndrome, effectiveness of steroid treatment, or survival rate at 1 year following diagnosis. Patients with DAT-AIHA required significantly lower doses of steroids for maintenance therapy. Based on multivariate analysis of idiopathic DAT-AIHA (n = 110), TP and Evans syndrome were associated with the effectiveness of steroids (adjusted odds ratio [aOR], 1.36/[0.1 g/dl]; 95% confidence interval [CI], 1.01-1.84) and survival at the 1-year follow-up (aOR, 0.1; 95% CI, 0.01-0.88). Our results indicate that patients with DAT-AIHA generally suffer milder anemia and hemolysis than patients with DAT+AIHA, respond equally well to steroids, and have comparable survival at 1-year.
authors.affiliation: Center for Community Medicine, Jichi Medical University, Shimotsuke, Tochigi, Japan. kmskt@jichi.ac.jp
authors.forename: Toyomi
authors.initials: T
authors.lastname: Kamesaki
authors.forename: Tomonori
authors.initials: T
authors.lastname: Toyotsuji
authors.forename: Eiji
authors.initials: E
authors.lastname: Kajii
mesh_terms: D000328:Adult; D000368:Aged; D000744:Anemia, Hemolytic, Autoimmune / Q000097:blood / Q000188:drug therapy* / Q000276:immunology* / Q000503:physiopathology; D001798:Blood Proteins / Q000032:analysis; D016022:Case-Control Studies; D003298:Coombs Test; D004909:Erythrocyte Indices; D004912:Erythrocytes / Q000378:metabolism; D005260:Female; D005500:Follow-Up Studies; D006461:Hemolysis; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis / Q000378:metabolism; D060046:Maintenance Chemotherapy; D008297:Male; D008875:Middle Aged; D017701:Reticulocyte Count; D012720:Severity of Illness Index; D013256:Steroids / Q000008:administration & dosage / Q000627:therapeutic use*; D016019:Survival Analysis
chemical_list: D001798:Blood Proteins; D007074:Immunoglobulin G; D013256:Steroids