Multiple or uncommon red cell alloantibodies in women: association with autoimmune disease.

BACKGROUND: Patients with multiple or uncommon red cell (RBC) alloantibodies require special efforts in the blood bank. This study investigated whether such persons had other immune-related conditions that might help to explain or predict their propensity for RBC antibody formation. STUDY DESIGN AND METHODS: Charts were retrospectively reviewed of 29 men and 83 women with multiple (> or = 3) RBC antibodies of potential clinical significance, uncommon RBC antibodies (anti-e, -Kpb, -Jkb, -Fyb, -S, -U, -Yta, -Dib, -Ata), or both. The clinical features in 43 women with multiple antibodies were compared to those in two equal-sized control cohorts of women matched for transfusion-related diagnoses, but having either one RBC antibody or none. RESULTS: Women with uncommon RBC antibodies had a 33-percent (18/54) prevalence of autoimmune disease. Twenty-eight percent of the 43 women with multiple antibodies had autoimmune disease, compared to 14 percent of women in the cohort with one RBC antibody (p = 0.09) and 7 percent of those in the cohort without RBC antibodies (p = 0.01). Only one of the 29 men had autoimmune disease. CONCLUSION: Autoimmune disease is a common underlying factor in women who make multiple or uncommon RBC alloantibodies of potential clinical significance.

Long-term follow-up testing of red cell alloantibodies.

BACKGROUND: In previous studies, 29 to 34 percent of potentially hemolytic red cell antibodies were not detected after short-term follow-up. STUDY DESIGN AND METHODS: To examine long-term detection, records were reviewed for 44 consecutive patients who were tested more than 5 years after their potentially hemolytic red cell antibodies were first identified in this hospital. RESULTS: After 5 to 10 years, 14 (39%) of 36 Rh, Kell, and Duffy system antibodies were not detected on at least one occasion. Twenty-two other such antibodies were sought again after more than 10 years; 10 (45%) were not detected. When restimulation by pregnancy was excluded, these rates were 42 and 48 percent, respectively. CONCLUSION: Clinically significant red cell antibody formation is probably more common than previously realized, because nearly half of these antibodies are undetected after long-term follow-up.