Autoimmune hemolytic anemia caused by IgG lambda-monotypic cold agglutinins of anti-Pr specificity after rubella infection

BACKGROUND: In postinfection cold agglutinin (CA) disease, a relation betwe en CA specificity and the underlying infectious agent has been observed. Th e induction of anti-I by Mycoplasma pneumoniae and that of anti-I by EBV ar e well-established examples. CASE REPORT: A 5-year-old boy developed severe hemolytic anemia after serol ogically ascertained rubella infection. Hemolysis was caused by high-titer CAs, which were analyzed by absorption and elution with sialidase-treated R BCs and hemagglutination-inhibition experiments. RESULTS: After elimination of normal anti-I and anti-T, the predominant CA was found to be an IgG lambda autoantibody with anti-Pr, specificity. CONCLUSION: This case seems to be of interest because it is the first repor t of severe CA-induced hemolysis after rubella infection, it is the first d escription of an IgG lambda -monotypic CA, and, along with previous case re ports (three established and three suspected cases), it indicates a relatio nship between rubella infection and the CA specificity anti-Pr.