Serological investigation and clinical significance of high-titer, low-avidity (HTLA) antibodies.

High-titer, low-avidity (HTLA) antibodies are frequently described as "reactive weakly by the antiglobulin test." These antibodies include: anti-Chido (Cha) and anti-Rodgers (Rga), and anti-Cost-Stirling (Csa) and anti-York (Yka), anti-Knops (Kna) and anti-McCoy (McCa), and anti-John Milton Hagen (JMH), the majority of which are directed at high-incidence red cell antigens. The classic HTLA antibodies are thought to be incapable of fixing complement or causing in vitro hemolysis. Present data indicate that these antibodies do not cause either increased red cell destruction when incompatible blood is transfused or hemolytic disease of the newborn. Special serological techniques can be used to differentiate the antibodies within the HTLA classification from antibodies not of an HTLA nature.