Spectrum of Changes in RBC Indices and Histograms in Blood from Subjects with Cold Antibodies.

Cold antibodies are mostly immunoglobulin M, which interact with red cell antigens at lower temperatures (<37°C). The analysis of samples from subjects with cold antibodies in automated haematology analysers may show abnormal Red Blood Corpuscles (RBC) indices and changes in histogram. High Mean Corpuscular Haemoglobin (MCH) and Mean Haemoglobin Concentration (MCHC) along with plateau effect beyond 110fl at Upper Discriminator (RU) end of RBC histogram are good indicators of presence of cold antibodies in plasma. Cold antibodies in plasma must be considered while reporting the peripheral smear in presence of plateau effect beyond 110fl at RU end of RBC histogram.