Mycoplasma pneumoniae pneumonia is usually a self-limited respiratory tract infection. It is well known that a transient elevation of the levels of anti-I, which reacts with the I antigen of the I-i system of the human RBC, occurs in the course of M pneumoniae infections, but there has been no report, to our knowledge, that anti-M specific for the M antigen of the M-N system of the human RBC has developed during its course.
We describe a 6-year-old girl who needed blood transfusions for hemorrhagic shock caused by postinfectious thrombocytopenia and was found to have high titers of anti-M at the time of admission to hospital.
Report of a Case.—A 6-year-old girl was admitted to our hospital because of fever, malaise, and productive cough of ten days' duration. There was no history of transfusions. On admission, a roentgenogram of the chest disclosed an infiltrate in the left lower lobe.