Cold agglutinins are autoantibodies and are often present in the sera of healthy individuals. They assume importance when the thermal reactivity of these antibodies approaches body temperature. This communication describes a case of cold hemagglutinin disease with Mycoplasma pneumoniae infection detected during routine laboratory investigations. The patient was managed conservatively.

A microagglutination method utilizing stained antigen for detecting and measuring serum agglutinins against Francisella tularensis is described. The microagglutination and standard tube agglutination techniques were demonstrated to be comparable in sensitivity and specificity. Advantages of the micro method are rapidity and ease of performance, economy of reagents and, in particular, ease of in...

The fetal antigen i has been demonstrated by indirect immunofluorescence on cord erythrocytes and placental trophoblast. A patient with disseminated choriocarcinoma developed high-tire anti-i cold agglutinins, and minor elevation of anti-i titres was seen in four out of six further patients with treated choriocarcinoma. In normal pregnant women, 6% showed similar increases in anti-i titres.

CONTENTS INTRODUCTION ..... . . ...... ..... ......... .............. . . . ...... .......................... ......................... . . . ... ... 147 ANTIGEN SHARING BETWEEN MICROBES AND THEIR ANIMAL HOSTS .... ... ..... .. 148 Mycoplasma ............................................................. ....... ... ............... ........ ... ......... .. .. 148 Bacteria .........................