The Relationship of Commonly Encountered Saprophytic and Pathogenic Fungi to Human A and B Blood Group Antigens**From the Department of Medicine, Division of Dermatology, University of California, The Center for the Health Sciences, Los Angeles 24, California and the Medical Service, Veterans Administration Center, General Medical and Surgical Hospital, Los Angeles 25, California

Serosurvey of Leptospira agglutinins among railway employees in the National Railway Compartments of Bologna and Venice

An epidemiological investigation was performed to evaluate the prevalence of anti-leptospiral agglutinins within a selected population: the railway workers of the Italian Railway Compartments of Bologna and Venice. Leptospira infection prevalence was found to be 10.38%, which represents the highest frequency ever reported in Italy. There was a significantly higher prevalence of agglutinins among the staff of the Railway Compartment of Venice. A clear prevalence of the bratislava serovar was registered, followed by the australis serovar and the icterohaemorrhagiae serovar. The influence of different kinds of railway work and that of supposed risk factors, such as hobbies and housing conditions, together with the influence of the ABO blood groups on the distribution of Leptospira agglutinins, are discussed.

The role of ABO blood groups and secretor status in host defences

Epidemiological studies on the associations between ABO blood group antigens, secretor status and susceptibility to infectious agents are summarized. Evidence for association of non-secretion with some autoimmune diseases for which infectious aetiologies have been proposed is also given. Several hypotheses are proposed to explain the host-parasite interactions underlying the epidemiological observations, and evidence to support or refute them is presented.

Association of ABO blood group and outcome of coccidioidal infection

Dissemination of fungal infection due to Coccidioides immitis has been previously shown to be related to hereditary factors. Two associations reported to date are race (e.g., Filipino and black ancestry) and HLA histocompatibility type (HLA-19). In the present study of 105 patients a significant association of blood group B and dissemination is demonstrated. C. immitis is known to possess antigens with blood group A activity. Previous epidemiologic studies have also shown HLA-A9 and blood group B are both more common in persons of black and Filipino ancestry. Further studies are needed to define whether these are independent variables, and may define subgroups at particularly high risk following coccidioidal infection.

Immunological cross-reactivity between a glycoprotein isolated from Trichophyton mentagrophytes and human isoantigen A

A glycoprotein isolated from the cell wall of Trichophyton mentagrophytes was assessed for its cross-reaction with human blood group isoantigens. Rabbit antiglycoprotein antibodies agglutinated human erythrocytes of blood groups A1 and A2, and precipitated Blood Group Substance A in agarose gels. Erythrocytes of blood group B were only slightly agglutinated, and O(Rho+) and O(Rho-) erythrocytes were not. Additionally, the glycoprotein was shown to specifically inhibit isoagglutination of erythrocytes of group A. Partial identity between the glycoprotein and a crude extract of the fungus was demonstrated by immunodiffusion. Analyses revealed the glycoprotein to be composed of approximately 17% protein and 80% carbohydrate. The glycoprotein was found by indirect immunofluorescence to be located in the mycelial cell wall. The possibility that cross-reacting antigens may lead to a chronic, spreading infection is discussed.