Int Conf AIDS. 1994 Aug 7-12;10(2):136 (abstract no. PB0556). Unique
OBJECTIVE: In previous investigations, we demonstrated that clinical
severity of R. equi pneumonia in AIDS patients was correlated with lower
specific antibody response. The aim of this study was to further
evaluate the humoral immune response to R. equi infection in AIDS
patients as well as in healthy subjects. Moreover, the immunoreactivity
of human intravenous immunoglobulin (IVIG) to R. equi antigens was also
examined. METHODS: Specific antibody response to whole cell antigens of
R. equi was analyzed by enhanced chemiluminescence immunoblotting in 22
serum samples from 5 AIDS patients with R. equi pneumonia, in 20 from
AIDS patients without R. equi infection, in 30 from healthy controls and
in a commercial lot of IVIG (Ig VENA, lot 192, Sclavo, Italy). RESULTS:
The sera from 3 AIDS patients, who fully recovered from R. equi
pneumonia, had a stronger antibody response to R. equi antigens than
that found in AIDS patients without R. equi infection and healthy
controls. Conversely, the sera from 2 patients with severe R. equi
infection showed little or no reaction with R. equi antigens. Finally,
immunoblotting experiments showed that IVIG exhibited an intense
reactivity with all antigenic components of R. equi. DISCUSSION AND
CONCLUSIONS: Our findings suggest that: i) R. equi antibodies naturally
occur in humans; ii) humoral immunity may play an important role both in
the protection against and recovery from R. equi infection in AIDS
patients. Further studies are in progress to investigate the value of
IVIG or other immunotherapies in AIDS patients with R. equi infection.
Acquired Immunodeficiency Syndrome/COMPLICATIONS/IMMUNOLOGY
Actinomycetales Infections/COMPLICATIONS/*IMMUNOLOGY/THERAPY
Antibodies, Bacterial/*BIOSYNTHESIS/BLOOD Antigens, Bacterial
AIDS-Related Opportunistic Infections/COMPLICATIONS/*IMMUNOLOGY/
THERAPY Human Immunity, Natural Immunoblotting Immunoglobulins,
Intravenous/PHARMACOLOGY Immunotherapy In Vitro *Rhodococcus
equi/IMMUNOLOGY ABSTRACT