Circulating immune complexes in patients with advanced tuberculosis and their association with autoantibodies and reduced CD4 + lymphocytes

We investigated the presence of circulating immune complexes (CICs) in serum from tuberculosis (TB) patients with different degrees of pulmonary involvement. Patients were classified into four groups according to the extent of lung involvement: mild (N = 9), moderate (N = 12), moderate plus (N = 16), and severe cases (N = 10). A search for CICs by the 3.5 percent PEG precipitation test showed that the CIC values of patients with the moderate plus or severe form of pulmonary TB were significantly higher compared to healthy controls and to mild and moderate cases (P<0.01 and P<0.001, respectively). Further analysis demonstrated that increased CIC levels were associated with increased autoantibody production, since this abnormality was more prevalent in patients with advanced disease (P<0.01), who also showed a significant reduction of CD4+ T. lymphocytes. The immunoregulatory and pathogenetic implications of these findings are discussed

Depressed adjuvant arthritis in rats transferred with spleen cells from Trypanosoma cruzi-infected syngeneic donors

In the present we investigated whether the attenuating effect of chronica Trypanosoma cruzi (Tc) infection on adjuvant arthritis (AA) in the rat could be transferred to naive recipients. Transfer of whole spleen cells, but not of serum, from Tc-infected rats reduced AA (x ñ SEM: 11 ñ 0.5) in recipient animals (control values, x ñ SEM: 19 ñ 0.7). Transfer of a T-cell enriched subpopulation from spleen cells of Tc-infected rats (obtained by filtration through a nylon column) resulted in a similar attenuationb of AA (x ñ SEM: 7.5 ñ 2.2). The arthritic response of rats intraperitoneally inoculated with 2 x 10**5 Tc 48h before induction did not differ from that observed in controls. Neither parasites nor specific antibodies were observed in suckling mice inoculated with serum or cell suspensions employed in transfer experiments. Consequently, the depressive effect on AA could not be directly attributed to Tc per se. We hypothesize that a homeostatic immunosuppressor mechanism may be responsible for this phenomenon

Inmunopatologia de la lepra / Immunopathology of leprosy

Se comentan los estudios en convivientes íntimos de enfermos de Lepra, donde se observó una relación inversa entre grado y tiempo de exposición al Mycobacterium leprae (MI) y la magnitud de la respuesta inmune in vivo hacia el bacilo (reacción de Mitsuda); esta variable por otro lado, se halla influenciada por un importante grado de determinación genética. En un modelo murino experimental, la artritis por adyuvante, también se comprobó que el tratamiento con MI inducia una población de células esplénicas supresoras, con actividad regulatoria sobre la respuesta inmune celular. Se plantean además, las posible alteraciones inmunorregulatorias involucradas con la excesiva respuesta humoral que sirve de sustrato para la generación del episodio de eritema nudoso leproso (ENL)