Liposomal amphotericin B and amphotericin B-deoxycholate show different immunoregulatory effects on human peripheral blood mononuclear cells

Conventional preparations of amphotericin B (AmB) at established therapeutic doses are known to increase nonspecific immune responses. It remains to be established whether higher doses of the less toxic liposomal preparation of AmB maintains a beneficial effect on the immune response to fungal infections. Examination of the effect of treatment of human peripheral blood mononuclear cells from healthy subjects with various doses of both liposomal AmB (L-AmB) and deoxycholate AmB (d-AmB) on proliferation, cell viability, and percentage of apoptosis demonstrated that, although both L-AmB and d-AmB at low doses significantly increased nonspecific proliferative responses, L-AmB, but not d-AmB, treatment maintained this beneficial effect at higher doses. High doses of d-AmB, but not L-AmB, resulted in significantly decreased cell viability and increased apoptosis. This study provides further evidence in healthy human subjects for choosing L-AmB over conventional preparations in the clinical treatment of fungal infections requiring systemic high-dose treatment with AmB.

Brucellosis in patients infected with the human immunodeficiency virus

Brucellosis has been described rarely in patients infected with HIV, despite the fact that eradication of intracellular brucellae is largely dependent on cell-mediated immunity. The characteristics of all patients with HIV infection and brucellosis seen in seven Spanish hospitals are reported. Since the beginning of the AIDS epidemic, 12 HIV-infected patients were diagnosed with brucellosis (8 with cultures positive for Brucella spp., 4 with high anti-Brucella antibody titers). Most patients were male and intravenous drug users. Eleven patients had no symptoms of HIV infection when first diagnosed with brucellosis and had relatively preserved cellular immunity (median CD4 + cell count 588, range 136-1006). There was a clear epidemiologic antecedent for acquisition of brucellosis in 11 patients. Clinical symptoms included fever, arthromyalgia, and sweating in all patients; four patients presented with focal disease. All patients had high agglutinin titers, and eight of nine had cultures positive for Brucella. Therapy with doxycycline and streptomycin was curative in all cases. Two patients experienced a recurrence of symptoms after initial treatment, although no microbiological relapses were documented after a median follow-up period of 18 months. HIV infection does not seem to increase the incidence of brucellosis. Since most cases occur in asymptomatic patients with relatively preserved immunity, the epidemiology, clinical presentation, diagnosis, response to therapy, and outcome are similar to those observed in non-HIV infected patients.

Multivariate model for predicting relapse in human brucellosis

Demographic, clinical, and laboratory data from 200 consecutive patients with acute brucellosis were analysed with univariate and multivariate methods to identify correlates of relapse. A risk score for predicting relapse was then calculated by using Cox proportional hazard model. The independent predictors of relapse were temperature of 38.3 degrees C or higher, positive blood cultures at baseline, and the duration of symptoms before treatment <10 days. Stratification according to the risk score demonstrated that rates of relapse were significantly different between risk groups (P<0.0001). The low-risk group had a 4.5% probability (6 of 135) of relapse at 12 months. In contrast, relapse was present in 15 of 47 patients in the medium-risk group (P<0.0017); and in 12 of 18 patients in the high-risk group (P<0.0001). This study provides a rational basis for estimating the risk of relapse in patients with acute brucellosis, and may be helpful in deciding what subjects might benefit from extra attention.

Doxycycline-rifampin versus doxycycline-streptomycin in treatment of human brucellosis due to Brucella melitensis. The GECMEI Group. Grupo de Estudio de Castilla-la Mancha de Enfermedades Infecciosas

Brucellosis is a common zoonosis in many parts of the world; the best regimen for the treatment of brucellosis has not been clearly determined. We have carried out a multicenter, open, controlled trial in five general hospitals in Spain to compare the efficacy and safety of doxycycline and rifampin (DR) versus doxycycline and streptomycin (DS) for the treatment of human brucellosis. The study included 194 ambulatory or hospitalized patients with acute brucellosis, without endocarditis or neurobrucellosis. The diagnostic criterion was isolation of Brucella species from blood or other tissues (n = 120) or a standard tube agglutination titer of 1/160 or more for anti-Brucella antibodies with compatible clinical findings (n = 74). Patients were randomly assigned to receive either 100 mg of doxycycline twice daily plus rifampin, 900 mg/day, in a single morning dose for 45 days (DR group) or the same dose of doxycycline for 45 days plus streptomycin, 1 g/day, intramuscularly for 14 days (DS group). A lack of therapeutic efficacy developed in 8 of the 100 patients in the DR group (8%) and in 2 of the 94 patients in the DS group (2%)(P = 0.10). Relapses occurred in 16 of the 100 patients in the DR group (16%) but in only 5 of the 94 patients in the DS group (5.3%) (P = 0.02). When relapse was considered in combination with initial lack of efficacy, 26 patients in the DR group (24%) and 7 patients in the DS group (7.45%) failed to respond to therapy (P = 0.0016). In general, therapy was well tolerated and only four patients (4%) in the DR group and two (2%) in the DS group had episodes of adverse effects necessitating discontinuation of treatment (P> 0.2). We conclude that a doxycycline-and-rifampin regimen is less effective than the doxycycline-and-streptomycin regimen in patients with acute brucellosis.

Impaired activity of natural killer cells in patients with acute brucellosis

Researchers have claimed that natural killer (NK) cells are involved in the mechanisms of defense of the host against infections. We have investigated the activity of NK cells in peripheral blood mononuclear cells (PBMNC) from 12 patients for whom acute brucellar infection has been diagnosed and from 14 healthy controls. The sera of eight of the patients were also analyzed 3 months after initiation of a 45-day course of antibiotic treatment, at which time they had no evidence of relapse. PBMNC from patients with acute brucellar infection showed a significantly depressed NK cell activity (P < .01) when compared with those from healthy controls; this depressed activity was not related to a deficient number of NK cells since the numbers of CD56+ and CD16+ cells present in PBMNC were similar in patients and controls. Incubation of PBMNC from patients with acute brucellar infection with recombinant interleukin-2, but not with interferon-gamma, can correct this impaired cytotoxic activity. In treated patients, there was a significant enhancement (P < .05) and normalization of the previously defective NK cell activity. It is concluded that acute brucellar infection is associated with a deficient cytotoxic activity of NK cells that can be overcome by in vitro incubation with interleukin-2 and that reverts to normal after antibiotic treatment.

[Brucellar sacroiliitis. A detailed review with an analysis of treatment efficacy]

All patients diagnosed of brucellosis in 4 regional hospitals during a period of nine years were reviewed, in an attempt to evaluate the efficacy of different antimicrobic regimens and also the clinical features. Evolution and complications of brucellar sacroiliitis. Of a total of 548 patients, 12% had been diagnosed of sacroiliitis and, of theme, 49 had complete data available with efficacy of different treatments, the time elapsed until fever and pain ceased was evaluated, together with initial therapeutic failures, relapses and length of hospital stay. Brucellar sacroiliitis is the most frequent osteoarthral complication of Brucella sp. in our setting. Keeping an stable incidence. It is predominant among young male (82%) population (mean age 25 +/- 12 years). The illness evolution is acute and less frequently subacute with a evolution mean-time before referral of 38 +/- 44 days (minimum 4 days, maximum 180 days). Fever (81%) and pain on gluteus and low lumbar localizations (100%) are the more frequent clinical features. Time elapsed until pain ceased was longer with doxycycline plus rifampicin (68 +/- 86) than with doxycycline plus streptomycin (28 +/- 43) (less than 0.05) and length of hospital stay was also longer with said treatment (p less than 0.05). There were no differences concerning time frame until fever ceased, initial therapy failures and relapses. Sequelae are infrequent and consist in persistency of pain. In resume response to treatment with usual regimens, doxycycline plus streptomycin of doxycycline rifampicin is good, being however time elapsed until pain ceases of mean length in hospital stay shorter in the group receiving doxycycline plus streptomycin. Control studies to confirm these data are need.