Predictive value of Toxoplasma gondii antibody titres on the occurrence of toxoplasmic encephalitis in HIV-infected patients. ANRS 005/ACTG 154 Trial Group

OBJECTIVE

To study the predictive value of anti-Toxoplasma gondii antibody titres for the occurrence of toxoplasmic encephalitis (TE) in HIV-infected patients.

METHODS

Data from the placebo arm of a trial of primary prophylaxis for TE (ANRS 005/ACTG 154) were analysed. Patients included had CD4+ cell counts < 200 x 10(6)/l and a positive Toxoplasma serology. Immunoglobulin (Ig) G and IgM Toxoplasma antibody titres at entry were retrospectively determined by enzyme-linked immunosorbent assay and agglutination on serum samples in a single laboratory. Incidence of TE was estimated by Kaplan-Meier method and a Cox model was used to study the predictive value of antibody titres, adjusted for other covariates.

RESULTS

All 164 patients studied were positive for IgG antibodies and one had IgM antibodies. After a mean follow-up of 16 months, 31 cases of TE were documented. One-year incidence of TE was significantly higher in patients with IgG titres > or = 150 IU/ml (23.7%) than in patients with titres < 150 IU/ml (7.7%; relative risk, 3.1; P < 0.003). IgG titres remained significantly associated with the occurrence of TE (relative risk, 3.3; P < 0.005) in the Cox model. Predictive value of IgG titres did not differ according to baseline CD4+ cell counts.

CONCLUSIONS

In patients with CD4+ cell counts < 200 x 10(6)/l, IgG anti-Toxoplasma antibody titre is a prognostic factor of occurrence of TE, with a higher risk for titres > or = 150 IU/ml. This finding should reinforce the recommendation of specific prophylaxis in these patients.

Toxoplasmose chez les patients immunodéprimés. Apport à la connaissance de l'infection toxoplasmique

Toxoplasmosis can be a severe infection in immunosuppressed patients. In these patients it can present as collected encephalitis, diffuse hypoxemic pneumopathy, or disseminated infection with fatal outcome. These presentations are observed mainly in HIV-infected patients, and less frequently in bone-marrow transplanted, or heart or heart and lung transplanted patients, or in patients given long term steroids or immunosuppressive therapy. The disease is due most often to the reactivation of latent persistent forms of the parasite at a moment of depression of host defense mechanisms, with local reactivation, and/or hematogenous dissemination. In some cases, the disease is favored by an insufficient protective response after primary infection. Treatment, based on the pyrimethamine-sulfadiazine combination should be continued as long as a profound immunosuppression is present. Prevention is based on recommendations to avoid acquisition of the parasite for seronegative patients, and on chemoprophylaxis, using cotrimoxazole as first line regimen, in patients already infected with Toxoplasma gondii.

Pyrimethamine for primary prophylaxis of toxoplasmic encephalitis in patients with human immunodeficiency virus infection: a double-blind, randomized trial. ANRS 005-ACTG 154 Group Members. Agence Nationale de Recherche sur le SIDA. AIDS Clinical Trial Group

Pyrimethamine (50 mg) with folinic acid (15 mg) given three times weekly was assessed as primary prophylaxis for toxoplasmic encephalitis (TE) in 554 human immunodeficiency virus-infected patients seropositive for Toxoplasma gondii and with < 200 CD4 cells/mm3. At 1 year, the incidence of TE was similar in pyrimethamine, 12%, and placebo, 13%, groups (relative risk [RR], 0.9; 95% confidence interval [CI], 0.6-1.4), and the survival rate was also similar, 85% and 80%, respectively (RR, 0.9; 95% CI, 0.7-1.2). Rash was the only adverse event that appeared significantly more frequently in the pyrimethamine arm (7% vs. 1%). In the on-treatment analysis, the incidence of TE was lower in the pyrimethamine arm, 4%, than in the placebo arm, 12% (P < .006). Thus, pyrimethamine cannot be recommended as a first-line regimen for primary prophylaxis of TE if the patient can take cotrimoxazole. However, it should be considered for patients who are intolerant to cotrimoxazole, especially in high-risk patients with < 100 CD4 cells/mm3.

High risk of HIV disease progression after infection through a sexual partner with AIDS

OBJECTIVE

To investigate whether HIV-1 infection acquired through a severely immunodepressed sexual partner increases the risk of disease progression.

DESIGN

A prospective cohort of patients infected through sexual contact at a known date and enrolled a few months (median, 2 months) after their first HIV-positive test. At enrolment, 12 subjects stated having had unprotected intercourse (anal or vaginal penetration) with a partner with AIDS within the 6 months prior to their first HIV-positive test. For the same period, 60 subjects stated having had unprotected intercourse with a partner, known to be HIV-positive, but who had not developed AIDS.

METHOD

The endpoint was the first occurrence of an HIV-related illness (group IV or AIDS, 1987 Centers for Disease Control and Prevention revised classification). Event-free survival curves since infection were constructed using the Kaplan-Meier method and compared by the log-rank test. The Cox model was used for multivariate analysis.

RESULTS

Disease progression was more rapid among the 12 subjects who stated having sex with a person with AIDS at a time close to infection, than among the other subjects (P = 0.03). Homosexuality and age at infection were also related to HIV disease progression. The adjusted relative risk of developing an HIV-related illness among those 12 subjects was 3.9 (95% confidence interval, 1.5-9.9).

CONCLUSION

Our results confirm the influence of virus-related factors on the onset of immunodepression in subjects infected through sexual contact.

Lower survival in AIDS patients receiving dapsone compared with aerosolized pentamidine for secondary prophylaxis of Pneumocystis carinii pneumonia. Study Group

A randomized, unblinded study compared aerosolized pentamidine, 300 mg every month, and dapsone, 50 mg/day, for secondary prophylaxis of pneumocystosis in 196 AIDS patients. The study was prematurely discontinued due to excess mortality in the dapsone group. After a mean follow-up of 13 +/- 6.4 months, 22 (21%) of 103 patients in the pentamidine group were dead compared with 39 (42%) of 93 receiving dapsone; the estimated mortality rates at 18 months were 24.6% and 53.1%, respectively (P < .003, log-rank test). A negative interaction was observed between zidovudine and dapsone (P < .049, interaction test of Cox model), and the mean CD4 cell count during the study was lower in the dapsone (49 +/- 61/mm3) than in the pentamidine group (83 +/- 88/mm3; P < .002, t test). The lower survival might also be related to the oxidative effect of dapsone or to the addition of iron protoxalate to dapsone in this study. These results suggest caution in using dapsone as long-term therapy in advanced human immunodeficiency virus infection, especially in those receiving zidovudine.

[Pneumopathies caused by Streptococcus pneumoniae in 27 HIV infected patients]

OBJECTIVES

Determine the clinical features and outcome of acute pneumonia due to Streptococcus pneumoniae in HIV infected patients compared with non-HIV infected patients.

METHODS

From January 1986 to February 1992, we observed 33 episodes of pneumococcal pneumonia in 27 HIV-infected patients. Most of the patients were drug addicts (16/27), and/or originated from Central Africa or Haiti (10/27). In 9/27 (33%) patients, HIV infection was previously unknown. Eleven of the 27 patients were at the CDC stages II-III and CD4 cell count was greater than 200/mm3 and CD8 cell count was greater than 1000/mm3 in 12/23 patients and 10/20 patients respectively.

RESULTS

In 10/33 episodes, respiratory symptoms were severe: bilateral pneumonia (n = 2) and/or hypoxaemia (n = 9). In 22/33 episodes, hospitalization occurred less than 24 h after the onset of symptoms and in 9/33 episodes, the initial chest X-ray was normal. Streptococcus pneumoniae was isolated in 16/33 episodes, from blood (n = 10), bronchoalveolar lavage (n = 3) or sputum (n = 3). Penicillin G or amoxicillin was used and allowed a favorable and quick response in all episodes. Recurrence occurred in 5/18 (27%) followed patients. These recurrences were not favoured by a low CD4 cell count since it was more than 200/mm3 in these five patients. However, the mean count of CD8 cells was higher in patients with recurrence than in patients without recurrence, 1990/mm3 versus 995/mm3 (p = 0.03).

CONCLUSION

CD8 hyperlymphocytosis could increase the risk of recurrence and would help identify a subgroup with higher risk of pneumococcal pneumonia among HIV infected persons.

Activities of roxithromycin against Mycobacterium avium infections in human macrophages and C57BL/6 mice

The activity of roxithromycin against three clinical isolates of Mycobacterium avium was compared with that of clarithromycin both in a model of infection of human monocyte-derived macrophages and in a model of established infection of C57BL/6 mice. In the cell culture model, roxithromycin and clarithromycin were bactericidal for strains MO-1 and N-92159 and bacteriostatic for strain N-93043. For the three strains, the differences between the intracellular activities of roxithromycin and clarithromycin were not singificant after 7 days of treatment. Mice were infected with the MO-1 strain. Drugs were given by gavage at a dosage of 200 mg/kg of body weight 6 days per week for 16 weeks starting 5 weeks after infection. At the end of treatment, clarithromycin was more effective than roxithromycin in lungs; roxithromycin was as effective as clarithromycin in spleens. Thus, the activity of roxithromycin was comparable to that of clarithromycin both in vitro and in vivo.

Pyogenic and tuberculous spondylodiskitis (vertebral osteomyelitis) in 80 adult patients

Bacterial spondylodiskitis--i.e., adjacent vertebral osteomyelitis and diskitis--was studied in 80 adult patients. The infection was due to Mycobacterium tuberculosis in 31 cases (39%) and to pyogenic bacteria in 49 cases (61%). The latter pathogens included gram-negative bacilli in 16 cases (20%), Staphylococcus species in 15 (19%), Streptococcus species in 9 (11%), and Corynebacterium species in 1 (1%); the pathogens in the 8 remaining cases (10%) were not identified. Of the patients with tuberculous spondylodiskitis, 55% came from countries where tuberculosis is endemic (P < .001). Cases due to staphylococci and those due to M. tuberculosis were associated with a high frequency of previous active infection with those respective organisms at any site (47% and 42%, respectively; P < .001) and with a high rate of neurological complications (33% and 32%, respectively; P < .001). Nine patients with pyogenic spondylodiskitis (18%) but only one patient with tuberculous spondylodiskitis (3%) had diabetes mellitus (P < .05). Blood cultures were positive in 23 (56%) of the 41 cases of pyogenic spondylodiskitis due to an identified bacterium. Discovertebral needle biopsy contributed to the bacteriologic diagnosis in 29 (74%) of 39 cases.

Empiric antituberculosis treatment: benefits for earlier diagnosis and treatment of tuberculosis

SETTING

Tuberculosis may be diagnosed too late, especially in HIV-infected patients, with consequences on bacillus transmission and survival. Empiric antibuberculosis treatment (EATT) may be started before diagnosis of tuberculosis is confirmed. As rifampicin is a broad spectrum antibiotic, EATT including rifampicin may be effective in infections other than tuberculosis, leading to misdiagnosis.

OBJECTIVE

To define the efficiency criteria of EATT with or without rifampicin.

DESIGN

Between 1988 and 1991, 20 febrile patients with suspected tuberculosis (including 15 who were HIV-positive) were started on EATT in the absence of bacteriological or histological proof of tuberculosis. 10 patients (50%) received a 4-drug non-specific EATT including rifampicin, isoniazid, pyrazinamide and ethambutol, and 10 (50%), received a 3-drug specific EATT without rifampicin.

RESULTS

In 10 patients (50%), the diagnosis of tuberculosis was confirmed by positive cultures within a mean of 32 days (15-57 days) after the beginning of EATT (group TB 1). Of the 10 patients whose cultures remained negative, 4 (20%) became afebrile and showed improvement under EATT (group TB 2), and 6 (30%) remained febrile and did not improve (group No TB). Patients from groups TB 1 and TB 2 became afebrile within a mean of 11 days (1-54 days). This delay was not different between patients receiving specific or non-specific EATT. In patients receiving specific EATT, rifampicin was added to the initial 3-drug treatment after resolution of fever.

CONCLUSION

EATT appears to be a useful method for rapid presumptive diagnosis and treatment of tuberculosis.

[Multicenter French cohort of adults with HIV infection. Description and course after 4 years of follow-up. SEROCO]

OBJECTIVES

A prospective multicentric epidemiological study (SEROCO) of subjects with a diagnosis of human immunodeficiency virus (HIV) infection was started on January 1, 1988 in order to better understand the natural history of HIV infection and factors related to outcome. Observations after 4 years of follow-up are reported here.

METHODS

After authorization by the French national ethics committee and the national commission for personal freedom, 18 French centres included non-haemophiliac volunteers who were asymptomatic, had had non anti-HIV treatment and whose HIV positivity had been known less than 1 year at inclusion. These last three criteria were not required for patients whose precise date of contamination was known within a range of +/- 3 months.

RESULTS

On July 15, 1992, there were 1453 infected subjects in the cohort (1063 males, 417 females; age range at inclusion 18-75 years; mean age 31.3 +/- 9.4). Globally, 2.7% of the subjects were symptomatic at inclusion. Mean CD4 lymphocyte count at inclusion was 508/mm3. Clinically, 51.5% of the patients had a history of sexually transmitted disease at inclusion. After 4 years (on July 15, 1992) mean follow-up was 28 +/- 12.9 months for a total of 3428 patient-years. Disease progression to stage IV was observed in 439 patients including 202 who developed the acquired immuno-deficiency syndrome (AIDS). Among these 202 patients, 113 had died at the end-point of this report. The first manifestation of AIDS was Kaposi sarcoma in 44, pulmonary pneumocystosis in 38 and cerebral toxoplasmosis in 27. The probability of developing AIDS was calculated at 13.9% at 5 years, 27.7% at 7 years and 33.7% at 10 years. The probability of a CD4 count below 200/mm3 was 32.7, 55.6 and 67% at 5, 7 and 10 years respectively. For patients with a CD4 count below 200, the probability of developing AIDS was 18% at 1 year, 39% at 2 years and 51% at 3 years.

CONCLUSIONS

SEROCO has been a most useful prospective epidemiological tool due to the diversity of the subjects included. The observed natural history of HIV infection will lead to specific research projects aimed at better understanding the disease process.

Chloroquine does not enhance the activity of clarithromycin against multiplication of Mycobacterium avium within human macrophages

SETTING

Chloroquine, an alkalinizing lysosomotropic agent, enhances the intracellular activity of antibiotics against Mycobacterium tuberculosis or Coxiella burnetii.

OBJECTIVE

To determine if chloroquine modifies the activity of clarithromycin, less effective at acidic pH, against intracellular Mycobacterium avium.

DESIGN

The activity of clarithromycin (4 micrograms/ml) against the MO-1 strain of M. avium was evaluated within human macrophages in presence of chloroquine (5 micrograms/ml). The minimal inhibitory concentration of clarithromycin for the strain was 2 micrograms/ml.

RESULTS

While clarithromycin alone did decrease the intracellular infection at day 7 of culture (P < 0.01), chloroquine alone did not impede the intracellular growth of M. avium, and did not enhance the activity of clarithromycin.

CONCLUSION

Chloroquine should not improve clarithromycin treatment against M. avium infection.

Cytomegalovirus colitis in HIV-1-infected patients: a prospective research in 55 patients

OBJECTIVE

To determine criteria for the diagnosis of cytomegalovirus (CMV) colitis and to analyse stages of the course and prognosis of CMV colonic involvement in HIV-1-infected patients.

DESIGN

Prospective search for CMV colonic involvement with systematic biopsies to search for CMV intranuclear inclusion bodies and for CMV culture. The evolution of CMV colonic involvement was estimated using further coloscopies and autopsy.

SETTING

Infectious diseases department in a tertiary referral teaching hospital in Paris, France.

PARTICIPANTS

Fifty-five consecutive patients with HIV-1 infection, who had not previously received anti-CMV drugs, and who had at least one coloscopy performed.

RESULTS

According to initial coloscopy, colitis, either ulcerative or inflammatory, was found in nine (16%) out of the 55 patients, CMV intranuclear inclusions were present in the colon of four (7%) patients, and colonic cultures were positive for CMV in 15 (27%) patients. The results of the initial coloscopy showed a positive correlation between endoscopic colitis (either ulcerative or inflammatory), CMV inclusions and positive CMV culture from colonic biopsies. The absence of endoscopic ulcerative lesions had a 98% (49 out of 50) negative predictive value for recording CMV inclusions in the colon (95% confidence interval, 89-100). CMV inclusions were recorded in three out of five ulcerative colitis. Male homosexuality, HIV-1 infection stages IVB, C1, D or E, according to the Centers for Disease Control and Prevention classification, CD4 lymphocyte count < 200 x 10(6)/l and CMV viraemia also correlated positively with CMV colonic involvement. During the observation period (mean, 7.3 months), the estimated incidence of CMV colitis according to coloscopic studies was 13%. Deterioration in condition was the most frequent spontaneous evolution of CMV colonic infection, whereas anti-CMV treatment resulted in an improvement. Ulcerative lesions occurred earlier in patients with colonic CMV inclusions or positive colonic CMV culture than in patients without CMV colonic involvement at the initial coloscopy. CMV colitis occurred late in the course of HIV-1 infection, on average 4 months before death. The presence of CMV inclusions was an indicator of poor prognosis with earlier occurrence of CMV viraemia and retinitis and no survival after 9 months.

CONCLUSIONS

These results confirm that the colon is a target organ for CMV in HIV-1-infected patients. Coloscopy should be used to diagnose CMV colitis, because of the close correlation between endoscopic and histological data (i.e., intranuclear inclusions). This combination allows us to propose an evolutive staging of CMV colonic involvement and provide stratification criteria to assess the efficacy of anti-CMV drugs.

Prolonged and fatal disseminated cytomegalovirus infection in an immunocompetent woman

The case of an immunocompetent woman who died of disseminated cytomegalovirus infection with encephalitis and skin ulcerations is reported. The duration of the disease, from onset to death, was five months. Cytomegalovirus was found in the blood, urine, skin, muscle, liver and periventricular brain tissue, but not in frontal cortex tissue. This case underlines the fact that cytomegalovirus may exceptionally cause life-threatening illness in immunocompetent adults.

[Vancomycin in meningitis caused by penicillin G resistant Streptococcus pneumoniae]

We report two cases of penicillin G-resistant pneumococcal meningitis in adults, with clinical and bacteriological failure of amoxicillin and negative or incomplete response to third generation cephalosporins. Meningitis occurred in a man treated for myeloma and in an elderly woman under prolonged intermittent amoxicillin therapy for chronic otitis. Such situations are known as exposing to pneumococcal meningitis and to resistance of the strain involved to penicillin G. Both patients were cured by vancomycin in continuous infusion associated with rifampicin or fosfomycin. Contrary to third generation cephalosporins, which have higher minimal inhibitory concentrations, vancomycin and rifampicin are still fully active against penicillin G-resistant pneumococcal strains. Thus, vancomycin administered in continuous infusion and associated with rifampicin and fosfomycin deserves to be tried as first-line treatment of pneumococcal meningitis in patients at risk of resistance to penicillin G.

Pyrimethamine plus azithromycin for treatment of acute toxoplasmic encephalitis in patients with AIDS

A prospective study was conducted to evaluate azithromycin in combination with pyrimethamine for treatment of acute Toxoplasma encephalitis in patients with AIDS. Of the 14 patients given 75 mg pyrimethamine and 500 mg azithromycin daily for four weeks, eight were evaluable for clinical response. Five responded favorably, one had an intermediate response and two an unfavorable response. Of the nine patients evaluable for radiological response, six responded favorably, and three had an intermediate response. Eleven adverse events occurred in nine patients: rash (n = 5), abnormal liver function (n = 2), vomiting (n = 3) and hypoacousia (n = 1). This pilot study suggests that the combination of pyrimethamine and azithromycin may be further investigated and that the optimal dosage of azithromycin has yet to be determined.