HIV-2 and HIV-1 AIDS cases in Senegal: clinical patterns and immunological perturbations.

The serological and immunological parameters, disease patterns, and social characteristics of 39 human immunodeficiency virus type 2 (HIV-2) seropositive CDCIV cases seen in Dakar, Senegal were studied. These data were compared with those obtained from 48 HIV-1 seropositive CDC stage IV patients. Social characteristics of populations infected with HIV-1 or HIV-2 were clearly different. A patient sex ratio of three men to one woman was found for both viruses. In addition, the immune status of nonsymptomatic HIV-1 and HIV-2 seropositive people was evaluated. The correlation between abnormalities of the immune system and clinical status was similar for the two infections. Clinical symptoms of both diseases were the same, but this cross-sectional study could not address the questions of differences between the two infections in latency and development of disease or specific manifestations of HIV-2 infection. This study suggests that HIV-2 infection may contribute to the present AIDS epidemic in West Africa.

Flow cytometry detection of surface antigens on fresh, unfixed red blood cells infected by Plasmodium falciparum.

The immunofluorescence detection of parasite-specific antigens on the surface of red blood cells infected by Plasmodium falciparum parasites is usually performed by visual detection under a fluorescence microscope. We describe here a technique permitting the analysis of surface immunofluorescence labelling by flow cytometry. Infected red blood cells are selected on the basis of their parasitic DNA and RNA content by Hoechst and Thiazole Orange vital dyes. Cytometric analysis of these labels, as well as general erythrocyte characteristics assessed by analysis of forward and side scatter allows the selection of viable intact infected erythrocytes from other blood cells. The integrity of these selected erythrocytes was confirmed by the absence of labelling with antibodies directed against internal components such as spectrin. This technique permits the detection of specific surface immunofluorescence staining on red blood cells infected with mature stages of P. falciparum by antibodies in sera from hyperimmune Saimiri monkeys. Using Thiazole Orange dye for detection of parasitised cells, this analysis was performed on a FACSscan apparatus equipped with a single laser.

Acute Plasmodium falciparum infection is associated with increased percentages of apoptotic cells.

The impact of acute malaria infection on the level of spontaneous apoptosis, i.e., the percentage of apoptotic cells detectable in lymphocytes cultured without any exogenous stimulus for 3 days in vitro, was evaluated. Quantitation of apoptosis was performed by staining of lymphocyte nuclei with propidium iodide and analysis of the fluorescence by cytometry. The mean apoptosis of 23 HIV-negative patients (15 Africans and 8 Europeans) determined during a confirmed Plasmodium falciparum attack was 27.2% (95% confidence interval (CI) = 23.5-30.7%) i.e., 2.2 times the mean level found in 49 controls (12.4%, CI = 11.1-13.6). These controls included age- and sex-matched Africans (n = 37) and Europeans (n = 12) differing only by their previous level of exposure to P. falciparum. Naive (European) as well as previously exposed (African) subjects showed dramatically elevated levels of spontaneous apoptosis during the malaria attack (mean = 22.5%, CI = 20.7-24.4 for Europeans; mean = 29.7%, CI = 24.6-34.7 for Africans). Such unusually raised levels were observed for at least 1.5 months and were probably detectable for longer periods as suggested by the fact that the mean level of spontaneous apoptosis in healthy Africans was basically higher (13.8%, CI = 12.5-15) than the one found in healthy Europeans (8.2%, CI = 6.3-10.1) (P = 0.0001). Selective immunomagnetic cell isolations carried out immediately before apoptosis quantitation showed that this process affected not only the alpha beta T cells (CD4+ T cells as well as CD8+ T cells) but also the gamma delta T cells and the B-lymphocyte subset.(ABSTRACT TRUNCATED AT 250 WORDS)

Severe malaria in African adults living in a seasonal endemic area.

OBJECTIVE: This study investigates severe malaria in African adults living in a seasonal endemic area. DESIGN: A prospective study of all adults admitted with severe malaria over 2 consecutive seasons: October 1990 till January 1991 and October 1991 till January 1992. SETTING: ICU (15 beds) of Hôpital Principal, Dakar, Sénégal. PATIENTS: 23 patients: 14 men and 9 women with a mean age of 30 +/- 3 years were included in the study; all fulfilled the 1990 WHO criteria for severe malaria. RESULTS: At admission, 12 patients were comatose (Glasgow Coma Scale < 10), 7 had generalized convulsions. Parasitaemia was 135 +/- 52 x 10(9)/l. Biological indications of severity were as follows: hypophosphataemia < 0.8 mmol/l in 14 cases, serum creatine phosphokinase > 500 IU/l in 15 cases; and PaO2 < 70 mmHg in 5 cases. Serum TNF alpha levels, measured in 16 cases, were increased at 298.4 +/- 63.5 pg/ml, serum levels of IL-6 and IL-2SR were also elevated: 609.5 +/- 304.2 pg/ml and 297.6 +/- 35.6 pg/ml respectively. Circulating IgM and IgG antibodies were found in 14 out of 16 patients. Serum levels of TNF alpha, IL-6 and IL-2SR correlated positively with each other. TNF alpha and IL-2SR were also positively correlated to parasitaemia. Intravenous therapy with quinine at loading dose was favorable in 19 patients. Four patients died during the study, 3 from multiple organ failure. CONCLUSIONS: This work demonstrated that severe malaria in a seasonal endemic area displays original clinical features with a high rate of either cerebral malaria or multiple organ failure.

Human immune responses to the highly repetitive Plasmodium falciparum antigen Pf332.

The B and T cell responses to EB200, a repetitive part of the Plasmodium falciparum antigen Pf332, were examined in malaria-exposed Senegalese adults. Most donors had high levels of antibodies to recombinant EB200 and 17 overlapping peptides spanning EB200. Taking proliferation and/or cytokine (interferon-gamma and interleukin-4) production as a measure of T cell activation, eight of the EB200-derived peptides induced responses in > 40% of the donors tested. There was no general association between the different types of T cell responses measured, emphasizing the importance of including multiple parameters when analyzing T cell responses and suggesting that EB200 induces functionally distinct T cell responses. The most efficient peptide for induction of proliferative responses was one previously shown to induce T cell responses in five different H-2 congenic mouse strains primed with EB200, suggesting that this is a universal T cell epitope. The presence of multiple B and T cell epitopes in EB200, widely recognized by humans, is important since EB200 has been shown to elicit protective antibody responses in monkeys and may be considered for inclusion in malaria subunit vaccines.

Pattern of immunoglobulin isotype response to Plasmodium falciparum blood-stage antigens in individuals living in a holoendemic area of Senegal (Dielmo, west Africa).

Three cross-sectional studies were conducted in a representative cohort of individuals living continuously in an area holoendemic for malaria in Senegal. Plasma from 145 children and adults were tested. The pattern of antimalarial immunoglobulin class (IgM and IgG) and subclass (IgG1 to IgG4) antibody distribution was determined by enzyme-linked immunosorbent assay using a crude blood-stage antigen of Plasmodium falciparum-infected red blood cells. Adults had higher levels of specific antibodies than children, and IgM, IgG2, and IgG3 accounted for the highest difference (2.9, 6.5, and 4.5 times, respectively). Differences in antibody levels were significant for IgG1 to IgG4 between the lowest and the highest transmission season. No particular isotype distribution pattern could be found associated with any given parasitemia level. The relationship between the optical density (OD) values of each isotype and the risk of clinical malaria attack was tested using a Poisson regression model. Only the IgG3 OD increases were found associated with a significantly reduced risk of malaria attack. These seroepidemiologic data suggest that whereas the total IgG-specific activity is not indicative of any given level of protection against malaria, the level of IgG3 was significantly associated with the relative susceptibility to clinical P. falciparum malaria attacks.

Plasmodium falciparum parasites in French Guiana: limited genetic diversity and high selfing rate.

The genetic characteristics of Plasmodium falciparum isolates collected in French Guiana, where malaria transmission is low and occurs in isolated foci, were studied. Blood samples were collected from 142 patients with symptomatic malaria and typed using a polymerase chain reaction-based strategy for merozoite surface protein-(MSP-1) block 2, the MSP-2 central domain, and glutamate-rich protein (GLURP) repeat domain polymorphism. This showed that the parasite population circulating in French Guiana presented a limited number of allelic forms (4, 2, and 3 for MSP-1 block 2, MSP-1, and GLURP, respectively) and a small number of mixed infections, contrasting with the large genetic diversity of parasite populations and infection complexity reported for Africa, Asia, and other parts of South America. Two groups of isolates displaying identical 3 loci allele combinations were further studied for the Pf332 antigen, histidine-rich protein-1, thrombospondin-related anonymous protein, and Pf60 multigene family polymorphism. Within each group, most isolates were identical for all markers tested. This suggests a high rate of self-fertilization of P. falciparum parasites in French Guiana, resulting in homogenization of the population. The implications of these findings for malaria control in areas of low endemicity are discussed.

Tonate virus infection in French Guiana: clinical aspects and seroepidemiologic study.

Two recent cases of human infection with Tonate virus, one of which was a fatal case of encephalitis, have renewed interest in these viruses in French Guiana. The clinical aspects of confirmed and probable cases of infection with this virus indicate that it has pathogenic properties in humans similar to those of other viruses of the Venezuelan equine encephalitis complex. To determine the prevalence of antibodies to Tonate virus in the various ethnic groups and areas of French Guiana, 3,516 human sera were tested with a hemagglutination inhibition test. Of these, 11.9% were positive for the virus, but significant differences in seroprevalence were found by age, with an increase with age. After adjustment for age, significant differences were found between places of residence. The prevalence of antibody to Tonate virus was higher in savannah areas, especially in the Bas Maroni (odds ratio [OR] = 22.2, 95% confidence interval [CI] = 15.2-32.4) and Bas Oyapock areas (OR = 13.4; 95% CI = 9.8-18.4). The ethnic differences observed in this study were due mainly to differences in place of residence, except that whites were significantly less frequently infected than other ethnic groups. This study indicates that Tonate virus infection is highly prevalent in French Guiana, especially in savannah areas.

Mayaro virus fever in French Guiana: isolation, identification, and seroprevalence.

This paper reports the first isolation of Mayaro (MAY) virus from a patient infected in French Guiana. The identification was initially performed using immunofluorescent antibody testing with specific mouse antibody, and confirmed by plaque-reduction neutralization testing and reverse transcription-polymerase chain reaction. To determine if MAY virus infection is widespread in French Guiana, a serosurvey was performed to determine the prevalence of antibody to this virus in various ethnic groups and areas of French Guiana. Human sera (n = 1,962) were screened using the hemagglutination inhibition (HI) test. To determine whether MAY virus circulates in the rain forest, a serosurvey in monkey populations was performed. Monkey sera (n = 150) were also screened for antibody to MAY virus using HI testing. Of the human sera tested, 6.3% were positive for anti-MAY virus antibodies. Significant differences in MAY virus seroprevalence between different age groups were observed. Seroprevalence rates increased with age, with a large increase in people 10-19 years of age in comparison with those less than 10 years of age. After adjustment for age, significant differences were also found between places of residence. The prevalence of anti-MAY virus antibody was higher in people living in contact with the forest, especially in the Haut Oyapock area (odds ratio [OR] = 97.7, 95% confidence interval [CI] = 48.2-197.9) and along the Maroni River (OR = 39.7, 95% CI = 20.6-76.6). The ethnic differences observed in this study were probably due to differences in residence. Among monkeys, higher seroprevalence rates were found in Alouatta seniculus (66.0%) than in Saguinus midas (18.2%). Among Alouatta, the seroprevalence increased significantly with weight (and therefore with age). This study indicates that MAY virus is present in French Guiana, and human infections occur in areas where people live near the tropical rain forest.

Extensive genetic diversity of Plasmodium falciparum isolates collected from patients with severe malaria in Dakar, Senegal.

While some genetic host factors are known to protect against severe Plasmodium falciparum malaria, little is known about parasite virulence factors. We have compared the genetic characteristics of P. falciparum isolates collected from 56 severe malaria patients and from 30 mild malaria patients recruited in Hôpital Principal, Dakar, Senegal. All isolates were typed using polymerase chain reaction amplification of polymorphic genetic loci (MSP-1, MSP-2, HRP1, GLURP, CSP, RESA, and the multigene family Pf60). The complexity of infections was lower in severe than in mild malaria and the parasite genetic diversity in both groups was very large. No specific genetic make-up was associated with severity; there were, however, marked differences in allele frequencies in both groups, with a prevalence up to 60% of MSP-2 alleles specifically observed in the severe malaria isolates. In addition, the presence of MSP-1/RO33 alleles was significantly associated with a higher plasma level of tumour necrosis factor alpha receptor 1 (P < 0.05), a reported indicator of severity in human malaria. These results point to potential differences in the genetic characteristics of parasites inducing severe versus mild pathology.

A study of the genomic diversity of Plasmodium falciparum in Senegal. 1. Typing by Southern blot analysis.

The genomic polymorphism of Plasmodium falciparum was investigated in a series of samples collected in Senegal during one transmission season. Restriction site polymorphism was studied by Southern blot analysis using six different probes. The patterns of the ribosomal RNA genes and of the gene coding for antigen 2L indicated a limited genomic polymorphism. Sequences hybridizing to the repeats of the Palo Alto/Wellcome serotype of S-antigen were found in one out of twelve isolates examined. This strain was shown to express the Palo Alto serotype. Restriction fragment length polymorphism was observed for the 332 gene and the 11.1 locus. The hybridization patterns showed that each sample had a distinct 11.1 locus. A comparison of three probes (332, 11.1 and rep20) detecting fragment length polymorphism indicated that maximum sensitivity was obtained using the subtelomeric repeats rep20; less sensitive patterns were observed using the 11.1 27 bp repeat probe. By using these three probes it was found that all samples were genetically distinct.

A study of the genomic diversity of Plasmodium falciparum in Senegal. 2. Typing by the use of the polymerase chain reaction.

The genomic polymorphism of Plasmodium falciparum was investigated in a series of samples collected in Senegal during one transmission season. PCR analysis was performed on several genes coding for blood-stage antigens: the gene for the major merozoite surface antigen P190, the gene for the second merozoite surface antigen MSA2 and the gene coding for antigen 96tR/GBP130. In each case, several distinct forms of the genes studied were observed. Both the MAD20 and K1 allelic families of P190 genes were observed. PCR analysis of a single variable region did not differentiate each isolate. However, when the data obtained for several markers are combined, each isolate had a specific genotype. Thus, using PCR to study in parallel several loci is a useful tool to genetically type strains.

Lymphocyte response in vitro to Plasmodium falciparum merozoite antigens in donors from a holoendemic area.

Crude merozoite antigens from P. falciparum were used to analyse the proliferative response of peripheral blood mononuclear cells from 114 inhabitants of the village of Dielmo (Senegal, West Africa), who are exposed continuously to malaria transmission. The high or low responses to merozoite antigens obtained in lymphocyte stimulation assays were correlated to the presence or absence of parasites, to the IFN-gamma production and to the HLA-phenotype. High responders produced high levels of IFN-gamma while low responders did not secrete IFN-gamma (23/27). The two HLA phenotypes HLA-B51 and HLA-DR1 were significantly associated with high response (p < 0.05).

[Yellow fever virus, dengue 2 and other arboviruses isolated from mosquitos, in Burkina Faso, from 1983 to 1986. Entomological and epidemiological considerations]. / Virus amaril, dengue 2 et autres arbovirus isolés de moustiques, au Burkina Faso, de 1983 a 1986. Considérations entomologiques et épidémiologiques.

An arbovirus surveillance was carried out in Burkina Faso from 1983 to 1986. It was based on crepuscular catches of mosquitoes on human bait in some wooded areas and in one town. The total collection was 228 catches with an average of 8 men per catch. The total number of mosquitoes caught was 44,956 among which 32,010 potential vector of yellow fever; all these mosquitoes were analysed for arbovirology. In the south-western part of the country (region of Bobo-Dioulasso), surveillance was conducted each year from August to November, whilst the circulation of Aedes-borne arboviruses is well known to be favoured. In 1983, 1984 and 1986, seven strains of yellow fever virus were isolated in circumstances remarkably similar. They came from selvatic areas and never from the town. They concerned only Aedes (Stegomyia) luteocephalus which is the very predominant potential vector of yellow fever in the region. They were obtained in low figure, between 1 and 4 per year. They occurred from 27th of October to 21th of November. These observations confirm that the southern portion of the Sudan savanna zone of West Africa is the setting of a customary circulation of yellow fever virus and therefore belongs to the endemic emergence zone. In 1986, two strains of dengue 2 virus were isolated. One concerned Ae. luteocephalus from the selvatic area, the other Ae. (St.) aegypti from the heart of town. These data suggest two distinct cycles for dengue 2 virus, one urban and one selvatic, which could coexist simultaneously in the same region. In the south-eastern part of the country (region of Fada-N'Gourma) a yellow fever epidemic occurred between September and December 1983; its study has enable to precise their entomological aspects. The entomological inoculation rate of yellow fever virus has been evaluated to 22 infected bites per man during the month of october, for a man living close to forest gallery. 25 strains of yellow fever virus strains was isolated from Ae. (Diceromyia) furcifer which is the potential vector the most abundant in this region: the main role of this species in an epidemic was confirmed. An investigation in September 1984 had not permitted isolation of the virus therefore it is suspected that the large epizootic circulation of virus in 1983 has not been renewed the year after. In total 59 viral strains belonging to 10 different viruses were isolated from 9 species of mosquitoes.(ABSTRACT TRUNCATED AT 400 WORDS)

[Severe malaria in an African seasonal endemic area. Comparison of aspects in adults and children and prognostic value of cytokines]. / Paludisme grave en zone d'endémie saisonnière Africaine. Comparaison des formes de l'adulte et de l'enfant et valeur pronostique des cytokines.

OBJECTIVES: The present study was conducted in West Africa in a region where malaria exists as a seasonal endemic disease. The aim was to compare clinical and biological aspects of adult severe falciparum malaria with those found in children and to appreciate the role of cytokines a prognostic markers. Thirty-one patients fulfilling the WHO criteria of severe malaria were included. METHODS: Fifteen children (8 boys and 7 girls; mean age: 7.9 +/- 3.7 years) were compared with an adult group of 16 patients (9 men and 7 women; mean age: 31.1 +/- 14.5 years). The number of severe criteria and most of the biological features (glycaemia, parasitaemia, haemoglobin levels, platelet count) were similar in both groups. As regards immunological findings, serum levels of IgM and IgG were significantly increased in the adult group. Serum levels of TNF alpha, IL-6 and IL-2SR were similar (255.2 +/- 375.3 versus 298.4 +/- 254.1 pg/ml for TNF alpha, 534.6 +/- 642.7 versus 609.5 +/- 1217.0 pg/ml for IL-6, 253.1 +/- 120.5 versus 297.6 +/- 142.2 pg/ml for IL-2SR). Each of these cytokines correlated with the others and were also correlated to parasitaemia. Three children and two adults died during the course of the study. At admission a significant died during the course of the study. At admission a significant difference was observed between serum levels of TNF alpha (p < 0.01), IL-6 (p < 0.001) and IL-2SR (p < 0.05) in patients who were later survivors or non-survivors. CONCLUSION: This study confirms the prognostic significance of serum levels of TNF alpha, IL-6 and IL-2SR in severe malaria.

[Human immunodeficiency virus infections (HIV-1 and HIV-2) in Dakar. Epidemiologic and clinical aspects]. / Infections par les virus de l'immunodéficience humaine (VIH1 et VIH2) à Dakar. Aspects épidémiologiques et cliniques.

The authors report on the results of an investigation carried out on 109 HIV seropositives ascertained by the Dakar Central Hospital between February 20, 1987 and May 31, 1988. These seropositives affected 44 patients with AIDS (0.78% of admitted patients) and 65 seropositive people of which 43 blood donors (1.35% of donors). Both viruses are present in about equal number: 50 HIV1 seropositives, 44 HIV2 seropositives, and 15 composite seropositives. Sex-ratio is 3,9 in favour of males; this figure is nearer to the one observed in Europe and North American than the one observed in Central Africa where there is equality between both sex. Clinical patterns are dominated by a bad general status: lost of weight, fever, diarrhea, polyadenopathiae, pneumopathiae, meningoencephalitis. Kaposi's sarcoma and cryptococcal meningitis have been observed only four times. Development of the infection lead to death for 12 patients during the 16 months of the investigation. Both viruses are responsible for an equal immunodepression, leading to the same potential severity. Immunodepression might be acquired more slowly with HIV2, so strongly suggesting an incubation apparently lasting more.

PIP: Between February 1987-May 1988, 109 patients at the Dakar Central Hospital were diagnosed by the ELISA method and confirmed by Western Blot as seropositive for HIV infections. 44 had AIDS, including 2 blood donors and 1 child. 39 asymptomatic but seropositive subjects included 15 blood donors, 7 spouses and 2 children of seropositive individuals, 2 subjects who had spent time in Central Africa where HIV is endemic, 2 patients receiving blood transfusions in Benin and the Ivory Coast, 2 patients with a positive treponemic serology, 4 pregnant women, and 5 patients with disorders unrelated to AIDS. The remaining 26 seropositive blood donors were not examined and their risk factors and health status were unknown. Among the 109 cases there were 50 seropositivities to HIV 1, 44 to HIV 2, and 15 for both HIV 1 and 2. 83 men and 26 women were seropositive, for a sex ratio of 3.9. The average ages of AIDS patients were 33.2 for HIV 1, 41.1 for HIV 2, and 42.3 for HIV 1 and 2. Average ages of asymptomatic carriers were 30.1 for HIV 1, 29.5 for HIV 2, and 26.1 for HIV 1 and 2. Risk factors were difficult to study, but 78 records including information indicated 3 open homosexuals, 4 drug users, 25 who frequented prostitutes, 11 patients who had received transfusions, and 30 who had received injections. 21 of 35 seropositive for HIV 1, 5 of 33 seropositive for HIV 2, and 5 of 10 seropositive for both HIV 1 and 2 had lived outside Senegal and its neighboring countries in the past 10 years. Clinical signs in the 44 AIDS patients were highly varied. The most frequently noted were poor general state with weight loss, fever, diarrhea, polyadenopathic syndrome, pneumopathy, and meningoencephalitis. 9 men and 3 women died during the study period. In all cases the clinical status at hospital admission was very poor. There has as yet been no epidemic of AIDS in Senegal following observation of the 1st case in 1987. The 44 AIDS patients represented .78% of hospital admissions during the study period, while the 43 seropositive blood donors represented 1.35% of all donors. The HIV 1 and HIV 2 viruses both cause profound immunodepression. Some evidence suggests that the HIV 2 virus has a longer incubation period. The study indicates that the epidemiology of HIV is not the same in West Africa as in Central Africa.

[Epidemic of yellow fever in the southeastern region of Upper Volta (October-December, 1983). Epidemiological study. Preliminary results]. / L'épidémie de fièvre jaune du sud-est de la Haute-Volta (octobre-décembre 1983). Etude épidémiologique. Résultats préliminaires.

An epidemic of yellow fever raged during the last three months of 1983 in South East of Upper Volta. It spread on about ten thousand square kilometers, in a bushy savanna area, affecting only populations living in contact with forest galleries, belonging especially to the peul ethnical group. The transmission of the virus was effected by sylvatic vectors, essentially Aedes furcifer. Serological tests showed that about 50 % of the population living in contact with forest galleries was affected, that is to say 15.000 to 17.500 people. The average death rate on the whole area was 4 % (800 to 1.700 deaths); the lethality rate was estimated between 6 and 10 % of affected people. On the whole, 54 strains of yellow fever virus were isolated from human blood samples, and 26 strains from batches of mosquitoes. We called this epidemic "intermediate sylvatic epidemic". The epidemic quickly decreased in the sylvatic area, owing to climatic conditions. A mass campaign of vaccinations prevented it from spreading to near urban centres. On this particular case, the thermostability on field of the vaccine 17D provided by the Institute Pasteur of Dakar was proved to be effective.

[Research on malaria vaccine]. / Perspectives de recherche sur la vaccination antipaludique.

Malaria is an important public health problem in developing countries. The production of a good vaccine needs a better knowledge of different mechanisms which control the immune system. Results from donors show a higher frequency of antigens HLA: A2, B35, CW4, CW6, DRW52, DQW1 and DQW3. The lymphoproliferation in vitro of mononuclear cells, T cells and CD4+ and CD8+ subsets T cells with merozoite extracts is not so clear to establish a correlation between HLA phenotypes and T cells response.

[Use of an apoptosis test in the biological follow up of patients infected with HIV]. / Utilisation du test d'apoptose dans le suivi biologique de sujets infectés par le VIH.

Among biological parameters, spontaneous apoptosis has been studied in lymphocyte culture of HIV seropositive patients. Apoptosis seems to be related with CD4+ deletion.

[Macrophage activation and Mycobacterium leprae: effect of interferon gamma on the production of oxygen free radicals by phagocytic cells]. / Activation macrophagique et Mycobacterium leprae: action de l'interféron gamma sur la production de radicaux oxygénés libres (R.O.L.) des cellules phagocytaires.

Activation of the respiratory metabolic channel (F.O.R.), responsible in part for the bactericidal effect, was measured in vitro by a chemoluminescence test on circulating phagocytes. All mycobacteria tested, except for Mycobacterium leprae, induced a significant response. Its effect on lepromatous leprosy pathology is a subject for discussion.