Estimation of biofilm, proteinase & phospholipase production of the Candida species isolated from the oropharyngeal samples in HIV-infected patients.

BACKGROUND & OBJECTIVES: Candida, the most common opportunistic infection in acquired immunodeficiency syndrome (AIDS), attributes its pathogenicity to its virulence factors, mainly the biofilms, the proteinases and the phospholipases. There is a significant interplay of these factors during the HIV infection. This study was aimed to estimate the biofilm, proteinase and phospholipase production in Candida species isolated from the oropharyngeal samples in the HIV-infected patients. METHODS: A total of 126 consecutive HIV-positive patients were screened for Candida growth using oropharyngeal swabs. Identification was done by Gram staining, germ tube test, chlamydospore identification, chromagar and biochemical tests on Vitek 2. Biofilm production was observed on Sabouraud's dextrose broth with glucose, phospholipase production in egg yolk agar medium and proteinase production in bovine serum albumin agar medium. RESULTS: Of a total of 126 patients, 53 (42.06%) showed Candida growth: Candida albicans (n=46, 86.8%) was most common followed by the non-albicans Candida (NAC) (n=7, 13.93%). Of a total 33 (62.3%) biofilm positive isolates, significant production was observed in the NAC species (P <0.05). C. albicans reported the highest phospholipase (n=37/41, 90.24%) and proteinase (n=37/43, 86%) activities in a total of 41 (77%) phospholipase positive and 43 (81.1%) proteinase positive isolates. INTERPRETATION & CONCLUSIONS: Although C. albicans was the most common Candida species identified in HIV positive patients, the emergence of NAC was of special concern. Virulence factors such as biofilms, proteinases and phospholipases were noted in both these groups. Further research is required for better understanding of the pathogenic role of Candida species so as to aid in therapeutic interventions.

Phase II trial of imatinib in AIDS-associated Kaposi's sarcoma: AIDS Malignancy Consortium Protocol 042.

PURPOSE: Kaposi's sarcoma (KS) is a disease of multifocal vascular proliferation that requires infection with KS herpes virus (KSHV/HHV-8). Activation of the c-kit and platelet-derived growth factor (PDGF) receptors by autocrine/paracrine mechanisms follows endothelial cell KSHV infection. In a pilot study, imatinib, a c-kit/PDGF-receptor inhibitor, induced partial regression of AIDS-associated KS (AIDS-KS) in five of 10 patients. PATIENTS AND METHODS: This multicenter phase II study was designed to estimate the response rate to imatinib in AIDS-KS. Secondary objectives included investigation of predictors of response and imatinib pharmacokinetics in patients on antiretrovirals. Patients received imatinib 400 mg/day by mouth for up to 12 months with dose escalation up to 600 mg/day at 3 months if their disease was stable. RESULTS: Thirty patients were treated at 12 AIDS Malignancy Consortium sites. Ten patients (33.3%) achieved partial response, six (20%) had stable disease, and seven (23.3%) exhibited KS progression. Nine patients completed 52 weeks of imatinib therapy. The median treatment duration was 22.5 weeks. Only five patients (16.7%) discontinued therapy owing to adverse events. Antiretroviral regimens did not significantly alter imatinib metabolism. Activating mutations in PDGF-R and c-kit were not found at baseline or at disease progression. We found no correlation with response with changes in any of the candidate cytokines. CONCLUSION: Imatinib has activity in AIDS-KS. Pharmacokinetic interactions with antiretroviral drugs did not correlate with toxicity. Thirty percent of patients showed long-term clinical benefit and remained on imatinib for the entire year. These results suggest imatinib is well tolerated and may be an alternative therapy for some patients with AIDS-KS.

Cryptococcal pleuritis containing a high level of adenosine deaminase in a patient with AIDS: a case report.

Cryptococcal infection is the 4th most common opportunistic infection in patients with acquired immune deficiency syndrome (AIDS). Although pleural effusion alone is an unusual presentation, we present a case of cryptococcal pleuritis in an AIDS patient which was initially difficult to discriminate from tuberculous pleuritis because of the high level of pleural adenosine deaminase (ADA). Cryptococcus neoformans was detected in the culture of the pleural effusion after the initiation of antituberculous treatment. High levels of ADA in the pleural fluid can be observed in patients with cryptococcal pleuritis, and longer incubation of pleural fluid should be performed in all patients who present with pleuritis associated with a high ADA level as the only significant finding.

Extracellular enzymatic activities in Cryptococcus neoformans strains isolated from AIDS patients in different countries

Trescientas diez cepas de Cryptococcus neoformans aisladas de pacientes con sida de cinco países (151 de Brasil, 23 de Italia, 28 de España, 104 de Tailandia y cuatro de Turquía) fueron analizadas con el test API-ZYM para detectar su actividad enzimática extracelular. Las enzimas esterasa (C4) (nº3), esterasa lipasa (C8)(nº4), leucina arilamidasa (nº6) y fosfatasa ácida (nº11) resultaron positivas en la mayoría de las cepas (más del 95%). Estas enzimas podrían considerarse como una herramienta útil, no solo para la identificación de C. neoformans, sino también estudiar factores de virulencia y realizar estudios epidemiológicos. Es también interesante el alto porcentaje de cepas positivas a la alfa y beta-glucosidada presente en todos los países. El serotipo A fue el más frecuente en todos los países, excepto en Italia, donde el serotipo D fue predominante. Se necesitan más estudios para establecer una clara correlación entre el perfil API-ZYM y el serotipo de C. neoformans(AU)

Three hundred and ten Cryptococcus neoformans strains isolated from AIDS patients in five different countries (151 from Brazil, 23 from Italy, 28 from Spain, 104 from Thailand and four from Turkey) were tested by the API-ZYM kit to detect their extracellular enzymatic activity. The enzymes esterase (C4) (no 3), esterase lipase (C8) (no 4), leucine arylamidase (no 6) and acid phosphatase (no 11) were commonly positive in most of the strains (more than 95%). These enzymes could be considered a useful tool not only for C. neoformans identification, but in particular for their possible relationship to new C. neoformans virulence factors and also for epidemiological research. Interestingly, it is also the high positive percentage of alpha-glucosidase and beta-glucosidase detected in all isolates. The serotype A was the most predominant serotype in all countries, except for Italy where the serotype D was predominant. Further studies are needed to draw a clear correlation between the API-ZYM profile and serotype(AU)

Matrix metalloproteinases, their production by monocytes and macrophages and their potential role in HIV-related diseases.

Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases that are a subfamily of metzincins. Matrix metalloproteinases are responsible for much of the turnover of extra-cellular matrix components and are key to a wide range of processes including tissue remodeling and release of biological factors. Imbalance between the MMPs and endogenous tissue inhibitors of metalloproteinases (TIMPs) can result in dysregulation of many biologic processes and lead to the development of malignancy, cardiovascular disease, and autoimmune and inflammatory disorders. MMP production by monocyte/macrophages is dependent on the cell type, state of differentiation, and/or level of activation and whether they are infected, e.g., by HIV-1. MMP expression by HIV-1 infected monocytes and macrophages may alter cellular trafficking and contribute to HIV-associated pathology such as HIV-associated dementia (HAD). This review will provide a classification of the MMP super-family with particular reference to those produced by monocyte/macrophages, describe their regulation and function within the immune system, and indicate their possible roles in the pathogenesis of disease, including HIV-associated dementia.

Extracellular enzymatic activities in Cryptococcus neoformans strains isolated from AIDS patients in different countries.

Three hundred and ten Cryptococcus neoformans strains isolated from AIDS patients in five different countries (151 from Brazil, 23 from Italy, 28 from Spain, 104 from Thailand and four from Turkey) were tested by the API-ZYM kit to detect their extracellular enzymatic activity. The enzymes esterase (C4) (no 3), esterase lipase (C8) (no 4), leucine arylamidase (no 6) and acid phosphatase (no 11) were commonly positive in most of the strains (more than 95%). These enzymes could be considered a useful tool not only for C. neoformans identification, but in particular for their possible relationship to new C. neoformans virulence factors and also for epidemiological research. Interestingly, it is also the high positive percentage of alpha-glucosidase and beta-glucosidase detected in all isolates. The serotype A was the most predominant serotype in all countries, except for Italy where the serotype D was predominant. Further studies are needed to draw a clear correlation between the API-ZYM profile and serotype.

Role for Raf in the entry of viruses associated with AIDS (review).

The biology of acquired immune deficiency (AIDS) is yet to be completely understood partly because it is complicated by the manifestation of various viral infections and associated pathogenesis. Virus entry into target cells is a key step in the virus replication cycle which is characterized by intricate and complex interactions between virus and host cells. Analyses of virus entry are always hampered to some extent due to the inability to mimic in vivo conditions. Emphasis has been placed on understanding what the virus does during the entry process; for example the signaling it mediates during entry, or identifying the cellular receptors with which the virus interact. Often, the role of the cellular environment that is critical for the complex process of virus uptake has taken a back stage. Interestingly, most of the viruses associated with AIDS cause tumors. In a recently concluded study, we identified a role for intracellular oncogenic (Raf) signaling in human herpesvirus-8 (HHV-8/KSHV) infection of target cells. In this review we present an update on entry of various viruses commonly associated with AIDS and yet another novel way of analyzing virus entry.

Impact of amphotericin B on the cytochrome P450 system in HIV-infected patients.

OBJECTIVE: To investigate whether cytochrome P450-dependent enzymes are influenced by amphotericin B (Am-B) during the treatment of Candida oesophagitis in HIV-infected patients. METHODS: Twelve HIV-infected, antiretroviral-naive patients (CDC/WHO stage C3) with Candida oesophagitits were enrolled into a prospective clinical trial. The patients were treated with Am-B (0.4 mg/kg body weight) for two weeks. At baseline and after Am-B therapy the clearance of antipyrine and its metabolites were investigated by high-performance liquid chromatography. In addition, the urinary excretion of 6-beta-hydroxycortisol and 17-hydroxycorticosteroids was assessed by means of a radioimmunoassay. RESULTS: The following significant changes were observed after Am-B treatment (P < 0.01): increase of antipyrine half-life (12.4 h vs 16.8 h) and the area under the plasma concentration-time curve (27.9 mg min/ml vs 38.1 mg min/ml); decrease of the total body clearance (61.2 ml/min vs 43.7 ml/min); decrease of the renal clearance of antipyrine metabolites - norantipyrine (7.45 ml/min vs 5.31 ml/min), 4-hydroxyantipyrine (15.4 ml/min vs 10.3 ml/min), hydroxymethylantipyrine (4.31 ml/min vs 3.65 ml/min); decrease of urinary 6-beta-hydroxycortisol excretion (453 microg/24h vs 298 microg/24h) and the ratio of 6-beta-hydroycortisol to 17-hydroxycorticosteroids (8.8% vs 6.4%). CONCLUSIONS: Our data indicate that Am-B therapy has an inhibitory effect on cytochrome P450-dependent enzymes in HIV-infected patients. These results are of particular significance for HIV-infected patients who are concomitantly treated with drugs that are predominantly metabolised in the liver. A careful drug monitoring system seems advisable, especially for proteinase inhibitor experienced HIV-1-infected subjects.

Effects of multiple virus coinfections on disease progression in HIV-positive patients.

OBJECTIVE: Since virus infections in AIDS patients are mostly inevitable and as they frequently cause disease deterioration and therapeutic failures, a comprehensive investigation was made of the influence of the coinfections of 9 well-known viruses on disease progression in patients infected with human immunodeficiency virus type 1 (HIV). METHODS: A cross-sectional study of 62 HIV-positive patients was conducted to correlate the prevalence rates for the 9 viruses with the alanine aminotransferase (ALT) levels and CD4 cell counts of the patients. RESULTS: The rates of HIV-positive patients infected with the 9 viruses are significantly higher than those of the control groups. Furthermore, almost one third of the patients in the studied group was coinfected with transfusion-transmitted virus (TTV) and manifested significantly higher ALT levels (p = 0.020), and these were raised further if coinfection with TTV and human hepatitis C virus had occurred (p = 0.010). By analyzing CD4 cell counts, the only significant effect on AIDS progression which could be detected was coinfection with human herpesvirus 8. CONCLUSION: This result confirmed that immune-suppressed persons are more vulnerable to common virus infections. Unlike hepatitis B or C virus, TTV seems to accelerate the progression of chronic hepatitis in HIV-infected patients.

Serum LDH level as a clue to the diagnosis of histoplasmosis.

The purpose of this study was to determine whether serum lactate dehydrogenase (LDH) level could be used as an adjunct clinical marker to differentiate between histoplasmosis and Pneumocystis carinii pneumonia (PCP). In a retrospective, case-controlled study, 30 patients with a diagnosis of histoplasmosis (all but 1 with disseminated disease) were compared with 120 patients with PCP (33 patients with definitive PCP, 87 with presumed PCP). Groups were matched for CD4+ lymphocyte counts, sex, and year of diagnosis. The mean LDH level for patients with histoplasmosis was 1068 +/- 197 IU/L; for PCP, it was 375 +/- 23. An LDH level of more than 450 IU/L was 9.33 times more likely to be associated with a diagnosis of histoplasmosis than with PCP (odds ratio [OR], 9.33; 95% confidence interval [CI], 3.50-25.47; P < .01), and an LDH level of more than 600 IU/L was 9.41 times more likely to be so (OR, 9.41; 95% CI, 3.43-26.31; P < .01). An LDH level of 450 IU/L or greater had a sensitivity and specificity of 70% and 80%, respectively; a value of 600 IU/L or greater had sensitivity and specificity of 50% and 89%. Thus, serum LDH levels of 600 IU/L or greater are suggestive of histoplasmosis rather than PCP in appropriate clinical settings. Serum LDH may serve as an adjunct laboratory marker in the diagnosis of histoplasmosis. Elevated levels may prompt the physician to look for a diagnosis other than PCP early in the course of the illness.

The association of serum lactate dehydrogenase level with selected opportunistic infections and HIV progression.

BACKGROUND: The purpose of this study was to determine the association of serum lactate dehydrogenase (LDH) levels with certain opportunistic infection and to determine an association between LDH levels and CD4+ lymphocyte counts. METHOD: We studied 352 patients retrospectively with HIV infection and one of the following infections: histoplasmosis; toxoplasmosis; tuberculosis (pulmonary and disseminated); bacterial pneumonia; Pneumocystis carinii pneumonia. Demographic and clinical data were obtained from the Adult Spectrum of Diseases (ASD) database in New Orleans. Bivariate and multivariate analysis were used to determine the association between LDH levels and opportunistic infections and CD4+ lymphocyte counts. RESULTS: Patients with a serum LDH level <225 IU/L had a mean CD4+ lymphocyte count of 159/dl (SE 19.3) as compared to patients with a serum LDH level > or =225 IU/L, who had a mean CD4+ lymphocyte count of 58/dl (SE 6.9) (P<0.01). Non-Caucasian race, a diagnosis of histoplasmosis, disseminated tuberculosis or Pneumocystis carinii pneumonia, and CD4+ lymphocyte count were significantly associated with a serum LDH level > or =225 IU/L in the bivariate analysis. In a multivariate analysis, after controlling for race and CD4+ lymphocyte count, the only diagnoses that were significantly associated with the serum LDH level were definitive Pneumocystis carinii pneumonia and toxoplasmosis. Having a higher LDH level was not associated with early mortality. CONCLUSIONS: Although not diagnostic, serum LDH levels could be used as an adjunctive marker in certain opportunistic infections. There is an inverse relationship between serum LDH levels and CD4+ lymphocyte counts in this group.

Initial treatment with amphotericin B plus rifampin in the acute treatment of cryptococcal meningitis in aids.

The result of initial treatment with amphotericin B (0.7 mg/kg/day) plus rifampin (600 mg/day) for 2 weeks, followed by fluconazole (400 mg/day) for 8 weeks in the acute treatment of cryptococcal meningitis in AIDS is reported. There were 10 patients in the study: at 2 weeks, all had made a clinical response and cerebrospinal fluid was sterile in 4 patients; at 10 weeks, all had negative cerebrospinal fluid cultures. Serious side effects were not detected.

Increased activity of matrix metalloproteinases in the cerebrospinal fluid of patients with HIV-associated neurological diseases.

Matrix metalloproteinases (MMPs) have been identified as mediators of brain injury in HIV-associated neurological diseases. The activity of the 72 kDa gelatinase A (MMP-2) and 92 kDa gelatinase B (MMP-9) was detected by zymography in the cerebrospinal fluid (CSF) of 138 HIV-infected patients (40 with AIDS dementia, 83 with brain opportunistic infections and 15 neurologically asymptomatic), 26 HIV-seronegative individuals with inflammatory neurological diseases (IND) and 12 HIV-seronegative subjects with noninflammatory neurological diseases (NIND). MMP-2 was present in all CSF samples from HIV-seropositive and HIV-seronegative individuals, including those of subjects with NIND. On the contrary, MMP-9 was absent in the CSF of NIND controls, whereas the activity of this MMP was found in the 77 - 100% of CSF samples from HIV-infected patients, including those with HIV dementia, central nervous system (CNS) opportunistic infections or neurologically asymptomatic subjects. The highest levels of MMP-9 were found in the CSF of patients with cryptococcosis, cytomegalovirus encephalitis and tuberculous meningitis and were comparable with those found in the CSF of HIV-negative patients with multiple sclerosis or meningitis. A significant correlation between CSF MMP-9 activity and CSF cell count was found only in patients with HIV dementia. The increased CSF activity of MMPs capable to degrade components of the extracellular matrix of blood-brain barrier may contribute to the transendothelial migration of virus-infected cells into the CNS and development of HIV-associated neurologic damage.

Elevated adenosine deaminase activity in patients with HIV and tuberculous peritonitis.

OBJECTIVE: To evaluate the diagnostic potential of the ADA(T), ADA isoenzymes (ADA1 and ADA2) and the interferon-gamma (IFN-gamma) test in HIV-seropositive patients with tuberculous peritonitis. METHODS: Ascitic ADA(T), ADA1, ADA2 and IFN-gamma were prospectively evaluated in HIV-seronegative patients with tuberculous peritonitis (n = 17), HIV-seropositive patients with tuberculous peritonitis (n = 6) and in patients with cirrhosis (n = 22) and malignancy (n = 5). RESULTS: ADA(T) and ADA2 isoenzyme activities of HIV-seronegative (ADA(T) = 109 U/l; ADA2 = 94 U/l) and HIV-seropositive (ADA(T) = 109.5 U/l; ADA2 = 95.5 U/l) patients with tuberculous peritonitis, respectively, were significantly different (P < 0.001) from patients with cirrhosis (ADA(T) = 10.5 U/l; ADA2 = 8 U/l) and malignancy (ADA(T) = 13 U/l; ADA2 = 11 U/l). There was no significant difference in ADA(T) and ADA2 activities between HIV-seropositive and seronegative patients with tuberculous peritonitis. There was no significant correlation between ADA, its isoenzymes and IFN-gamma. CONCLUSIONS: The diagnosis of tuberculous peritonitis can be made by a sensitive, relatively non-invasive procedure in both HIV-seronegative and seropositive patients with minimal risk to the patient and the investigator. The diagnostic value of ADA(T) is not enhanced by measuring ADA isoenzymes or IFN-gamma.

High aspartyl proteinase production and vaginitis in human immunodeficiency virus-infected women.

Vaginal isolates of Candida albicans from human immunodeficiency virus-positive (HIV+) and HIV- women with or without candidal vaginitis were examined for secretory aspartyl proteinase (Sap) production in vitro and in vivo and for the possible correlation of Sap production with pathology and antimycotic susceptibility in vitro. HIV+ women with candidal vaginitis were infected by strains of C. albicans showing significantly higher levels of Sap, a virulence enzyme, than strains isolated from HIV+, C. albicans carrier subjects and HIV- subjects with vaginitis. The greater production of Sap in vitro was paralleled by greater amounts of Sap in the vaginal fluids of infected subjects. In an estrogen-dependent, rat vaginitis model, a strain of C. albicans producing a high level of Sap that was isolated from an HIV+ woman with vaginitis was more pathogenic than a strain of C. albicans that was isolated primarily from an HIV-, Candida carrier. In the same model, pepstatin A, a strong Sap inhibitor, exerted a strong curative effect on experimental vaginitis. No correlation was found between Sap production and antimycotic susceptibility, as most of the isolates were fully susceptible to fluconazole, itraconazole, and other antimycotics, regardless of their source (subjects infected with strains producing high or low levels of Sap, subjects with vaginitis or carrier subjects, or subjects with or without HIV). Thus, high Sap production is associated with virulence of C. albicans but not with fungal resistance to fluconazole in HIV-infected subjects, and Sap is a potentially new therapeutic target in candidal vaginitis.

Markedly elevated serum lactate dehydrogenase levels are a clue to the diagnosis of disseminated histoplasmosis in patients with AIDS.

Disseminated histoplasmosis is a common late manifestation of AIDS, but the diagnosis may be unsuspected in some patients because the clinical presentation of histoplasmosis may mimic other opportunistic infections. High serum lactate dehydrogenase (LDH) levels have been associated with disseminated histoplasmosis. We therefore evaluated whether markedly increased LDH levels were useful for making a diagnosis of disseminated histoplasmosis by comparing admission LDH levels for 15 patients with culture-proven disseminated histoplasmosis with those for 30 patients with advanced AIDS who were admitted to the hospital for evaluation of pulmonary infiltrates and fever. The mean admission LDH level in patients with disseminated histoplasmosis was 1,356 IU/L (range, 145-5,410 IU) whereas it was 332 (range, 77-832 IU) in the patients with other pulmonary processes. Admission LDH levels were >600 IU in 11 (73%) of the 15 patients with disseminated histoplasmosis vs. 3 (10%) of controls (P < .001). We conclude that markedly elevated admission LDH levels may be a clinical clue to the diagnosis of disseminated histoplasmosis in patients with AIDS.

Utility of lactate dehydrogenase vs radiographic severity in the differential diagnosis of Pneumocystis carinii pneumonia.

STUDY OBJECTIVES: In patients with HIV infection, serum lactate dehydrogenase (LDH) level is commonly stated to be more elevated in Pneumocystis carinii pneumonia (PCP) than in non-PCP. We hypothesized that LDH level reflects radiographic extent and severity of pneumonia rather than P carinii infection specifically and therefore is not useful in the differential diagnosis of lung infections in AIDS. DESIGN: We compared radiographic features and LDH values in 93 sequential patients with HIV infection and a new hospital admission for pneumonia (53 PCP and 40 non-PCP) after excluding all patients with other potential causes for elevated LDH levels. The chest radiograph was graded using a quantitative scale (0 to 24) to assess radiographic extent and severity of pneumonia by two independent observers in blinded fashion. The relationship between radiographic score and hospital admission LDH level was analyzed by linear regression and Bayesian analysis was applied to different LDH ranges to calculate the clinical value of LDH measurements. SETTING: Tertiary care teaching hospital and regional AIDS referral center. RESULTS: Mean LDH level was higher in the PCP group (1.217 +/- 88 U/L compared with 776 +/- 55 U/L; p < 0.001), as was mean radiographic score (12.4 +/- 0.6 for PCP compared with 6.3 +/- 0.5 for non-PCP; p < 0.001). For the whole sample of 93, LDH level was significantly related to chest radiographic score (r = 0.43, p < 0.0001). Significant overlap occurred between the two groups at all levels of LDH such that no cutoff level could be established that impacted significantly on posttest probability of PCP, whereas a radiographic score of > 12 yielded a 96% posttest probability of PCP. CONCLUSIONS: Serum LDH level reflects the degree of radiographic abnormality and is elevated in both PCP and non-PCP pneumonia to an extent that limits its utility in differentiating the two processes in hospitalized patients. The extent of radiographic involvement more clearly distinguishes the two conditions.

Apoptosis of human monocytes/macrophages in Mycobacterium tuberculosis infection.

Tuberculosis (TB) is still a major health problem, both as a single disease entity and as a cofactor in AIDS. The interaction between macrophage and Mycobacterium tuberculosis (MTB) is a critical step in the establishment of an early chronic infection. This study analyses the capacity of MTB to induce apoptosis in cells obtained by broncho-alveolar lavage (BAL) from patients with reactive pulmonary tuberculosis and from AIDS patients with disseminated pulmonary tuberculosis. Apoptosis was increased three-fold in BAL cells obtained from patients with pulmonary tuberculosis and even more markedly in alveolar macrophages of MTB-infected AIDS patients, compared with controls. Apoptosis was analysed and characterized by propidium iodide (PI) incorporation, terminal deoxy transferase (TDT)-mediated dUTP-biotin nick end labelling (TUNEL), and tissue transglutaminase (tTG) expression. The MTB-macrophage interaction was also investigated in vitro by infecting monocyte-derived macrophages (MDM) with MTB (virulent strain H37Rv). The induction of apoptosis by MTB required viable bacteria, was dose-dependent, and was restricted to H37Rv. Infection with either Mycobacterium avium complex (MAC) or HIV-1 and treatment with heat-killed MTB failed to induce apoptosis.