High frequency of subclinical Leishmania infection among HIV-infected patients living in the endemic areas of visceral leishmaniasis in Fars province,southern Iran

Parasitology Research - Visceral leishmaniasis (VL) is a major health concern in patients with HIV infection in endemic areas of VL. In these areas, a substantial number of infected individuals are...     

Delayed-type hypersensitivity and cell-mediated immunity in the pathogenesis of tuberculosis.

It is widely believed that cell-mediated immunity and the associated ability of macrophages to destroy or inhibit the bacillus are all that is required to control pulmonary tuberculosis. However, although cell-mediated immunity is a major host defense against the tubercle bacillus, it is fully effective only in one of the four stages of the disease. Here, Arthur Dannenberg describes the entire pathogenesis of tuberculosis, with illustrations from the rabbit model of M.B. Lurie. In addition, he documents that the delayed-type hypersensitivity reaction (producing tissue necrosis) greatly benefits the host by arresting the logarithmic growth of bacilli within immature macrophages.     

Non-AIDS-defining malignancies among HIV-infected patients in the highly active antiretroviral therapy era

In the highly active antiretroviral therapy (HAART) era, the incidence of AIDS-defining malignancies (ADMs) has declined significantly. On the other hand, the incidence of other malignancies not known to be associated with immunosuppression (non-ADMs) has not changed and remains significantly higher than in the general population. Some recent controlled studies even suggest that the incidence of selected non-ADMs has increased in the HAART era. These trends warrant a high index of suspicion for malignancies among HIV care providers and a renewed focus on understanding the mechanisms underlying the increased rates. Potential explanations for the higher non-ADM rates include longer survival of patients with HIV on HAART, with only partial immune recovery achieved in most patients; high incidence of human papillomavirus, Epstein-Barr virus, and hepatitis C virus coinfection in patients with HIV infection; and potential oncogenicity of long-term HIV infection or of long-term HAART.     

Delayed-type hypersensitivity to rabies virus in mice: assay of active or passive sensitization by the footpad test.

With a purified beta-propiolactone-inactivated rabies virus, a significant increase in footpad swelling was elicited in normal or in BCG-pretreated mice after immunization with varying doses of rabies vaccine. These footpad reactions were shown to peak at 24 h and to be associated with an infiltration of newly formed blood monocytes demonstrated by histology and [125I]deoxyuridine labeling. A relationship between the lymphoproliferation and the degree of sensitization is described, and the susceptibility to cyclophosphamide treatment is also examined. Adoptive transfer of specific reactivity to normal recipient mice with immune lymphoid cells, but not with immune serum, was demonstrated, and the results represent another argument for a cell-mediated immunological mechanism.     

Lipids,metabolic syndrome,and risk factors for future cardiovascular disease among HIV-infected patients

The availability of potent combination antiretroviral therapy has changed the long-term prognosis for people living with HIV/AIDS. There is increasing concern, however, about the effect of HIV therapy on lipid disorders and subsequent development of coronary artery disease. Virtually all classes of antiretroviral drugs have been associated with some aspect of atherogenic changes in the lipid profiles. This article reviews the current literature on HIV-associated dyslipidemias and the metabolic syndrome, their potential effect on future coronary heart disease, and reviews strategies for management.     

Relationships among differentiated T-cell subpopulations. I. Dissociated development of tuberculin type hypersensitivity, Jones-Mote type hypersensitivity and activation of helper function.

Relationships among tuberculin type hypersensitivity, Jones-Mote type hypersensitivity and activation of helper T cells were studied in AKR mice by means of footpad reaction, migration inhibition test and antibody production against the trinitrophenyl group. (1) Immunization with SRBC in saline, Freund's incomplete adjuvant (FIA) or complete adjuvant (FCA) and fixed-SRBC (FRBC) in FIA- or FCA-induced delayed hypersensitivity as demonstrated by footpad swelling. (2) Migration inhibition was positive in the groups immunized with SRBC or FRBC in FCA, but negative in those immunized with SRBC in saline or FIA or FRBC in FIA. This may suggest that the former has to be assigned to tuberculin type and the latter to Jones-Mote type. (3) Both pre-treatment with BCG and with cyclophosphamide (CY) augmented delayed footpad reaction in the mice immunized with SRBC in saline. However, migration inhibition was positive only in the group pre-treated with BCG. BCG may convert the reaction from Jones-Mote type to tuberculin type, while CY may augment the reaction of Jones-Mote type. (4) FRBC in saline scarcely induced delayed footpad reaction, whereas they activated helper function efficiently. Thus, three types of immunological phenomena attributable to the functions of T cells may depend upon distinct subpopulations of differentiated T cells which are raised by different methods of immunization.     

Safety, tolerability, pharmacokinetics, and efficacy of an interleukin-2 agonist among HIV-infected patients receiving highly active antiretroviral therapy.

We sought to determine the safety, maximum tolerated dose, optimal dose, and preliminary dose efficacy of intermittent subcutaneously (s.c.) administered BAY 50-4798 among patients with HIV infection receiving highly active antiretroviral therapy (HAART) compared with patients receiving HAART alone. A phase I/II randomized, double-blind, dose-escalation study was conducted of the safety, tolerability, pharmacokinetics, and efficacy of s.c. BAY 50-4798 administered to HIV-infected patients already receiving stable HAART. There were no unexpected safety findings in a population of HIV-infected patients receiving HAART plus SC BAY 50-4798 as adjunctive therapy. BAY 50-4798 exhibited nearly dose-proportional pharmacokinetics, and accumulation was minimal during multiple-dose treatment. Limited efficacy data indicated that treatment with BAY 50-4798 caused at least a transient increase in CD4(+) T cell counts in some recipients, particularly at the early time points. In general, this effect appeared to increase with increasing dose. Bay 50-4798 was generally well tolerated across the dose range tested, but a lack of potent, sustained immunologic activity suggests that further optimization of dose and schedule will be necessary.     

Delayed-type hypersensitivity in rabbits. Comparison of the adjuvants dimethyl dioctadecyl ammonium bromide and Freund's complete adjuvant

Injection of rabbits with antigen mixed with the cationic surface-active lipid dimethyl dioctadecyl ammonium bromide (DDA) induced delayed-type hypersensitivity (DH), which could be measured as skin reactions and was confirmed by histology of the skin test sites. 1 week after injection of a conjugate of bovine serum albumine (BSA) with dinitrophenol (DNP30-BSAj) mixed with DDA, DH was detectable in most but not in all rabbits. Similar results were obtained using FCA as adjuvant. The animals treated with the latter adjuvant, however, produced a long-lasting DH (1-3 weeks) complicated by circulating anti-DNP antibodies (Arthus-type reactions). Skin testing with heterologous hapten-carrier complexes revealed that individual rabbits immunized with DNP30-BSA in DDA expressed DH with different reaction patterns, either to hapten, carrier or both. In conclusion, DDA is a useful adjuvant for the induction of a state of pure DH in rabbits. However, not all rabbits do respond, or respond similarly.     

In vitro whole-blood analysis of cellular immunity in patients with active coccidioidomycosis by using the antigen preparation T27K

Measurement of cellular immunity in human coccidioidomycosis has important diagnostic and prognostic implications. The coccidioidin skin test has been the standard for the measurement of this, but it is not available in the United States. We examined the utility of measuring surface expression of CD69 on T lymphocytes in whole blood incubated with the coccidioidal antigen preparation T27K as an alternative to the skin test. Seventy donors with active coccidioidomycosis were studied. The mean fluorescent intensity (MFI) of CD69 expression on CD3 lymphocytes in response to T27K was 28.61 +/- 1.77, significantly greater than the control response of 11.45 +/- 0.78 (P < 0.001). The MFI CD69 response to T27K above that for the control (MFI CD69 above control) was 6.35 +/- 2.18 for seven subjects with disseminated coccidioidomycosis who were studied within 5 months of diagnosis. This was significantly below the value of 20.17 +/- 3.17 for 18 subjects with pulmonary coccidioidomycosis studied within 5 months of diagnosis and the value of 19.58 +/- 2.91 for 27 subjects with disseminated coccidioidomycosis studied after 5 months of diagnosis (for both, P < 0.05). There was an inverse correlation between coccidioidal clinical score and MFI CD69 above control for all 34 subjects with disseminated coccidioidomycosis (r = 0.362; P = 0.036) but not for the 36 subjects with pulmonary disease (r < 0.001; P = 0.993). Among 30 subjects for whom data were available, there was a highly significant association between the MFI CD69 above control and the supernatant concentrations of gamma interferon, interleukin-2 (IL-2), and tumor necrosis factor alpha (for all, P < 0.001), but not for IL-4, IL-5, or IL-10. These data indicate that in vitro assessment of CD69 expression on T lymphocytes by using T27K may be a useful measure of cellular immune response among subjects with active coccidioidomycosis.     

Prevalence of cryptococcosis among HIV-infected patients in Yaounde, Cameroon

Background

Cryptococcus neoformans is encapsulated yeast which causes life-threatening infections in up to 40% of AIDS patients in Africa.

Objective

To investigate the prevalence of cryptococcosis among HIV infected patients in Yaounde.

Methods

In a hospital-based surveillance study of cryptococcosis, the colonization of Cerebrospinal Fluid (CSF), urine and blood sample by C. neoformans was evaluated by direct microscopic examination and culture techniques. Data obtained were then analyzed based on the medical records of the patients.

Results

Among the105 patients sampled for the study, the CD4 counts varied between 31 and 304 lymphocytes/mm³. Direct specimens examination (n= 294) in India ink preparations revealed polysaccharide capsule in 25 (8.5%) of the samples. Upon culture, 29 (9.86 %) samples were positive of C. neoformans (23 from the CSFs and 6 from the urine). All the positive samples were obtained from patients who were not on Antiretroviral Therapy (ART). Meningo-encephalitis symptoms were observed in 13 patients with C. neoformans in CSFs.

Conclusion

This study reveals that cryptococcosis is rife in AIDS patients in Yaounde. Therefore, to minimize the death toll, we recommend that its routine check should be integrated in the management of HIV/AIDS patients.     

High proportion of T-cell systemic non-Hodgkin lymphoma in HIV-infected patients in Lima, Peru

OBJECTIVE: Few reports have described the clinical and pathologic characteristics of HIV-related systemic non-Hodgkin lymphoma (sNHL) in developing countries. We aimed to determine these characteristics from a national HIV reference center in Peru and to evaluate factors associated with survival. METHODS: A retrospective/prospective study of patients with HIV-related sNHL from the Guillermo Almenara General Hospital in Lima, Peru between 1993 and 2004. Clinical characteristics at diagnosis included age, gender, risk behavior, previous AIDS diagnosis, opportunistic diseases, previous highly active antiretroviral therapy, Karnofsky score, origin, clinical stage and B-cell symptoms of sNHL, and CD4 cell count. Cases of sNHL were classified according to the criteria of the World Health Organization. RESULTS: Thirty-three cases were identified (26 male, age range: 38 +/- 10 years). Ten patients (30%) had a prior history of AIDS, 14 (42%) had a Karnofsky score of 相似文献   

Hand skeletal development among Ecuadorians living under conditions of iodine deficiency and endemic goiter.

Hand radiographic assessment has revealed the pattern of skeletal growth and maturation among Ecuadorian Indian villagers where iodine deficiency has resulted in an endemia of goiter and cretinism. This is intended to provide base line information for future attempts to learn about physical impairment among people living under inadequate iodine nutriture.     

Relationship between maternally derived anti-Plasmodium falciparum antibodies and risk of infection and disease in infants living in an area of Liberia, west Africa, in which malaria is highly endemic.

In areas where Plasmodium falciparum is endemic, immunoglobulin G is acquired by the fetus in utero, mainly during the third trimester of pregnancy. The potential protective effect of transferred anti-P. falciparum maternal antibodies was examined in a longitudinal study of 100 infants from birth to 1 year of age. The probability of acquiring a P. falciparum infection and developing an episode of clinical malaria was determined in relation to the P. falciparum-specific antibody level of the infant at birth against P. falciparum schizont antigen or recombinant merozoite surface protein MSP1(19) antigen. The risk of acquiring an episode of clinical malaria increased from birth to 6 months of age, after which it decreased. The overall prevalence of P. falciparum parasitemia was highest (48.9%) in the 6-month-old infants. The age-specific hematocrit value showed the lowest mean value (30.2) from 6 to 9 months, and the spleen rate was the highest (69.8%) at the same age. There was a lower risk of developing an episode of clinical malaria during the first year of life in the infants with high levels of anti-MSP1(19) antibodies at birth. The level of maternally derived overall anti-schizont antigen antibodies did not seem to play a role in the relative risk of developing malaria infection or disease during the first year of life, though the level of specific anti-MSP1(19) antibodies may be associated with protection.     

Prevalence of human T-cell leukemia virus antibody among heterosexuals living in Amsterdam, The Netherlands

To determine the heterosexual spread of human T-cell leukemia virus (HTLV-I) infections, a cohort of 472 individuals with more than 5 heterosexual partners in the 6 months before entry was studied. They were recruited from visitors to the Clinic for Sexually Transmitted Diseases of the Municipal Health Service. Half of the study group was born in the Netherlands, 13% in Surinam or the Dutch Antilles, and 8% in Turkey or Morocco. Seventy percent were involved in commercial sex. Three persons were positive for HTLV-I, with serum antibodies against p19, p24, p28, gp46, and gp61 in Western immunoblot (WIB) and radio-immunoprecipitation assay (RIPA). Two of them originated from Surinam and the third was a Dutch woman. Two other individuals were HIV-positive, 19% had hepatitis B virus (HBV)-markers and 6% Treponema pallidum reacted in the hemagglutination assay (TPHA). It is concluded that HTLV-I circulates in the Surinamese population in Amsterdam and there was no evidence of appreciable heterosexual transmission.     

Fish hypersensitivity. I. In vitro and oral challenge results in fish-allergic patients.

The purpose of this study was to determine whether patients allergic to one fish species can safely eat other fish species. Eleven atopic, food-allergic children and young adults with histories consistent with IgE-mediated fish hypersensitivity were skin prick tested to 10 fish species. Skin prick tests (SPTs) were positive to all 10 fish in eight of the 11 patients, and the remaining three patients had at least two positive fish SPTs. Positive oral challenges occurred to only one fish in seven of the patients, to two fish species in one patient, and to three fish species in two patients. One patient did not react to any of the fish tested. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblot analyses were performed on raw and cooked protein extracts from nine of the 10 fish species used in SPTs. Several protein bands in the raw-fish extracts appeared to denature with cooking and form high molecular weight conglomerates. Immunoblot analyses with sera from documented fish-allergic patients demonstrated specific IgE binding to protein bands from fish to which patients were not clinically allergic, as determined by oral challenge. In ELISA-inhibition assays, the concentration of fish antigen required to achieve 50% inhibition was similar for fish to which the patients were clinically allergic as compared to fish to which they were clinically tolerant. SPT and in vitro evidence of IgE-specific cross-reactivity does not necessarily correlate with symptomatic fish allergy. In addition, these fish-hypersensitive patients were able to consume one or more other fish species without adverse allergic reactions.     

Clonal evolution of CD8+ T-cell expansions in HIV-infected patients on long-term HAART.

HIV-1 continually replicates in spite of long-term highly active anti-retroviral therapy (HAART) and therefore, it is conceivable that the low level, persistent viral activity could continue to stimulate the hosts immune system despite remaining below the detection limit of the current assays. In this study, we performed a longitudinal analysis of the CD8+ T-cell receptor Vbeta repertoire in HAART-treated and untreated HIV patients. HAART-mediated control of viremia, for up to 18 months, did not prevent similar perturbations within the CD8+ Vbeta repertoire in both study groups as defined by CDR3 spectratyping. Oligoclonal Vbeta expansions, with new dominant CDR3 lengths, were observed throughout the study period. Our findings are compatible with antigen-driven CD8+ immune responses to bursts of replication from a continuously changing viral reservoir, regardless of HAART-mediated suppression of HIV-1 viremia.