Clinical and immunological aspects of HIV infection in drug addicts
Clinic of Infectious Disease, Institute of Internal Medicine, Infectious Disease and Immunopathology, University of Milan, Milan 20157, ItalyClinical Immunology and Immunopathology 02/1989; 50(1). DOI: 10.1016/0090-1229(89)90124-4
Intravenous drug users (IVDUs) account for more than 64% of the total AIDS cases in Italy. The IVDUs' seropositivity rate is >70% in Milan and >50% in the main cities of Italy. The first evidence of seropositivity in this population dates back to 1979. In a cohort study performed in Milan the rate of progression to overt AIDS among IVDUs was 6% in 3 years (1984–1987). At presentation, more than 75% of the subjects had CD4+ cell counts higher than 400/mm3 (mean 631, median 528, mode 465). These values are significantly higher than those observed in the same population in New York, the only American city with HIV-infection spread comparable to that observed in Milan. The probability of having CD4+ cell counts lower than 400, 300, and 200/mm3 in relation to the length of follow-up was, respectively, 50, 40, and 2% after 36 months from presentation. At the same end point, subjects presenting less than 400 CD4+ cells at entry had 30% probability of falling under 200 cell/mm3. The pattern of CD4+ cells, as much as the low percentage of yearly progression to overt AIDS, is probably related to the recent, even if rapid, spread of infection among IVDUs in Italy. The clinical features of overt AIDS present some differences between IVDUs and other at-risk groups. Among U.S. IVDUs with AIDS, Kaposi's sarcoma is infrequent (2.9% vs 27.7% in homosexual men) while mycotic infections such as deep candidiasis and cryptococcosis are significantly more frequent. The same pattern has been observed in our case file in Milan: esophageal candidiasis represents the most frequent cause of diagnosis of overt AIDS. Mycotic infections, overall, are more frequent than in U.S. IVDUs. The increased rate of mycotic infections among IVDUs might be justified by altered functions of nonspecific immunity, such as PMNL killing and phagocytosis of Candida albicans spores, impaired in HIV-infected IVDUs, but generally normal in infected subjects belonging to the other at-risk groups.
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ABSTRACT: Analysis of functional properties of natural killer cells displayed in reactions of natural cytotoxicity and noncytotoxic regulatory intercellular interactions suggests that this population of lymphocytes is involved in endogenous biological retranslation. In the immune system, retranslation is the production of regulatory immunoactive cytokines by a cell, cellular complex, or functional complex. The substances produced are identical to those affecting these structures. Various forms of endogenous biological retranslation in humans and higher animals, as well as its phylogenetic and ontogenetic manifestations (on the basis of noncytotoxic regulatory interactions of natural killer cells with cells of lymphoid or nonlymphoid nature) during evolution of the complex of immunobiological surveillance are considered. The axiomatic basis of retranslation realized through the system of natural cytotoxicity was established. Prospects for application of the methodology of endogenous biological retranslation to experimental and clinical studies of functioning of natural killer cells are considered.
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ABSTRACT: Increasing numbers of patients with diagnosed HIV infection are presenting to inner-city emergency departments. Unfortunately, there is little information available on the characteristics and emergency clinical problems of HIV-infected patients to guide physicians in patient care and strategies for resource use. Preliminary data from an on-going investigation revealed that there were 254 emergency visits (1.8% of total) by 164 patients with known HIV infection during the four-month period of March to June 1988. Only 171 visits (62%) were likely related to patients' underlying HIV infection. Nine percent of IV drug users (IVDUs) carried a diagnosis of AIDS before presentation compared with 68% of patients who were homosexual or bisexual. Fifty-five patients (21.7%) presented with their first known complication of HIV. Among the 140 risks from patients previously considered asymptomatic, those with homosexual or bisexual risk were 3.6-fold more likely to present with a first-time complication of HIV than were IVDUs. HIV-infected patients were twice as likely to have inadequate insurance compared with a sample of ED seronegative controls. Of the 130 risks by IVDUs, 85% were without adequate insurance coverage compared with 56% of the 91 patient risks from homosexual or bisexuals (P less than .05). Generally, patient presentations did not imply an obvious diagnosis; vague constitutional complaints were the most common (42%). Preliminary interpretation of the data is that IVDUs use emergency services as a routine source of care. Because IVDUs probably represent those with more recent infection and HIV infection continues to spread unabated in this risk group, we can expect increasing numbers of patients to present to EDs with symptomatic HIV infection in the future.(ABSTRACT TRUNCATED AT 250 WORDS)
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ABSTRACT: A data-based mathematical model was formulated to assess the epidemiological consequences of heterosexual, intravenous drug use (IVDU) and perinatal transmission in New York City (NYC). The model was analysed to clarify the relationship between heterosexual and IVDU transmission and to provide qualitative and quantitative insights into the HIV epidemic in NYC. The results demonstrated the significance of the dynamic interaction of heterosexual and IVDU transmission. Scenario analysis of the model was used to suggest a new explanation for the stabilization of the seroprevalence level that has been observed in the NYC IVDU community; the proposed explanation does not rely upon any IVDU or sexual behavioural changes. Gender-specific risks of heterosexual transmission in IVDUs were also explored by scenario analysis. The results showed that the effect of the heterosexual transmission risk factor on increasing the risk of HIV infection depends upon the level of IVDU. The model was used to predict future numbers of adult and pediatric AIDS cases; a sensitivity analysis of the model showed that the confidence intervals on these prediction estimates were extremely wide. This prediction variability was due to the uncertainty in estimating the values of the models' thirty variables (twenty biological-behavioural transmission parameters and the initial sizes of ten subgroups). However, the sensitivity analysis revealed that only a few key variables were significant in contributing to the AIDS case prediction variability; partial rank correlation coefficients were calculated and used to identify and to rank the importance of these key variables. The results suggest that long-term precise estimates of the future number of AIDS cases will only be possible once the values of these key variables have been evaluated accurately.
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