A 10-year survey of Mycobacterium tuberculosis isolates in Pavia and their drug resistance: a comparison with other Italian reports

A retrospective review was made of the bacteriological and medical records of patients with culture-confirmed pulmonary tuberculosis who attended the IRCCS San Matteo Polyclinic of Pavia, between 1990 and 2000. Altogether, 279 patients were included in the survey: 220 new cases and 59 prior treatment cases. Resistance to at least one drug, and resistance to both isoniazid and rifampicin (MDR) were more common among previously treated patients than among new cases (86.4% vs. 34.1%, and 44% vs. 5.9%, respectively). While the frequency of resistance to any drug showed no variation in the period examined, a trend toward a progressive decrease in the frequency of primary MDR-TB was observed (from 11.9% in 1990-1992 to 1.3% in 1998-2000). The level of resistance observed in our study suggests that all isolates of Mycobacterium tuberculosis should be tested for drug susceptibility, especially when obtained from patients who report a previous episode of the disease.

Plasma viral load concentrations in women and men from different exposure categories and with known duration of HIV infection. I.CO.N.A. Study Group

CONTEXT

According to recent studies, women have lower plasma HIV RNA concentrations than men. However, these studies did not take into account the duration of HIV infection.

OBJECTIVES

To analyze the relationship between viral load and gender among individuals with known date of seroconversion.

SETTING

Sixty infectious disease clinics in Italy.

DESIGN

Cross-sectional analysis of data collected at enrollment in a cohort study.

PARTICIPANTS

Injecting drug users and heterosexual contacts naive to antiretroviral therapy at enrollment (245 men; 170 women).

MAIN OUTCOME MEASURES

Plasma HIV RNA concentrations, measured using quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) or signal amplification b-DNA assays before antiretroviral therapy.

RESULTS

Plasma HIV RNA concentrations were similar by age and exposure category (p =.80 and p =.39, respectively). Median viral load among women was roughly half that of men (p =.002). The association between viral load and gender remained significant after fitting a two-way analysis of variance (p =.03) and after adjusting for CD4 count, modality of HIV transmission, and age at enrollment in a regression model. Viral load was 0.27 log10 copies/ml (95% confidence interval, 0.05-0.40; p =.01) lower in women (i.e., 50% lower in the raw scale).

CONCLUSIONS

Plasma HIV RNA concentrations were found to be lower among women, even when considering the duration of HIV infection. Compared with men, it is possible women should be given highly aggressive antiretroviral therapy at lower HIV-RNA concentrations.

Successful treatment of spleen tuberculosis in a patient with human immunodeficiency virus infection

Tuberculosis in human immunodeficiency virus (HIV)-infected patients may act as a cofactor that accelerates the clinical course of HIV infection, and, indeed, HIV-infected patients with tuberculosis have a reduced survival rate compared to those without tuberculosis. Diagnosis of tuberculosis in HIV-positive patients can be difficult because of nonspecific symptoms and the time required for the identification of mycobacteria by means of culture techniques. Recently, antiretroviral combination therapies have improved the outcome of several acquired immune deficiency syndrome (AIDS)-associated conditions. Unfortunately, the use of antiretroviral therapy for patients coinfected with HIV and Mycobacterium tuberculosis is still to be fully evaluated. The complexity of side-effects due to antituberculosis medication and drug interaction represent important issues and combining an effective anti-HIV treatment with antituberculosis therapy is still a clinical challenge. We discuss here a case of spleen tuberculosis in a human immunodeficiency virus-positive patient who had a successful response after a diagnostic splenectomy and medical treatment that included classical antituberculosis treatment associated with antiretroviral therapy without protease inhibitors.

Involvement of hormonal circadian secretion in the growth of HIV-infected children

OBJECTIVE

To evaluate the circadian secretion of hormones involved in the regulation of growth in childhood, namely growth hormone, insulin-like growth factor (IGF)-I, cortisol, adrenocorticotropin hormone (ACTH), and thyroid-stimulating hormone (TSH) in HIV-infected children.

DESIGN

The circadian secretory pattern of growth hormone, IGF-I, cortisol, ACTH and TSH was evaluated in 14 HIV-infected children; 13 healthy age- and sex-matched children were chosen as controls.

METHODS

Sampling was performed every 4 h from 0400 h to 2000 h and every 2 h from 2000 h to 0400 h. Rhythmometric data were analysed by single and population mean cosinor methods and by analysis of variance.

RESULTS

A statistically significant circadian rhythm for growth hormone, IGF-I and cortisol was detectable in HIV-seropositive children, but the mean basal IGF-I levels were below the normal range for age in 12 patients. A statistically significant circadian rhythm was not detectable for ACTH or TSH.

CONCLUSION

These results show that there is a loss of the physiological regulation of growth hormone-IGF-I axis and a modification of 24 h TSH profile in our HIV-infected children. These abnormalities might be involved in the altered growth mechanism leading to the failure to thrive that is a peculiar feature of HIV-infected children.

Combination of a drug targeting the cell with a drug targeting the virus controls human immunodeficiency virus type 1 resistance

Combinations of drugs targeting viral proteins have been used to limit or control drug resistance, which is the most important cause of treatment failure in HIV-1-infected individuals. We suggest an alternative approach, namely to target cellular proteins, which are less prone to mutations than viral proteins. Here we show that simultaneous inhibition of a cellular protein (by hydroxyurea) and a viral protein (by ddI) produces a consistent and sustained suppression of HIV-1 for as long as 40 weeks in the absence of virus rebound. We identified the mechanism to explain this lack of rebound: although the combination of the two drugs did not prevent the emergence of mutant viral strains resistant to didanosine (ddI) in these patients, the mutants were still sensitive to standard doses of ddI in the presence of hydroxyurea. These in vivo results were consistent with our in vitro observations: HIV-1 molecular clones resistant to ddI were rendered sensitive to this drug (at concentrations routinely achievable in vivo) after addition of hydroxyurea. This phenomenon can be explained by the observation that hydroxyurea decreases the level of dATP, the cellular competitor of ddI. A low level of dATP favors the incorporation of ddI, even if the viral reverse transcriptase is resistant to this nucleoside analog. This is a novel mechanism of control of resistance and it explains the efficacy of a treatment that is well tolerated, simple, and inexpensive.

Circadian secretory pattern of growth hormone, insulin-like growth factor type I, cortisol, adrenocorticotropic hormone, thyroid-stimulating hormone, and prolactin during HIV infection

The circadian rhythms of plasma growth hormone (GH), insulin-like growth factor type I (IGF-I), cortisol, adrenocorticotropic hormone (ACTH), thyroid-stimulating hormone (TSH), and prolactin (PRL) were evaluated in 13 HIV-seropositive patients (8 males and 5 females; mean age [+/-SD], 30 +/- 5 years), classified as CDC C2. Sixteen clinically healthy subjects (9 males and 7 females; mean age [+/-SD], 32 +/- 8 years) were chosen as control group. Samples were taken every 4 hr from 04:00 to 20:00 and every 2 hr from 20:00 to 04:00. Plasma GH was evaluated by IRMA procedure, plasma IGF-I by RIA (after separation of soluble IGF-I from IGF-I-binding proteins, using acid-ethanol extraction), plasma cortisol by a solid-phase RIA, plasma ACTH by double-antibody RIA, and serum TSH and serum PRL by a solid-phase two-site fluoroimmunometric assay. Rhythmometric data were analyzed by single and population mean cosinor analysis; the comparison of the parameters of the rhythm between patients and controls was carried out by the mesor test and the amplitude-acrophase Hotelling test. Alterations of the circadian pattern of GH, IGF-I, cortisol, ACTH, TSH, and PRL were demonstrated in HIV-seropositive patients. In fact, the circadian profiles of these hormones were clearly flattened and no statistically significant 24-hr rhythm was detectable (with the exception of cortisol). These results are consistent with the hypothesis that alterations of the circadian temporal structure may already be present in HIV-seropositive patients without wasting and infectious complications.

Hydroxyurea and didanosine is a more potent combination than hydroxyurea and zidovudine

The in vitro and in vivo antiviral activity of hydroxyurea in combination with either zidovudine or didanosine was evaluated in primary human peripheral mononuclear cells and in a cohort of 29 asymptomatic patients infected with HIV. In vitro, hydroxyurea alone did not significantly affect HIV replication, whereas the combination of hydroxyurea with didanosine was more effective than the combination of hydroxyurea with zidovudine. Our clinical results confirmed these studies. Patients were randomly assigned to five arms (zidovudine, hydroxyurea or didanosine monotherapy, or hydroxyurea in combination with either zidovudine or didanosine) to evaluate preliminary safety and efficacy. Bone-marrow toxicity occurred in two patients treated with zidovudine plus hydroxyurea, alopecia was reported in one patient treated with hydroxyurea monotherapy, and there were no toxic effects recorded in the remaining three groups. Plasma viraemia was not influenced by hydroxyurea monotherapy, and the hydroxyurea-zidovudine combination did not give any advantage over either zidovudine or didanosine monotherapy (0.3-0.5 log decrease in plasma viraemia). In contrast, a 1.1 log drop in plasma viraemia was observed in patients treated with hydroxyurea plus didanosine, this reduction was sustained throughout the 24-week course of the treatment. Combination therapy with hydroxyurea and didanosine exhibited statistically significant improvements compared with the other therapeutic approaches. Although further clinical trials are required, these results suggest that hydroxyurea in combination with didanosine might be an effective and well-tolerated, simple and affordable, treatment for HIV infection.

Antigen-specific oligoclonal IgG in AIDS-related cytomegalovirus and toxoplasma encephalitis

We retrospectively studied serum and cerebrospinal fluid (CSF) specimens from AIDS patients with either Cytomegalovirus (2 cases) or Toxoplasma gondii (5 cases) encephalitis. The samples, which had previously proved to be negative for total IgG oligoclonal bands (OCBs), were investigated for antigen-specific OCBs directed to the disease-related opportunistic agent.

MATERIAL & METHODS

Paired serum and CSF samples from the given AIDS patients were considered. We undertook affinity immunoblotting of either virus- or protozoan-specific IgG onto antigen-coated nitrocellulose paper after protein separation by agarose isoelectric focusing (IEF).

RESULTS

Antigen-specific OCBs to the disease-related opportunistic agent were detected in serum and in CSF samples from all the patients.

CONCLUSIONS

During overt AIDS, routine IEF methods may fail to detect OCBs, probably because nonspecific polyclonal hypergammaglobulinemia, which is typical of this disease, reduces their visibility. Our IEF/immunoblotting profiles are characterized by identical serum and CSF bands. The detection of antigen-specific OCBs may support the diagnosis of some opportunistic infections of the central nervous system in AIDS.

Longitudinal neuropsychological evaluation of HIV-infected intravenous drug users

The present study aimed to describe the cognitive status of a group of HIV-positive asymptomatic intravenous drug users (IVDU) and changes which occurred over a 12-month follow-up period. Forty-two HIV positive IVDU were selected and matched for age, sex, educational level and pattern of drug abuse with 39 seronegative IVDU controls. Baseline and follow-up evaluation included neuropsychological tests exploring attention, language, memory, logic and visuomotor abilities, biological markers and clinical parameters. About one-third of both seropositive and seronegative subjects showed at baseline slight cognitive deficits, which did not change during the follow-up period.

Prognostic determinants of six-month morbidity and mortality in heart transplant recipients. The Italian Study Group on Infection in Heart Transplantation

BACKGROUND

Knowledge of time course and risk factors for morbidity and mortality may allow better cardiac graft allocation, surveillance timing, and planning of immunosuppressive strategies.

METHODS

Six-month morbidity and mortality were retrospectively analyzed in a multiinstitutional series of 645 heart transplant recipients.

RESULTS

During a 3432 patient-months follow-up, 87 patients died of infection (n = 11), rejection (n = 11), multiorgan failure (n = 9) and other transplant-related causes (n = 56); six-month survival rate was 86%. Three hundred thirty-seven recipients had 967 treated rejection episodes (2.87 episodes/patient with rejection, lethality 3.2%); 223 major infectious episodes occurred in 162 patients (1.38 episodes/infected patient, lethality 7%). Six-month rejection and infection-free survival rates were 44% and 73%. Total mortality and cause-specific morbidity sharply declined after the first month; 160 patients (25%) had no events during follow-up. At multivariable analysis, significant risk factors for mortality were postoperative acute kidney failure, prolonged cardiopulmonary bypass time, and previous cardiac surgery. Rejection was associated with steroid-free and globulin-free immunosuppression and infection was associated with steroid immunosuppression, cytolytic treatment, venous lines placement greater than 7 days, and mechanical ventilation time. No single or combination of variables was able to discriminate patients with an event-free course.

CONCLUSIONS

Morbidity and mortality have the highest incidence during the early posttransplantation phase. Preoperative variables are of limited value with respect to immunosuppressive treatment in predicting outcome. Infection is far less frequent than rejection but, in view of the higher lethality rate, deserves a vigorous effort for prevention, which is best addressed by appropriate modulation of immunosuppressive strategies.

[Clinical aspects of immunoneuroendocrine alterations in HIV infection]

A number of studies confirm that any human tissue can be targeted by HIV, and also the endocrine system is involved during HIV infection. No endocrine adenus is saved by the assault of the opportunistic pathogens that overrun the organism unprotected due to the severe and progressive immune deficits induced by the HIV. As a consequence clinical, but often subclinical alterations can be detected that underline the close relationship among the systems of body adaptation to the environment (immune, endocrine, and nervous). Indeed these alterations can be viewed as an immunoneuroendocrine pathology. AIDS is a paradigmatic syndrome for the variety of immune dysfunctions, and also presents endocrine and neurological dysfunctions, which allow to better understand the connections among these systems, and the interactions of HIV with the immunoneuroendocrine dynamics.

Clinical and virological monitoring of human cytomegalovirus infection in 294 heart transplant recipients

Two hundred and ninety-four heart transplant recipients (HTR) were followed prospectively for a mean of 44.9 +/- 28.4 (range 1.0-100.8 months) after transplantation (tx). Immunosuppression was based on cyclosporine, azathioprine, and steroids, supplemented by a 7-day course of antithymocyte globulins. All patients were virologically monitored by inoculating aliquots of 2 x 10(5) peripheral blood polymorphonuclear leukocytes (PMNs) onto human embryonic lung fibroblasts monolayers grown in shell vials for early cytomegalovirus (CMV) identification and quantification (viremia). The same number of PMNs was cytocentrifuged onto glass slides for direct CMV pp65 antigen detection and quantification (antigenemia). Heparinized blood samples were collected weekly during the first 3 months following tx and at least twice a week if antigenemia and viremia levels were increasing. After 3 months, samples were collected if antigenemia and viremia persisted or when clinically indicated. The overall incidence of CMV infection was 53.4% (157/294). Only 32.4% (51/157) of the viremic patients required antiviral treatment because of symptomatic infection. Of the remaining 106 untreated CMV viremic HTR, 104 were asymptomatic while 2 had only mild clinical symptoms. The overall incidence of CMV infection in pre-tx CMV seropositive (CMV+) HTR was 50.9% (136/267); 75.7% (103/136) were asymptomatic and 24.3% (33/267); 75.7% (103/136) were asymptomatic and 24.3% (33/136) were symptomatic. The overall incidence of CMV infection in pre-tx CMV-seronegative (CMV-) HTR was 77.8% (21/27; P = 0.007 vs. seropositive HTR). Among 22 CMV- HTR with CMV+ donor, 20 (90.9%) had a CMV infection and all of them were symptomatic (versus 1 of 5 (20%) CMV- HTR with CMV- donor; P = 0.002, Fisher's exact test). The median numbers of circulating CMV-infected PMNs detected at the onset of clinical symptoms by the antigenemia and viremia assays were 385/2 x 10(5) and 100/2 x 10(5), respectively.

Use of subcutaneous implantable infusion systems in neoplastic and AIDS patients requiring long-term venous access

OBJECTIVE

To evaluate the life span and complication rates of totally implantable infusion devices in patients with short bowel syndrome and in immunocompromised patients with AIDS, lymphoma, and myeloma who required long-term central venous access.

DESIGN

Prospective open study.

SETTING

University hospital, Italy.

SUBJECTS

Group I - 5 patients with short bowel syndrome; group II - 11 patients with AIDS; and group III - 15 patients with lymphoma or multiple myeloma (1 of whom had 2 devices implanted).

MAIN OUTCOME MEASURES

Duration of implantation and incidence of catheter-related complications.

RESULTS

The mean duration/patient of the catheter was 422 days (range 20-1257) in group I; 104 days (range 43-262) in group II; and 415 days (range 62-1280) in group III. There were no catheter related complications in the patients in group I (short bowel syndrome). Of the 11 patients with AIDS (group II) 4 developed catheter related infections (0.32/100 catheter days), and 1 developed a thrombotic occlusion. All 5 catheters were removed (3 for infection). Of the 15 patients with lymphoma or myeloma who had 16 catheters implanted (group III), 1 patient developed 3 infective episodes (0.05/100 catheter days), 1 catheter migrated and 1 occluded. All 3 catheters were removed.

CONCLUSION

Totally implantable infusion systems can safely be used for prolonged periods in immunocompromised patients, including those with AIDS if their life expectancy is reasonable.

Hepatitis C virus (HCV) core serotypes in chronic HCV infection

Recently, two distinct hepatitis C virus (HCV) serologic types have been identified on the basis of amino acid variations in the core region. The two serologic types can readily discriminate between genotypes I-II-V (serotype 1) and III-IV (serotype 2), according to the Okamoto classification. We compared HCV core serotyping with genotyping with sera from 363 anti-HCV-positive patients (309 HCV RNA positive by PCR) using a synthetic core peptide-based enzyme immunoassay and PCR amplification of core region sequences with type-specific primers, respectively. Serologic responses to HCV serotypes were successfully identified in 164 (45%) patients, of whom 153 were viremic. Eighty-nine patients had evidence of exposure to serotype 1: 8 of these were infected with genotype I, 50 were infected with genotype II, 2 were infected with genotype III, 7 were infected with genotype V, 13 had infections with mixed genotypes, 3 were infected with an indeterminate genotype, and 6 were nonviremic. Seventy-four patients had been exposed to serotype 2: 64 were infected with genotype III, 3 were infected with mixed genotypes, 2 were infected with an indeterminate genotype, and 5 were nonviremic. The serum of one patient, infected with genotype III, showed reactivity to both serotypes. Comparative evaluation of HCV core region serotyping and genotyping with sera from 294 viremic patients infected with a known HCV genotype showed a remarkable concordance between HCV core region genotyping and serotyping, with only 2 apparently discordant serum samples (both from patients with genotype III infection) of 148 (1.4%) successfully serotyped samples. Serotype 1 infection was more frequently observed in patients with overt chronic liver disease and accounted for all successfully serotyped samples from intravenous drug abusers. In contrast, serotype 2 was more prevalent in subjects with biochemically silent HCV infection (alanine aminotransferase, < 45 U/liter), in agreement with previous findings at the molecular level. HCV core serologic typing is a simple, inexpensive, and highly reproducible assay that can be applied to more than 50% of viremic HCV antibody carriers prior to the use of more sophisticated molecular typing techniques. Moreover, it may be helpful in tracking transmissions routes, particularly for incorrectly stored samples in which the RNA has degraded or for subjects who have cleared the virus and therefore have only antibodies remaining to testify to a remote infection. The lack of recognition of the core sequence from residues 67 to 81, which contains a minor B-cell epitope used to detect type-specific immunoreactivity, may explain the negative serologic findings for half of the patients.

[AIDS: biological aspects]

In June 1981 a new clinical syndrome, now called acquired immunodeficiency syndrome (AIDS) was first reported by the CDC. This entity has grown to be a pandemic disease with major socioeconomics, political and medical consequences. HIV-induced immunodeficiency infection typically occurs gradually over several years and leads to secondary opportunistic infections and malignancies. Similar features are observed in transplant recipients; the same clinical and diagnostic management is mandatory, but only in transplant complications an effective cure is possible.

[AIDS: organizational and medico-legal problems]

The medical imaging of AIDS patients may turn out a major challenge for hospital organization, since the specific problems related to this syndrome in terms of abnormal changes and increased diagnostic burden are to be matched with infection control procedures. Data obtained from 12 radiology departments in Lombardia hospitals where an Infectious Disease Department is present may yield valuable indications about the optimization of resources and how to implement sound cost-benefit measures while taking care of patient needs. Professional exposure to HIV may be substantially reduced by educational and practical measures, whereas strict hygienic standards applied to hospital environment and individual patients are of great value in controlling nosocomial infections in this population of immunodepressed individuals. The growing problem of HIV seropositive health care workers may be positively addressed with a modulated approach combining the contrasting issues of patients safety and non-discriminating job policy.

Sternal osteomyelitis due to Aspergillus fumigatus after cardiac surgery

Sternal osteomyelitis due to Aspergillus fumigatus after cardiac surgery occurred in two nonimmunosuppressed patients. The clinical features of the infection were markedly different in the two cases. In the first patient, sepsis showed a late and insidious onset followed by slow progression. In the second case, fungi were isolated from wound swabs within a few days of surgery and the clinical picture showed acute onset and rapid progression. Only a few cases of sternal osteomyelitis due to Aspergillus have been described previously after cardiac surgery. Aspergillus infection should be considered in the differential diagnosis of mediastinitis after cardiac surgery, especially in a clinical setting of otherwise unexplained sepsis or nonhealing wound despite apparently adequate treatment.