Discontinuation of secondary prophylaxis against Pneumocystis carinii pneumonia in patients with HIV infection who have a response to antiretroviral therapy. Eight European Study Groups

How effectively does HAART restore immune responses to Mycobacterium tuberculosis? Implications for tuberculosis control

Use of highly active antiretroviral treatment (HAART) has had a major impact on HIV-associated morbidity and mortality in industrialized countries. Access to HAART is now expanding in low-income countries where tuberculosis (TB) is the most important opportunistic disease. The incidence of TB has been fueled by the HIV epidemic and in many countries with high HIV prevalence current TB control measures are failing. HAART reduces the incidence of TB in treated cohorts by approximately 80% and therefore potentially has an important role in TB control in such countries. However, despite the huge beneficial effect of HAART, rates of TB among treated patients nevertheless remain persistently higher than among HIV-negative individuals. This observation raises the important question as to whether immune responses to Mycobacterium tuberculosis (MTB) are completely or only partially restored during HAART. Current data suggest that full restoration of circulating CD4 cell numbers occurs only among a minority of patients and that, even among these, phenotypic abnormalities and functional defects in lymphocyte subsets often persist. Suboptimal restoration of MTB-specific immune responses may greatly reduce the extent to which HAART is able to contribute to TB control at the community level because patients receiving HAART live much longer and yet would maintain a chronically heightened risk of TB.

The rate of serious bacterial infections among HIV-infected children with immune reconstitution who have discontinued opportunistic infection prophylaxis

OBJECTIVE

Receipt of highly active antiretroviral therapy is associated with a decrease in the incidence of opportunistic infections (OIs) among HIV-infected adults. The goal of Pediatric AIDS Clinical Trials Group protocol 1008 was to evaluate prospectively the incidence of serious bacterial infections (SBIs) and other OIs after discontinuation of OI and/or Pneumocystis jiroveci pneumonia (PCP) prophylaxis among HIV-infected pediatric subjects who experienced immune reconstitution while receiving stable antiretroviral therapy.

METHODS

HIV-infected children and adolescents, 2 to 21 years of age, who had received OI and/or PCP prophylaxis for > or =6 months were enrolled if they had sustained responses (>16 weeks before study entry) to antiretroviral therapy, with CD4+ cell percentages of > or =20% for patients >6 years of age or > or =25% for patients 2 to 6 years of age. Prophylaxis was discontinued at entry. To identify whether any correlation existed between functional immune reconstitution and protection from OIs, subjects were immunized with the hepatitis A virus vaccine. The association between the humoral immune response and the likelihood of developing an OI was evaluated.

RESULTS

A total of 235 HIV-infected subjects from 43 participating sites had a median follow-up period of 132 weeks, yielding 547 person-years of observation. Twenty SBIs were observed among 19 subjects, resulting in an incidence rate of 3.66 SBIs per 100 person-years (95% confidence interval: 2.24-5.66 SBIs per 100 person-years). Sixteen of the events were presumed bacterial pneumonia, with 4 proven SBIs. One participant experienced 2 separate pneumonia episodes, of presumed bacterial cause. Ten subjects who developed SBIs had baseline CD4+ cell counts of > or =750 cells per mm3, and 15 had CD4+ cell percentages of > or =25% at the time of their SBIs. Two subjects died as a result of non-SBI-related causes. There were no statistically significant differences in changes over time in CD4+ cell counts or CD4+ cell percentages between subjects who experienced primary end points and those who did not. There was no evidence that baseline protease inhibitor use, gender, race/ethnicity, age, or CD4+ cell count or percentage affected the time to development of a SBI.

CONCLUSIONS

OI or PCP prophylaxis can be withdrawn safely for HIV-infected pediatric patients who experience CD4+ cell recovery while receiving stable antiretroviral therapy. More studies are needed to assess the association between antibody responses to neoantigens and the development of SBIs.

Impact of highly active antiretroviral therapy on incidence and management of human immunodeficiency virus-related opportunistic infections

We review the changes in incidences of HIV-related opportunistic infections and the safety of discontinuation of primary and secondary prophylaxis for HIV-related opportunistic infections in patients achieving immune restoration after the introduction of highly active antiretroviral therapy (HAART). HIV-related opportunistic infections continue to occur in patients who are newly diagnosed with HIV infection, those in the early course of HAART or non-adherent to HIV care and HAART, and those in whom non-HIV-related infections have emerged as a significant cause of morbidity and mortality in the post-HAART era. Clinical studies of patients with tuberculosis and HIV co-infection are reviewed to provide appropriate regimen combinations of rifamycins and antiretrovirals, which have varying degrees of drug-drug interactions that have posed challenges in the management of tuberculosis as well as HIV infection.

Long-term safety of discontinuation of secondary prophylaxis against Pneumocystis pneumonia: prospective multicentre study

OBJECTIVES

To assess the long-term safety of discontinuation of secondary anti-Pneumocystis prophylaxis in HIV-infected adults treated with antiretroviral combination therapy and who have a sustained increase in CD4 cell counts.

DESIGN

Prospective observational multicentre study.

PATIENTS AND METHODS

The incidence of P. jirovecii pneumonia after discontinuation of secondary prophylaxis was studied in 78 HIV-infected patients on antiretroviral combination therapy after they experienced a sustained increase in CD4 cell counts to at least 200 x 10(6) cells/l and 14% of total lymphocytes measured twice at least 12 weeks apart.

RESULTS

Secondary prophylaxis was discontinued at a median CD4 cell count of 380 x 10(6) cells/l. The median follow-up period after discontinuation of secondary prophylaxis was 40.2 months, yielding a total of 235 person-years of follow-up. No cases of recurrent P. jirovecii pneumonia occurred during this period. The incidence was thus 0 per 100 person-years with a 95% upper of confidence limit of 1.3 cases per 100 patient-years.

CONCLUSIONS

Discontinuation of secondary prophylaxis against P. jirovecii pneumonia is safe even in the long term in patients who have a sustained immunologic response on antiretroviral combination therapy.

A prospective multicentre study of discontinuing prophylaxis for opportunistic infections after effective antiretroviral therapy

OBJECTIVE

To assess the medium-term safety of discontinuing prophylaxis (primary or secondary) for opportunistic infections following an effective response to antiretroviral therapy.

METHODS

Participating clinical sites prospectively identified patients in whom the discontinuation of prophylaxis for any opportunistic infection was considered to be clinically indicated, although CD4 levels were not predefined. A follow-up report was subsequently sent every 6 months requesting information on changes in prophylaxis, antiretroviral drugs, new AIDS-defining events, and CD4 cell count results.

RESULTS

Prophylaxis for Pneumocystis carinii pneumonia (PCP) was withdrawn in 524 patients (426 primary and 98 secondary prophylaxis), prophylaxis for Mycobacterium avium complex (MAC) was withdrawn in 28 patients (13 primary and 15 secondary), and prophylaxis for cytomegalovirus (CMV) retinitis was withdrawn in 10 patients. CD4 counts were generally maintained above accepted prophylaxis threshold levels during the period of follow up (95-98% of the time). Total follow up to last report or re-continuation of prophylaxis was 680 and 144 person-years for patients discontinuing primary and secondary PCP prophylaxis, respectively. No cases of PCP were reported, giving incidence rates of 0.0 (upper 95% confidence limit 0.4) and 0.0 (2.1) per 100 person-years. No cases of MAC were reported, but one patient had a recurrence of CMV retinitis. PCP prophylaxis was restarted in 30 patients; no patients restarted MAC or CMV prophylaxis.

CONCLUSIONS

Previous studies have demonstrated a low risk of PCP in the short term following the withdrawal of prophylaxis in patients who have responded well to antiretroviral therapy. The present study suggests a continuing low level of risk with extended follow up, provided adequate CD4 count levels are maintained. The case of recurrent CMV retinitis in a patient with impressive immunological and virological response indicates the need for close monitoring of patients previously diagnosed with this condition.

Differential CD4 T-cell response in HIV-1-infected patients using protease inhibitor-based or nevirapine-based highly active antiretroviral therapy

OBJECTIVES

To study the dynamics of CD4 T-lymphocyte counts (CD4 counts) after the initiation of either protease inhibitor (PI)-based or nevirapine (NVP)-based first-line highly active antiretroviral therapy (HAART).

DESIGN AND METHODS

A retrospective cohort study of 1029 HIV-infected antiretroviral therapy-naive patients initiating either PI-based or NVP-based HAART was carried out. Patients were censored as soon as they experienced virological failure, or changed their original antiretroviral regimen for any reason.

RESULTS

In total, 920 and 109 patients initiated PI- and NVP-based HAART, respectively. The patients in the PI group more often had AIDS (15 vs. 6% in the NVP group), had a lower median baseline CD4 count (234 vs. 250 cells/microL in the NVP group) and had higher median baseline plasma HIV-1 RNA levels (pVL) (5.0 vs. 4.7 log10 HIV-1 RNA copies/mL in the NVP group). After 96 weeks of follow-up, the mean increase from baseline in CD4 count, adjusted for baseline CD4 count, age, gender and baseline pVL, was 310 cells/microL in the PI group and 212 cells/microL in the NVP group (P=0.003). This difference was mainly attributable to the patients in the NVP group initiating HAART with a baseline CD4 count below 200 cells/microL. There were no differences between the PI and NVP groups with respect to the change in the number of CD4 cells as a proportion of the total number of lymphocytes.

CONCLUSION

Patients successfully treated with NVP-based HAART have a smaller increase in absolute CD4 cells compared with those treated with PI-based HAART.

Traitement et prévention des infections opportunistes au cours de l'infection par le VIH : mise au point en 2004. Partie 1 : pneumocystose et protozooses

Remarkable progress has been made in antiretroviral therapeutics, as well as in the prophylaxis and treatment of opportunistic infections, since the beginning of the AIDS epidemic. The patient's life expectancy and quality of life have consequently improved, thanks to better management of opportunistic diseases. The introduction of protease inhibitors-containing regimen (i.e. Highly Active Antiretroviral Therapy or HAART), since 1996, has drastically reduced the incidence of opportunistic infections by restoring immunity. The large panel of antiretroviral drugs responsible for frequent sustained viral and immune responses has thus allowed a new definition of guidelines for the prophylaxis and treatment of opportunistic infections. A better use of prophylactic drugs should help reduce the risk of drug-related toxicity and pharmaceutical interactions. It should also decrease the cost of HIV management and eventually increase compliance to treatment and quality of life.

HIV Cohort Collaborations: Proposal for Harmonization of Data Exchange

HIV cohort studies have provided useful information on the natural history of HIV infection and the effects of antiretroviral therapy. It has become increasingly common to combine data from several cohorts into one dataset in order to address certain specific questions with more statistical power than can be achieved with the individual studies. This requires each cohort to map data into a standard format before merging. Until recently, this standard format has differed for each such collaborative analysis. We have therefore developed the HIV Cohort Data Exchange Protocol (HICDEP), which is freely available at http://www.cphiv.dk/HICDEP.pdf . Once individual cohorts have set up a means of transfering data into this format, as and when required, this should greatly facilitate data merging for future joint analyses. The HICDEP incorporates data from HIV drug resistance tests, which have been particularly challenging for cohorts to integrate into databases.

Immune reconstitution in HIV-infected patients

The prognosis of patients infected with human immunodeficiency virus (HIV) type 1 has dramatically improved since the advent of potent antiretroviral therapies (ARTs), which have enabled sustained suppression of HIV replication and recovery of CD4 T cell counts. Knowledge of the function of CD4 T cells in immune reconstitution was derived from large clinical studies demonstrating that primary and secondary prophylaxis against infectious agents, such as Pneumocystis jirovecii (Pneumocystis carinii), Mycobacterium avium complex, cytomegalovirus, and other pathogens, can be discontinued safely once CD4 T cell counts have increased beyond pathogen-specific threshold levels (usually >200 CD4 T cells/mm3) for 3-6 months. The downside of immune reconstitution is an inflammatory syndrome occurring days to months after the start of ART, with outcomes ranging from minimal morbidity to fatal progression. This syndrome can be elicited by infectious and noninfectious antigens. Microbiologically, the possible pathogenic pathways involve recognition of antigens associated with ongoing infection or recognition of persisting antigens associated with past (nonreplicating) infection. Specific antimicrobial therapy, nonsteroidal anti-inflammatory drugs, and/or steroids for managing immune reconstitution syndrome should be considered.

Prevention of opportunistic infections in adult and adolescent patients with HIV infection. GESIDA/National AIDS Plan guidelines, 2004 [correction]

OBJECTIVE

To provide an update of guidelines from the Spanish AIDS Study Group (GESIDA) and the National AIDS Plan (PNS) committee on the prevention of opportunistic infections in adult and adolescent HIV-infected patients.

METHODS

These consensus recommendations have been produced by a group of experts from GESIDA and/or the PNS after reviewing the earlier document and the scientific advances in this field in the last years. The system used by the Infectious Diseases Society of America and the United States Public Health Service has been used to classify the strength and quality of the data.

RESULTS

This document provides a detailed review of the measures for the prevention of infections caused by viruses, bacteria, fungi and parasites in the context of HIV infection. Recommendations are given for preventing exposure and for primary and secondary prophylaxis for each group of pathogens. In addition, criteria are established for the withdrawal of prophylaxis in patients who respond well to highly active antiretroviral therapy (HAART).

CONCLUSIONS

HAART is the best strategy for the prevention of opportunistic infections in HIV-positive patients. Nevertheless, prophylaxis is still necessary in countries with limited economic resources, in highly immunodepressed patients until HAART achieves beneficial effects, in patients who refuse to take or who cannot take HAART, in those in whom HAART is not effective, and in the small group of infected patients with inadequate recovery of CD4+ T lymphocyte counts despite good inhibition of HIV replication.

Discontinuation of maintenance therapy for cryptococcal meningitis in patients with AIDS treated with highly active antiretroviral therapy: an international observational study

We conducted a retrospective, multicenter study evaluating the safety of discontinuing maintenance therapy for cryptococcal meningitis after immune reconstitution. Inclusion criteria were a previous definitive diagnosis of cryptococcal meningitis, a CD4 cell count of >100 cells/microL while receiving highly active antiretroviral therapy (HAART), and the subsequent discontinuation of maintenance therapy for cryptococcal meningitis. The primary end point was relapse of cryptococcal disease. As of July 2002, 100 patients were enrolled. When maintenance therapy was discontinued, the median CD4 cell count was 259 cells/microL and the median plasma virus load was <2.30 log10 copies/mL, and serum cryptococcal antigen was undetectable in 56 patients. During a median follow-up period of 28.4 months (range, 6.7-64.5; 262 person-years), 4 events were observed (incidence, 1.53 events per 100 person-years; 95% confidence interval, 0.42-3.92). Three of these patients had a CD4 cell count of >100 cells/microL and a positive serum cryptococcal antigen test result during the recurrent episode. In conclusion, discontinuation of maintenance therapy for cryptococcal meningitis is safe if the CD4 cell count increases to >100 cells/microL while receiving HAART. Recurrent cryptococcal infection should be suspected in patients whose serum cryptococcal antigen test results revert back to positive after discontinuation of maintenance therapy.

Pneumocystis jiroveci Pneumonia in Adult Patients with AIDS

Pneumocystis jiroveci (P. carinii) is an opportunistic pathogen that has gained particular prominence since the onset of the AIDS epidemic. Among several important advances in diagnosis and management, appropriately targeting chemoprophylaxis to HIV-infected patients at high clinical risk for P. jiroveci pneumonia and the introduction of effective combination anti-retroviral therapy (including highly active antiretroviral therapy [HAART]) have contributed to the reduced incidence of P. jiroveci pneumonia. Despite the success of these clinical interventions, P. jiroveci pneumonia remains the most common opportunistic pneumonia and the most common life-threatening infectious complication in HIV-infected patients. Trimethoprim/sulfamethoxazole (cotrimoxazole) remains the first-line agent for effective therapy and chemoprophylaxis, and corticosteroids represent an important adjunctive agent in the treatment of moderate-to-severe P. jiroveci pneumonia. However, problems of chemoprophylaxis and treatment failures, high rates of adverse drug reactions and drug intolerance to first-line antimicrobials, high rates of relapse or recurrence with second-line agents, and newer concerns about the development of P. jiroveci drug resistance represent formidable challenges to the management and treatment of AIDS-related P. jiroveci pneumonia. With the expanding global problem of HIV infection, the intolerance or unavailability of HAART to many individuals and limited access to healthcare for HIV-infected patients, P. jiroveci pneumonia will remain a major worldwide problem in the HIV-infected population. New drugs under development as anti-Pneumocystis agents such as echinocandins and pneumocandins, which inhibit beta-glucan synthesis, or sordarins, which inhibit fungal protein synthesis, show promise as effective agents. Continued basic research into the biology and genetics of P. jiroveci and host defense response to P. jiroveci will allow the development of newer antimicrobials and immunomodulatory therapeutic agents to more effectively treat life-threatening pneumonia caused by this organism.

Early versus delayed antiretroviral therapy in patients with HIV infection : a review of the current guidelines from an immunological perspective

The development and implementation of highly active antiretroviral therapy (HAART) for the treatment of the human immunodeficiency virus has revolutionised the care of patients with this disease. Despite the positive impact that antiretroviral therapy has had on the lives of individuals with HIV infection, the adverse effects, potential long-term toxicities, complexity of regimens, development of drug resistance and cost have made decisions about when to initiate HAART difficult. The benefits and risks of antiretroviral therapy vary considerably among patients at different stages of disease, mainly as a result of the irreversible destruction of the immune system that occurs as HIV infection progresses. In acute HIV infection, the primary aim of treatment is preservation and reconstitution of HIV-specific immune function. In symptomatic or late-stage disease, the goal is control of viral replication with resulting improvement in non-HIV-specific immunity, which leads to decreased morbidity and increased survival. The most controversial decision involves when to start therapy in persons with asymptomatic chronic HIV, where the benefits are less well established and may be outweighed by the drawbacks, depending on the individual patient. In all patients, the advantages and disadvantages must be considered carefully, and the readiness and ability of the individual to adhere to a complex multidrug regimen needs to be assessed before the initiation of therapy.

Recurrence of Pneumocystis carinii pneumonia in an HIV-infected patient: apparent selective immune reconstitution after initiation of antiretroviral therapy

Although several studies have reported that it is safe to discontinue secondary Pneumocystis carinii pneumonia (PCP) prophylaxis in patients infected with HIV who experience a sustained immune response as a result of antiretroviral therapy, we describe a patient who developed recurrent PCP <3 months after discontinuing trimethoprim-sulfamethoxazole prophylaxis. He developed disease despite a sustained CD4 T-cell count above 200 cells/microL for more than 3 years while on antiretroviral therapy, as well as an apparent immune reconstitution against disseminated Mycobacterium avium complex (MAC) and Histoplasma capsulatum, for which he also discontinued therapy but without adverse effects. Thus, although increasing evidence continues to indicate that HIV-infected patients receiving combinations of antiretroviral therapies may regain specific immunity against opportunistic infections, our patient's experience suggests that this immune recovery may be selective and incomplete.

Epidemiological aspects of major opportunistic infections of the respiratory tract in persons with AIDS: Europe, 1993-2000

OBJECTIVE(S)

To describe the epidemiology of Pneumocystis carinii pneumonia (PCP), pulmonary tuberculosis (PTB) and recurrent bacterial pneumonia (RBP) as AIDS-defining illnesses (ADI) in Europe.

DESIGN

Analysis of AIDS surveillance data collected in the World Health Organization European region by EuroHIV, Saint Maurice, France.

METHODS

Adult AIDS cases notified between 1993 and 2000 were studied. Since AIDS diagnosis may be constituted by up to four concurrent illnesses, polytomous logistic regression odds ratios (OR) and 95% confidence intervals (CI) were computed. Time trends and correlates of PCP, PTB or RBP were assessed.

RESULTS

There were 181 296 ADI among the 142 447 AIDS cases included in this study. PCP was the commonest ADI in western Europe (17.8%) and PTB (20.4%) was the commonest ADI in eastern Europe. Within western Europe, PTB was more common in the south than in the north (OR, 1.5) and increased steadily over time. RBP increased until 1998 (from 1.9% to 3.7%) and thereafter declined. Young age was associated with an excess risk for PTB and, in comparison with heterosexuals, homosexual men were at higher risk for PCP (OR, 1.3). Injecting drug users (IDU) (OR, 2.8; 95% CI, 2.6-3.1) and recipients of blood (OR, 1.7; 95% CI, 1.4-2.2) were at increased risk for RBP.

CONCLUSIONS

This analysis highlighted the continuing importance of PCP and the increasing importance of PTB as an ADI in western Europe, and it emphasized the need to investigate more thoroughly the vast epidemic of AIDS-associated PTB in eastern Europe. IDU and recipients of blood should be considered as target groups for vaccination against RBP.

When to Start Antiretroviral Therapy and What to Start With-- A European Perspective

Although antiretroviral combination therapy has greatly improved the life expectancy of HIV-infected individuals, its use is hampered by considerable toxicity, the need for life-long near-perfect adherence to strict dosing regimens in order to avoid the emergence of drug resistance, and high cost. In this paper we review current understanding of when to best initiate antiretroviral therapy and what regimen to start with. The limitations of antiretroviral combination therapy are increasingly clear, and this has led to the current tendency to delay the initiation of therapy until CD4 cell counts have consistently dropped toward the 200 cells/mm(3 )mark, or until plasma HIV-1 RNA has increased to above 100,000 copies/mL. The need for optimal adherence also implies a "readiness" on the part of the patient to start treatment. Once the decision to commence therapy has been reached, what particular combinations of drugs to start with increasingly demands an individualized approach.

Pneumocystis carinii pneumonia in HIV negative patients with primary brain tumors

BACKGROUND

Pneumnocystis carinii pneumonia (PCP) is an opportunistic infection with rather adverse outcomes. An unexpected increase in cases of PCP was noted in the brain tumor population at the Johns Hopkins Hospital (JHH) in 2000. This prompted the present review of the clinical features and risk factors for PCP in the human immunodeficiency virus (HIV) negative brain tumor population.

METHODS

The study was located at the JHH. A retrospective review of medical records was done to identify patients with discharge diagnosis of PCP from 1980 to 2001. Patients who were HIV positive were excluded. A detailed analysis was done of patients with brain tumors.

RESULTS

From 1980 to 2001, 468 cases of PCP were identified, diagnosed histologically or clinically, of which 110 were patients with an underlying malignancy. Of the 110 cases 15 were seen in the brain tumor population. Of these, 6 patients were seen in 2000 and one in early 2001. Three of these had primary central nervous system (CNS) lymphoma (PCNSL) on high dose methotrexate. Eight of the fifteen episodes (53.3%) were fatal despite institution of antibiotics and supportive therapy.

CONCLUSION

The incidence and mortality due to Pneumocystis carinii among the brain tumor population is increasing. While corticosteroids are known immunosupressants, prescribing patterns for these medications has not changed lately. However, high dose methotrexate is now being used in PCNSL and could be a complicating factor. Since effective prophylaxis exists, it should be considered in patients with brain tumors receiving high dose steroids, high dose methotrexate or with lymphopenia.

The European research effort for HIV/AIDS, malaria and tuberculosis

The global emergency caused by HIV/AIDS, malaria and tuberculosis requires for new approaches and actions to confront these three major poverty-related diseases. In response to this emergency, the European Commission provides a broad comprehensive approach in a wide range of policy areas, including trade, development and research. For research, the overall strategy is to develop new drugs, vaccines or other effective interventions by two main mechanisms: (i) support of research projects for the development of new promising candidates through pre-clinical and early human testing and (ii) establishment of a programme to support phases II and III clinical trials in Africa. The Sixth Framework Programme (FP6) (2002-2006) allocates a total of 400 million euro to research on HIV/AIDS, malaria and tuberculosis with about 200 million for each of the two interlinked components. Research projects, aiming at developing new promising candidates, should create large consortia capable of integrating different approaches and disciplines providing the necessary critical mass to test and compare different scientific ideas. Projects should cover different phases in the development process ranging from basic knowledge generated from genomics or immunology to pre-clinical testing in animal models and finally validation in safety trials. The new instruments, mainly Integrated Projects and Network of Excellence, are the preferred means to implement the proposed approach. The European and Developing Countries clinical trials partnership (EDCTP) will help to overcome the bottleneck of demonstrating a proof of principle for promising vaccine or drug candidates in testing them in early efficacy trials in endemic areas, particularly in sub-Saharan Africa.

Prognosis and clinical evaluation of infection caused by Rhodococcus equi in HIV-infected patients: a multicenter study of 67 cases

OBJECTIVE

To assess the clinical characteristics and the factors that influenced the prognosis of patients with HIV and infection caused by Rhodococcus equi.

DESIGN

Observational, multicenter study in 29 Spanish general hospitals.

SETTING

These hospitals comprised a total of 20,250 beds for acute patients and served a population of 9,716,880 inhabitants.

PATIENTS

All patients with HIV and diagnosed R equi infection until September 1998.

RESULTS

During the study period, 19,374 cases of AIDS were diagnosed. Sixty-seven patients were included (55 male patients; mean +/- SD age, 31.7 +/- 5.8 years). At the time of diagnosis of R equi infection, the mean CD4+ lymphocyte count was 35/ micro L (range, 1 to 183/ micro L) and the stage of HIV infection was A3 in 10.4% of patients, B3 in 31.3%, C3 in 56.7%, and unknown in 1.5%. R equi was most commonly isolated in sputum (52.2%), blood cultures (50.7%), and samples from bronchoscopy (31.3%). Chest radiographic findings were abnormal in 65 patients (97%). Infiltrates were observed in all of them, with cavitations in 45 patients. The most active antibiotics against the strains isolated were vancomycin, amikacin, rifampicin, imipenem, ciprofloxacin, and erythromycin. After a mean follow-up of 10.7 +/- 12.8 months, 23 patients (34.3%) died due to causes related to R equi infection and 6 other patients showed evidence of progression of the infection. The absence of highly active antiretroviral therapy (HAART) was independently associated with mortality related to R equi infection (relative risk, 53.4; 95% confidence interval, 1.7 to 1,699). Survival of patients treated with HAART was much higher than that of patients who did not receive this therapy.

CONCLUSIONS

Infection by R equi is an infrequent, opportunistic complication of HIV infection and occurs during advanced stages of immunodepression. In these patients, it leads to a severe illness that usually causes a bacteremic, cavitary pneumonia, although HAART can improve the prognosis.

Impact of highly active antiretroviral therapy on the occurrence of bacteraemia in HIV-infected patients and their epidemiologic characteristics

OBJECTIVE

1. to assess the impact of highly active antiretroviral therapy (HAART) on the occurrence of bacteraemia in HIV-infected patients and their clinical and microbiological characteristics. 2. to identify risk factors for bacteraemia in this setting.

METHODS

The files of all HIV-infected patients hospitalized for an episode of bacteraemia in a 28-bed infectious diseases unit between January 1995 and December 1998 were reviewed. Cases occurring during HAART were compared to cases occurring in patients not receiving HAART. Furthermore, in a case-control study, patients with bacteraemia occurring during HAART were compared with other patients receiving HAART.

RESULTS

There were 74 episodes of bacteraemia in patients not receiving HAART and 31 episodes in patients receiving HAART. The occurrence of bacteraemia fell from 10.5/100 hospitalizations in 1995 to 5.5/100 in 1998 (P = 0.02 trend test). The occurence of P. aeruginosa bacteraemia fell sharply (9/398 vs 1/273, P = 0.05). A significant fall in catheter-related infections was observed between 1995 and 1998 (5.5% vs 1.8%). The two-thirds/one-third distribution of hospital-acquired and community-acquired infections remained stable throughout the period study. In patients receiving HAART, the case-control study showed by multivariate analysis, that a CD4 cell count of less than 100/ micro L [OR = 7.3 (1.9-49.7)], and the use of exogenous devices [OR = 13.3 (2.5-71)] were significantly associated with the risk of bacteraemia.

CONCLUSION

The introduction of HAART has been associated with a significant fall in the occurrence of bacteraemia. However, patients with a low CD4 cell count remain at risk of bacteraemia with similar microbiological and epidemiological characteristics than in the pre-HAART era.

HIV therapy in 2003: consensus and controversy

HIV therapy has well-established and substantial clinical benefits. Awareness of these benefits has brought many infected persons into care. Many more infected persons would be treated were it not for the frequent side effects associated with antiretroviral drugs. All antiretroviral agents can cause both short-term and long-term toxicities. This is a particularly vexing problem as current data does not allow accurate predictions of treatment toxicities and, in many cases, side effects are only partially reversible. Moreover, therapy is frequently associated with the selection of drug-resistant viral isolates and incomplete viral suppression. This is commonly caused by inadequate medication adherence and leads to increasingly severe virologic failure. The present review will address both the striking advantages of HIV therapy as well as the ongoing challenges in its application.

Discontinuation of secondary prophylaxis for Pneumocystis carinii pneumonia in human immunodeficiency virus-infected patients: a randomized trial by the CIOP Study Group

This subgroup analysis assessing secondary prophylaxis for Pneumocystis carinii pneumonia (PCP) describes a multicenter, open-labeled, randomized, controlled trial evaluating the discontinuation of PCP prophylaxis. The main inclusion criterion was a history of PCP and an increase in the CD4 cell count to >200 cells/microL associated with receipt of highly active antiretroviral therapy for >or=3 months. The primary end point was the development of definitive or presumptive PCP. A total of 146 patients were enrolled (77 in the treatment discontinuation arm). After >2 years, 1 definitive and 1 presumptive case of PCP were observed, both of which occurred in patients who discontinued therapy. In most patients, secondary prophylaxis for PCP can be safely discontinued after potent antiretroviral therapy is initiated, but the threshold of >200 CD4 cells/microL may not be considered absolutely safe. Patients who present with symptoms after discontinuation of secondary prophylaxis should be evaluated for PCP despite high CD4 count and complete virus suppression.

Managing the care of patients infected with bloodborne diseases

BACKGROUND

The emergence of the bloodborne pathogens HIV, the cause of AIDS; hepatitis B virus, or HBV; and hepatitis C virus, or HCV, has been a milestone in the history of the dental profession. In the early 1980s, new cases of AIDS increased dramatically, and fear of acquiring this disease compelled clinicians to modify the delivery of medical and dental care to allay fears of transmission on the part of both patients and health care workers. Arguably, the AIDS pandemic has been the most significant factor in the evolution and delivery of modern medical and dental care in the last century.

OVERVIEW

To help ally fears and remove barriers to caring for the HIV population, the Centers for Disease Control and Prevention, or CDC, introduced the concept of universal precautions in 1983. This was followed by the Occupational Safety and Health Administration's Bloodborne Pathogens Standard in 1991. Specific to the dental profession was the development of the principles of infection control in dentistry recommended by the CDC (1993); the American Dental Association (1995) and the Organization for Safety & Asepsis Procedures (1997). While initially difficult for some clinicians to acknowledge, these recommendations now are universally accepted throughout the profession, and provision of oral health care to patients infected with bloodborne disease is becoming commonplace. Compliance with recommended infection control practices remains an important component of dental practice. But it must be accompanied by an understanding of infectious and bloodborne diseases and the medical/dental management of the care of infected dental patients.

CONCLUSIONS AND PRACTICE IMPLICATIONS

The emergence of the bloodborne pathogens and the increasing number of infected patients who seek oral health care compel clinicians to have a thorough knowledge about bloodborne diseases and the medical/dental management of the care of patients presenting with HIV, HBV or HCV infection.

Pneumocystis carinii pneumonia in patients with and without HIV infection

Advances in the prevention and treatment of Pneumocystis carinii pneumonia in HIV infected patients have led to a decrease in the incidence and improved outcomes. Pneumocystis carinii pneumonia continues to be problematic in non-HIV infected immunocompromised patients.

Reconstitution of immune responses to tuberculosis in patients with HIV infection who receive antiretroviral therapy

STUDY OBJECTIVE

s: To assess the restoration of immune responses to tuberculosis, as manifested by secretion of T-helper type 1 cytokines (interferon [IFN]-gamma, interleukin [IL]-12, and IL-2) and T-helper type 2 cytokines (IL-10), in HIV-positive patients who receive antiretroviral therapy (ART).

DESIGN

Prospective cohort study.

SETTING

University hospital.

PATIENTS

Ten HIV-positive patients, all naïve to ART and all about to start ART for clinical indications, and 11 healthy, HIV-negative control subjects.

INTERVENTIONS

Assessment of T-cell proliferation and cytokine production after administration of ART to patients with HIV infection.

MEASUREMENTS AND RESULTS

All patients had a negative tuberculin skin test result at baseline and were anergic. Highly active ART reduced the viral load to very low levels in all patients within a short time after starting therapy. Blood samples were drawn every 2 months after starting therapy, and continued for 1 year while the patients continued to receive ART. There were trends toward increased proliferation of peripheral blood mononuclear cells (PBMCs) in response to Mycobacterium tuberculosis-specific stimuli, but these were delayed until several months of ART had elapsed. Similar trends were noted in relation to the secretion of IFN-gamma. Neither PBMC proliferation nor IFN-gamma secretion reached levels seen in healthy control subjects. No consistent trends in IL-2, IL-10, or IL-12 production were noted.

CONCLUSION

ART restores immune responses to M tuberculosis, although this restoration is delayed and does not reach levels seen in healthy, HIV-negative control subjects. These results may explain in part the phenomenon of paradoxic reactions to antituberculosis therapy in patients with HIV infection. A larger study in which patients are followed up for a longer period of time will allow the magnitude and timing of this reconstitution to be more precisely defined.

Management of Opportunistic Infection Prophylaxis in the Highly Active Antiretroviral Therapy Era

Prophylaxis and maintenance therapy against opportunistic infections are a mainstay of management of HIV-infected patients and have led to a significant improvement in quality of life and survival. Antiretroviral combination therapy (ART) has markedly changed the natural course of HIV infection. Incidence of opportunistic infections (OIs) has declined and survival after an OI has improved. Achieving a CD4 count of 200 cells/L after 6 months of ART is a valuable marker for low risk of OI afterwards. Therefore, recommendations on prophylaxis and maintenance therapy need to be redefined. Criteria for discontinuation, such as a CD4 count rise above threshold values and time above threshold values as response to ART, should be evaluated for the most frequent OIs. Reliable data in favor of discontinuation of primary prophylaxis against Pneumocystis carinii pneumonia, toxoplasmic encephalitis, and Mycobacterium avium infection have been published. Discontinuation of maintenance therapy against P. carinii pneumonia is possible, and may be safe against cytomegalovirus retinitis, M. avium, and cryptococcosis and toxoplasmosis in selected patients. Pharmacologic interactions between drugs used for OI prophylaxis and antiretroviral drugs need to be taken into account.

HIV-related morbidity and mortality in patients starting protease inhibitors in very advanced HIV disease (CD4 count of < 50 cells/microL): an analysis of 338 clinical events from a randomized clinical trial

BACKGROUND

AIDS defining events occur infrequently in the presence of CD4 counts above 200 cells/microL. It is, however, uncertain for most of the AIDS defining conditions whether this threshold can be considered equally safe in patients with a previously very low CD4 nadir.

METHODS

We evaluated in detail all the AIDS defining events observed during a 48-week clinical trial in 1251 nucleoside reverse transcriptase inhibitor-experienced patients who started protease inhibitors (PIs) at CD4 counts below 50 cells/microL. The type of event, immunological status at the moment of event and time between start of PI treatment and event occurrence were analysed cumulatively and by event type; event rates were calculated.

RESULTS

Concomitant data on CD4 counts were available for 338 AIDS defining events (81% of total events). Median time between start of treatment with PI and event was 94.5 days and median absolute CD4 value at the occurrence of event was 20 per microL. Only 14 events (in 12 patients) were observed above the threshold of 200 CD4 cells/microL. An analysis of the 67 deaths with concomitantly available CD4 counts (57%) showed a median CD4 count of 10 cells/microL, with only four deaths occurring in the presence of a CD4 count above 100 cells/microL.

CONCLUSIONS

Very few clinical AIDS defining conditions were observed in patients who start PIs at very low CD4 counts and with treatment restore absolute values in CD4 counts above 200 cells/microL. This threshold can therefore be considered a clinically effective goal of treatment with respect to occurrence of all AIDS defining conditions in patients starting PIs in very advanced HIV disease.

The evaluation of subcutaneous proleukin (interleukin-2) in a randomized international trial: rationale, design, and methods of ESPRIT

The Evaluation of Subcutaneous Proleukin in a Randomized International Trial (ESPRIT) is a large ongoing randomized trial of subcutaneous interleukin-2 (IL-2) plus antiretroviral therapy versus antiretroviral therapy alone in patients with HIV (human immunodeficiency virus) disease and CD4 cell counts of at least 300 cells/mm(3). The primary objective is to determine whether the addition of IL-2 to combination antiretroviral therapy improves morbidity and mortality. The aim is to recruit 4000 participants and follow them for an average of 5 years. Eligible subjects will be recruited at 275 investigational sites in 23 countries around the world. Coupled with broad eligibility criteria this will ensure widely applicable results. A range of secondary objectives will also be addressed in this setting that will include the conduct of observational studies and nested substudies with a public health focus. This article describes the rationale supporting the trial in addition to reviewing the study design, coordination, and governance.

Discontinuation of secondary prophylaxis against disseminated Mycobacterium avium complex infection and toxoplasmic encephalitis

We retrospectively studied outcomes for patients infected with human immunodeficiency virus who received highly active antiretroviral therapy (HAART) and had stopped receiving secondary prophylaxis against toxoplasmic encephalitis (TE) or disseminated Mycobacterium avium complex (MAC) infection. Nineteen patients had a history of TE, and 26 had a history of disseminated MAC infection. The median duration of secondary prophylaxis was 27 months, and the median duration of HAART before discontinuation of secondary prophylaxis was 22 months. Median CD4(+) cell counts at the time of cessation of secondary prophylaxis against TE or disseminated MAC infection were 404 and 105 cells/mm(3), respectively. Plasma virus load was undetectable in 68% of the patients who had a history of TE and in 31% of patients who had a history of disseminated MAC infection. Patients were followed up for a median of 29 months after discontinuation of secondary prophylaxis; no relapses occurred in patients with a history of TE, and 3 relapses occurred in patients with a history of disseminated MAC infection (incidence, 4 relapses per 100 person-years).

A controlled trial of itraconazole as primary prophylaxis for systemic fungal infections in patients with advanced human immunodeficiency virus infection in Thailand

Cryptococcal meningitis and Penicillium marneffei infection are common serious fungal infections in patients infected with human immunodeficiency virus (HIV) in Southeast Asia. In a prospective, double-blind trial, 63 patients with HIV infection and CD4+ lymphocyte counts of <200 cells/microL were randomized to receive oral itraconazole (200 mg per day), and 66 similar patients received a matched placebo. Both groups were monitored for evidence of invasive fungal infections. Baseline characteristics and the CD4+ cell counts of the 2 groups were similar. In the intent-to-treat analysis, a systemic fungal infection developed in 1 patient (1.6%) assigned to receive itraconazole (P. marneffei) and in 11 patients (16.7%) given placebo (7 patients had cryptococcal meningitis, and 4 patients had P. marneffei infection; P=.003, by the log-rank test). The incidence of recurrent or refractory mucosal candidiasis was significantly reduced in the itraconazole group. The 2 groups did not differ with regard to adverse effects. Primary prophylaxis with oral itraconazole is well tolerated and prevents cryptococcosis and penicilliosis marneffei in patients with advanced HIV infection, especially those with CD4+ lymphocyte counts of <100 cells/microL. However, prophylaxis with itraconazole was not found to be associated with a survival advantage when it was given to patients with advanced HIV disease.

Pulmonary manifestations of HIV infection in the era of highly active antiretroviral therapy

STUDY OBJECTIVES

To determine whether the spectrum of HIV-related pulmonary disease seen by a university medical center Pulmonary and Critical Care Medicine Service has changed since the introduction of highly active antiretroviral therapy (HAART).

DESIGN

Retrospective chart review.

SETTING

A tertiary care university hospital.

PATIENTS

All HIV-infected patients referred to the Pulmonary and Critical Care Medicine Service from January 1, 1993, through December 31, 1995 (era 1) and from July 1, 1997, through June 30, 2000 (era 2).

INTERVENTIONS

Inpatient and outpatient charts were reviewed for data regarding patient demographics, CD4 cell counts, viral load levels, duration of HIV seropositivity, history of opportunistic infections, and final diagnosis.

RESULTS

Pneumocystis carinii pneumonia (PCP) was less common in the HAART era than in the pre-HAART era, whereas bacterial pneumonia and non-Hodgkin's lymphoma (NHL) were more common in the HAART era than in the pre-HAART era. HAART was protective against PCP (odds ratio [OR], 0.37; confidence interval [CI], 0.16 to 0.89) in a manner dependent on the CD4 cell count. Patients receiving HAART were at increased risk for the development of bacterial pneumonia (OR, 2.41; CI, 1.12 to 5.17) and NHL (OR, 15.11; CI, 3.14 to 28.32). A history of PCP indicated a risk factor for bacterial pneumonia (OR, 2.14; CI, 1.13 to 4.04). A history of cytomegalovirus infection indicated a risk factor for NHL (OR, 6.0; CI, 1.27 to 28.32).

CONCLUSIONS

There have been significant changes in the spectrum of HIV-related pulmonary complications seen by our Pulmonary and Critical Care Medicine Service in the HAART era.

Discontinuation of Pneumocystis carinii prophylaxis in patients infected with human immunodeficiency virus: a meta-analysis and decision analysis

We performed a meta-analysis and a decision analysis on the discontinuation of prophylaxis for Pneumocystis carinii pneumonia (PCP) in patients infected with human immunodeficiency virus who had adequate immune recovery while receiving highly active antiretroviral therapy. In the meta-analysis (14 studies with 3584 subjects who had discontinued prophylaxis), 8 cases of PCP occurred during 3449 person-years (0.23 cases per 100 person-years [95% confidence interval, 0.10-0.46]). In the decision analysis, mortality and time spent alive without immunodeficiency in the modeled discontinuation strategy were similar to those in the continuation strategy. For patients who received primary prophylaxis, the discontinuation strategy led to slightly fewer episodes of PCP and fewer toxicity-related prophylaxis withdrawals (e.g., 8.6 vs. 34.5 cases per 100 patients during a 10-year period). Patients on the discontinuation strategy were more likely to be receiving trimethoprim-sulfamethoxazole when they became immunodeficient. Comparative results were similar for patients with prior PCP. Discontinuation of PCP prophylaxis in patients with adequate immune recovery is a useful strategy that should be widely considered.

Prevention of infection caused by Pneumocystis carinii in transplant recipients

Pneumocystis carinii remains an important pathogen in patients who undergo solid-organ and hematopoietic transplantation. Infection results from reactivation of latent infection and via de novo acquisition of infection from environmental sources. The risk of infection depends on the intensity and duration of immunosuppression and underlying immune deficits. The risk is greatest after lung transplants, in individuals with invasive cytomegalovirus disease, during intensive immunosuppression for allograft rejection, and during periods of neutropenia. Prophylaxis with trimethoprim-sulfamethoxazole (TMP-SMZ) prevents many opportunistic infections, including infection with P. carinii, Toxoplasma gondii, and community-acquired respiratory, gastrointestinal, and urinary tract pathogens. Intolerance of TMP-SMZ is common; desensitization is useful less often in transplant patients than in patients with AIDS. Alternative agents provide a narrower spectrum of protection than does TMP-SMZ and less adequate protection against Pneumocystis species. Clinically, the diagnosis of breakthrough Pneumocystis pneumonia often requires invasive procedures. Strategies for the prevention of Pneumocystis infection must be individualized on the basis of a stratification of risk for each patient.