Discontinuation of primary prophylaxis against Pneumocystis carinii pneumonia in HIV-1-infected adults treated with combination antiretroviral therapy. Swiss HIV Cohort Study

Epidemiology of human immunodeficiency virus-associated opportunistic infections in the United States in the era of highly active antiretroviral therapy

The incidence of nearly all AIDS-defining opportunistic infections (OIs) decreased significantly in the United States during 1992-1998; decreases in the most common OIs (Pneumocystis carinii pneumonia ¿PCP, esophageal candidiasis, and disseminated Mycobacterium avium complex ¿MAC disease) were more pronounced in 1996-1998, during which time highly active antiretroviral therapy (HAART) was introduced into medical care. Those OIs that continue to occur do so at low CD4+ T lymphocyte counts, and persons whose CD4+ counts have increased in response to HAART are at low risk for OIs, a circumstance that suggests a high degree of immune reconstitution associated with HAART. PCP, the most common serious OI, continues to occur primarily in persons not previously receiving medical care. The most profound effect on survival of patients with AIDS is conferred by HAART, but specific OI prevention measures (prophylaxis against PCP and MAC and vaccination against Streptococcus pneumoniae) are associated with a survival benefit, even when they coincide with the administration of HAART. Continued monitoring of incidence trends and detection of new syndromes associated with HAART are important priorities in the HAART era.

[Effect of antiretroviral treatment and prophylaxis for opportunistic infections on survival of patients with AIDS]

OBJECTIVE

To analyze the influence of anti-retroviral therapy (ART) and prophylaxis against opportunist disease on survival of patients with AIDS.

PATIENTS AND METHODS

Study of AIDS patients diagnosed from January 1996 to October 1997 in a Madrid hospital. An analysis was made of demographic, clinical, and immunological data, as well as ART and prophylaxis against Pneumocystis carinii pneumonia (PCP) and tuberculosis (TB). Both univariate and multivariate analyses were performed, as well as Kaplan-Meier curves.

RESULTS

A total of 205 patients were included in the study (83% male) with a median age of 34 years. ART, PCP prophylaxis, and TB prophylaxis were received by 147 (72%), 141 (69%) and 22 (11%) patients, respectively. Among individuals on ART, the likelihood of survival at 12 and 22 months since diagnosis of AIDS was made was 79% and 76%, respectively, and among non treated individuals 54% and 54%, respectively (p < 0.05). ART was associated with a 57% decrease in death risk, and regarding PCP prophylaxis, no benefit on survival was found.

CONCLUSIONS

ART was significantly associated with a lower risk of death among AIDS patients. The survival rate was not increased with PCP prophylaxis.

Discontinuation of secondary prophylaxis for opportunistic infections in HIV-infected patients receiving highly active antiretroviral therapy

BACKGROUND

Immune reconstitution following the introduction of highly active antiretroviral therapies (HAART) has lead to a remarkable reduction in the incidence of opportunistic infections (OI) in subjects with advanced HIV disease. Moreover, discontinuation of primary prophylaxis for some OI can be attempted without risk in patients experiencing a favourable response to treatment. However, data on the feasibility of discontinuing secondary prophylaxis are much more scarce, and restricted mainly to the withdrawal of maintenance treatment for cytomegalovirus (CMV) retinitis.

PATIENTS AND METHODS

Retrospective review of the clinical outcome at 18 months in HIV-infected patients in whom discontinuation of secondary prophylaxis, for different OI, was recommended 3 months after the introduction of HAART, if both CD4 counts > 100 x 10(6) CD4 lymphocytes/l and plasma HIV-RNA < 500 copies/ml had been achieved.

RESULTS

Fifty-three subjects were analysed. Secondary chemoprophylaxis was discontinued for the following OI: Pneumocystis carinii pneumonia (PCP) (n = 29), cerebral toxoplasmosis (n = 9), disseminated Mycobacterium avium complex infection (n = 7), CMV retinitis (n = 5), recurrent oroesophageal candidiasis (n = 5), Visceral leishmaniasis (n = 2), recurrent herpes zoster (n = 2), and chronic mucocutaneous herpes simplex infection (n = 1). In six individuals, OI prophylaxis was discontinued for two or more entities. Only two episodes of OI were recorded in these individuals during 18 months of follow-up. One developed tuberculous lymphadenitis despite having a good response to treatment, and another suffered a new episode of PCP after voluntary treatment interruption for 6 weeks.

CONCLUSION

Secondary prophylaxis for OI can be attempted without major risk in HIV-infected patients experiencing a favourable response to HAART. The benefit of this intervention should reduce costs, drug side-effects and pharmacologic interactions, and indirectly will improve patient's quality of life and adherence to antiretroviral treatment.

Opportunistic infections and other clinical manifestations of HIV disease in children

As the decade draws to a close, physicians can be cautiously optimistic about the prevention and treatment of opportunistic infections in children with HIV disease. As more children receive therapy with powerful antiretroviral regimens, fewer are likely to be at risk for opportunistic pathogens. The widespread use of protease inhibitor combination therapies has already resulted in a dramatic decrease in morbidity and mortality in the population of HIV-infected adults. The same effect has been seen at pediatric care centers throughout the United States. Clinicians caring for HIV-infected children are now considering the safety of discontinuing prophylactic therapies for children with sustained immunologic improvement on antiretroviral therapy. For children who remain at risk, prophylactic regimens for PCP and MAC have been shown to decrease the risk for these infections. Preventive regimens for several other opportunistic infections are also available. The understanding of the pathogenesis of HIV and many of the opportunistic pathogens has led to the development of a variety of efficacious therapies for these infections. Despite these advances, physicians can anticipate that HIV-infected children will continue to develop opportunistic infections and other related complications. Some children fail to respond to antiretroviral therapies, whereas others are unable to tolerate the complex medication regimens. Prophylactic therapies are not 100% protective and, despite improved treatments, few opportunistic infections are cured. Most require lifelong maintenance therapy in the absence of immune reconstitution. Drug interactions, complex dosing schedules, adverse side effects, and high costs further limit the efficacy of these therapies. The prophylaxis, diagnosis, and treatment of opportunistic infections are likely to remain integral components of HIV care for the near and distant future.

Discontinuation of chemoprophylaxis against Pneumocystis carinii pneumonia in patients with HIV infection. HIV Outpatient Study (HOPS) Investigators

BACKGROUND

HIV-infected patients with sustained immunologic improvement from antiretroviral therapy may be able to discontinue chemoprophylaxis against Pneumocystis carinii pneumonia (PCP).

OBJECTIVE

To compare PCP incidence in HIV-infected patients who had sustained CD4+ lymphocyte counts greater than 200 cells/mm3 and who either discontinued or continued PCP prophylaxis.

DESIGN

Nonrandomized prospective cohort study.

SETTING

10 HIV clinics in eight U.S. cities.

PATIENTS

146 patients had follow-up visits for a mean of 18.2 months after discontinuation of PCP prophylaxis, and 345 patients who continued PCP prophylaxis had follow-up visits for a mean of 14.0 months.

MEASUREMENTS

Incidence of PCP.

RESULTS

Patients who discontinued PCP prophylaxis had higher maximum and minimum CD4+ cell counts and lower vira loads than patients who continued PCP prophylaxis. Pneumocystis carinii pneumonia did not develop in either group (upper 95% exact binomial confidence limit of incidence for those who discontinued PCP prophylaxis, 2.3/100 person-years).

CONCLUSIONS

Discontinuation of PCP chemoprophylaxis may be appropriate for some HIV-infected ambulatory patients.

CMV retinitis recurs after stopping treatment in virological and immunological failures of potent antiretroviral therapy

OBJECTIVES

To determine predictors of clinical relapse of cytomegalovirus (CMV) end-organ disease in a cohort of 17 HIV-infected patients with healed and treated CMV retinitis (CMVR) who responded to HAART with an increase in CD4 cell counts to above 70 cells/mm3 and discontinued CMV maintenance therapy (MT).

DESIGN

Seventeen patients were monitored for reactivation of retinitis. The CD4 cell counts, HIV RNA and peripheral blood mononuclear cell (PBMC) lymphoproliferative assays to CMV at 3 month intervals were compared between patients with and without reactivation of CMVR. Positive lymphoproliferative responses were defined as a stimulation index of 3 or greater.

RESULTS

Five out of 17 (29%) patients experienced a recurrence of CMVR a mean of 14.5 months after stopping CMV MT and between 8 days and 10 months after CD4 cell counts fell below 50 cells/mm3. Median CD4 cell counts and plasma HIV RNA at reactivation were 37 cells/mm3 and 5.3 log10 copies/ml. Three patients recurred at a previously active site of the retina, one had contralateral CMVR, and one a recurrence of retinitis and pancreatitis simultaneously. Mean lymphoproliferative responses to CMV were 2.4 in patients with reactivation versus 21.0 stimulation index (SI) in patients without reactivation (P= 0.01). A model incorporating four variables (CD4 cell counts and HIV RNA at maintenance discontinuation, highest CD4 cell count, nadir HIV RNA and median lymphoproliferative responses) identified correctly 88% of patients with and without reactivation.

CONCLUSION

CMV disease recurs after virological and immunological failure of HAART if CD4 cell counts drop below 50. In this situation, anti-CMV agents should be resumed before clinical reactivation ensues, because of the risk of contralateral retinal involvement and systemic disease.

Clinical and immunologic response without decrease in virus load in patients with AIDS after 24 months of highly active antiretroviral therapy

This study reports an analysis of clinical, virological, and immunologic outcomes in a cohort of 77 multidrug-experienced AIDS patients during 24 months of highly active antiretroviral therapy (HAART). Our results have shown a reduced risk of AIDS complications, prolonged survival, and immunologic benefit even in the absence of sustained virus suppression. The degree of immunodepression, the risk factors for HIV-1 infection, the use of 2 drugs instead of 3, and a change in protease inhibitor were independently correlated with virological failure. In the majority of studied patients, an increase in CD4+ T cells was observed after HAART. However, the increase was more pronounced in patients who showed a decrease in virus load than in those who did not. Moreover, we observed an absence of relapses among patients who permanently discontinued prophylaxis for Cytomegalovirus retinitis and atypical mycobacterial infections. Peripheral lipodystrophy developed in the majority of patients, regardless of treatment used and virological outcome.

Can chemoprophylaxis against opportunistic infections be discontinued after an increase in CD4 cells induced by highly active antiretroviral therapy?

BACKGROUND

In the 'USPHS/IDSA Guidelines for Prevention of Opportunistic Infections in Persons Infected with Human Immunodeficiency Virus', the indications for chemoprophylaxis are based on nadir CD4 cell count. Many patients have, however, experienced an increase in CD4 cell count after the introduction of highly active antiretroviral therapy (HAART).

OBJECTIVES

To assess incidences of opportunistic infections after discontinuation of chemoprophylaxis in HIV-infected patients, who have experienced a HAART-induced increase in CD4 cell count.

METHODS

The Danish guidelines for chemoprophylaxis against opportunistic infections in HIV-infected patients were revised in late 1997, allowing discontinuation of chemoprophylaxis after initiation of HAART if the CD4 cell count remained above a specified limit for more than 6 months. Consecutive patients were followed, and incidences of opportunistic infections after discontinuation of chemoprophylaxis were assessed.

RESULTS

A total of 219 patients discontinued Pneumocystis carinii pneumonia (PCP)-chemoprophylaxis (12% maintenance therapy). One case of PCP was diagnosed within 174 person-years (PY) of follow-up, resulting in an incidence of 0.6 cases/100 PY follow-up (95% confidence interval, 0.0-3.2). No cases of cerebral toxoplasmosis, cytomegalovirus chorioretinitis, or disseminated Mycobacterium avium infection were observed. Follow-up time for these was, however, limited.

CONCLUSION

PCP-chemoprophylaxis can be safely discontinued after HAART-induced increase in CD4 cell count to more than 200 x 10(6) cells/l. Among consecutive patients who discontinue chemoprophylaxis according to well-defined guidelines, the observed incidence of PCP is below those reported earlier in patients with similar CD4 cell count.

Immune reconstitution in HIV-1 infected subjects treated with potent antiretroviral therapy

The introduction of potent antiretroviral drug regimens contributed to a decline in HIV-1 associated morbidity and mortality. Clinical observations of spontaneous remission of previously untreatable opportunistic infections in subjects on highly active antiretroviral therapy (HAART) reflect the substantial degree of immune reconstitution which can be achieved by those therapies. A biphasic increase of CD4+ T lymphocytes has been reported including naive (CD45RA+) and memory (CD45RO+) cell subsets. Proliferative lymphocyte responses to recall antigens and mitogens are enhanced over time, while T lymphocyte activation is largely reduced and T cell receptor (TCR) repertoires are partly restored. Proliferative lymphocyte responses specific to HIV-1 antigens, in contrast, remain weak. A complete normalisation of HIV-1 associated immunological alterations has not been reported so far, but the observation period of subjects on potent antiretroviral therapies is still relatively short.