A prospective study of discontinuing primary and secondary Pneumocystis carinii pneumonia prophylaxis after CD4 cell count increase to > 200 x 106 /l

Pneumocystis jirovecii pneumonia in people living with HIV: a review

Pneumocystis jirovecii is a ubiquitous opportunistic fungus that can cause life-threatening pneumonia. People with HIV (PWH) who have low CD4 counts are one of the populations at the greatest risk of Pneumocystis jirovecii pneumonia (PCP). While guidelines have approached the diagnosis, prophylaxis, and management of PCP, the numerous studies of PCP in PWH are dominated by the 1980s and 1990s. As such, most studies have included younger male populations, despite PCP affecting both sexes and a broad age range. Many studies have been small and observational in nature, with an overall lack of randomized controlled trials. In many jurisdictions, and especially in low- and middle-income countries, the diagnosis can be challenging due to lack of access to advanced and/or invasive diagnostics. Worldwide, most patients will be treated with 21 days of high-dose trimethoprim sulfamethoxazole, although both the dose and the duration are primarily based on historical practice. Whether treatment with a lower dose is as effective and less toxic is gaining interest based on observational studies. Similarly, a 21-day tapering regimen of prednisone is used for patients with more severe disease, yet other doses, other steroids, or shorter durations of treatment with corticosteroids have not been evaluated. Now with the widespread availability of antiretroviral therapy, improved and less invasive PCP diagnostic techniques, and interest in novel treatment strategies, this review consolidates the scientific body of literature on the diagnosis and management of PCP in PWH, as well as identifies areas in need of more study and thoughtfully designed clinical trials.

Bacterial Infections in Adult HIV-Infected Patients

PURPOSE

The purpose of this article is to critically review articles published from the pre-HAART era to the present on bacterial infections in adult HIV-infected patients.

METHOD

Literature search on bacterial infections in HIV-infected patients yields predominantly small case series from single centers, many of which are retrospectively collected.

RESULTS

Variations in case selection limit the utility of these articles for assessing the epidemiology and clinical features of a particular infection. Nonetheless, numerous articles indicate that certain bacterial infections occur most often when CD4 cell counts are < 200/mm3. In the pre-HAART era, others suggest that PcP prophylaxis with TMP/SMX and MAC prophylaxis with macrolides reduced rates of several bacterial infections. Since the advent of HAART, however, some articles suggest that the incidence of various infections has declined and that withdrawal of OI prophylaxis in patients who have had HAART restoration of CD4 cell counts has not led to an increase in certain bacterial infections.

CONCLUSION

This review suggests that bacterial infections may have declined in the HAART era, as multicenter cohort studies have shown to be the case with AIDS-associated OIs. Nonetheless, preventive measures such as pneumococcal vaccination and smoking cessation remain effective strategies.

Discontinuation of primary and secondary prophylaxis for opportunistic infections in HIV-infected patients who had CD4+ cell count <200 cells/mm(3) but undetectable plasma HIV-1 RNA: an open-label randomized controlled trial

Abstract The CDC recommends discontinuing opportunistic infections (OIs) prophylaxis in HIV-infected patients who have CD4+ cell count >200 cells/mm(3) after receiving combination antiretroviral therapy (cART). A prospective randomized controlled trial was conducted at Chiang Mai University Hospital from June 1, 2009 to January 31, 2012 in 74 adult HIV-infected patients who had received cART and had CD4+ cell count <200 cells/mm(3) but plasma HIV-1 RNA<50 copies/ml. Forty-three patients (58.1%) were male and the mean age was 41.8±8.1 years; 68 (91.9%) and 59 (79.7%) patients were receiving co-trimoxazole and antifungal prophylaxis, respectively. The median CD4+ cell counts at enrollment were 142 (IQR 108, 161) and 158 (IQR 141, 176) cells/mm(3) among patients who discontinued and continued OIs prophylaxis, respectively (p value=0.041). One of 37 patients (2.7%) in the discontinuation group developed Pneumocystis jiroveci pneumonia, giving the incidence rate of 1.57/1000 person-months. None of the 37 patients in the continuation group developed OIs. The difference in the prevention rates of OIs between groups was -2.7% (95% CI -7.9, 2.5). In conclusion, in the setting where plasma HIV-RNA measurement is available, e.g., Asia-Pacific region, discontinuation of prophylaxis is considerably safe in HIV-infected patients receiving cART with undetectable plasma HIV-RNA but incomplete immune recovery.

Risk of pneumocystosis after early discontinuation of prophylaxis among HIV-infected patients receiving highly active antiretroviral therapy

BACKGROUND

Risk of pneumocystosis after discontinuation of primary or secondary prophylaxis among HIV-infected patients before CD4 counts increase to >==200 cells/microL (early discontinuation) after receiving highly active antiretroviral therapy (HAART) is rarely investigated.

METHODS

Medical records of 660 HIV-infected patients with baseline CD4 counts <200 cells/microL who sought HIV care and received HAART at a university hospital in Taiwan between 1 April, 1997 and 30 September, 2007 were reviewed to assess the incidence rate of pneumocystosis after discontinuation of prophylaxis for pneumocystosis.

RESULTS

The incidence rate of pneumocystosis after HAART was 2.81 per 100 person-years among 521 patients who did not initiate prophylaxis or had early discontinuation of prophylaxis, which was significantly higher than the incidence rate of 0.45 per 100 person-years among 139 patients who continued prophylaxis until CD4 counts increased to >==200 cells/microL (adjusted risk ratio, 5.32; 95% confidence interval, 1.18, 23.94). Among the 215 patients who had early discontinuation of prophylaxis after achievement of undetectable plasma HIV RNA load, the incidence rate of pneumocystosis was reduced to 0.31 per 100 person-years, which was similar to that of the patients who continued prophylaxis until CD4 counts increased to >==200 cells/microL (adjusted risk ratio, 0.63; 95% confidence interval, 0.03, 14.89).

CONCLUSIONS

Compared with the risk of pneumocystosis among patients who continued prophylaxis until CD4 counts increased to >==200 cells/microL after HAART, the risk was significantly higher among patients who discontinued prophylaxis when CD4 counts remained <200 cells/microL, while the risk could be reduced among patients who achieved undetectable plasma HIV RNA load after HAART.

Risk factors of Pneumocystis jeroveci pneumonia in patients with systemic lupus erythematosus

Pneumocystis jeroveci pneumonia (PCP) is an opportunistic infection which occurs mostly in the immune-deficiency host. Although PCP infected systemic lupus erythematosus (SLE) patient carries poor outcome, no standard guideline for prevention has been established. The aim of our study is to identify the risk factors which will indicate the PCP prophylaxis in SLE. This is a case control study. A search of Ramathibodi hospital's medical records between January 1994 and March 2004, demonstrates 15 cases of SLE with PCP infection. Clinical and laboratory data of these patients were compared to those of 60 matched patients suffering from SLE but no PCP infection. Compared to SLE without PCP, those with PCP infection have significantly higher activity index by MEX-SLEDAI (13.6 +/- 5.83 vs. 6.73 +/- 3.22) or more renal involvement (86 vs. 11.6%, P < 0.01), higher mean cumulative dose of steroid (49 +/- 29 vs. 20 +/- 8 mg/d, P < 0.01), but lower lymphocyte count (520 +/- 226 vs. 1420 +/- 382 cells/mm(3), P < 0.01). Interestingly, in all cases, a marked reduction in lymphocyte count (710 +/- 377 cells/mm(3)) is observed before the onset of PCP infection. The estimated CD4+ count is also found to be lower in the PCP group (156 +/- 5 vs. 276 +/- 8 cells/mm(3)). Our study revealed that PCP infected SLE patients had higher disease activity, higher dose of prednisolone treatment, more likelihood of renal involvement, and lower lymphocyte count as well as lower CD4+ count than those with no PCP infection. These data should be helpful in selecting SLE patients who need PCP prophylaxis.

Clinical applications and availability of CD4+ T cell count testing in sub-Saharan Africa

The absolute CD4+ T cell count in adults and CD4+ T cell percentage of lymphocytes (CD4%) in pediatrics compliment clinical history and physical examination to inform decisions about initiating antiretroviral therapy (ART). In addition, these immunologic markers predict host susceptibility to specific opportunistic infections, selected drug toxicities, and mortality. These benefits argue strongly for the availability of CD4+ T cell testing capacity in all settings where HIV infection is treated. Several currently available flow cytometry-based devices, and novel CD4+ T cell enumeration techniques such as the panleucogating CD4 are especially suitable for resource-constrained settings. At this time, unfortunately, the landscape of HIV care in sub-Saharan Africa is a mosaic characterized by large areas where CD4+ T cell testing capacity is limited or unavailable, and small, but growing, pockets where the capacity exists. Routine HIV quantification is currently unaffordable and unsustainable in the great majority of the region; therefore, a reliance on CD4+ T cell testing is inevitable for now. To this end, correcting the disparities in CD4+ T cell testing capacity and defining the minimum laboratory requirements for the safe use of antiretroviral drugs through well-designed clinical studies are some of the most urgent priorities of the ongoing global scale-up of ART.

Prophylaxis against Pneumocystis pneumonia in patients with inflammatory bowel disease: toward a standard of care

Patients with Crohn's Disease and ulcerative colitis are increasingly treated with a host of immunomodulatory and immunosuppressive medications, including thiopurines and antibody-based biologic agents. Despite the known infectious complications associated with these therapies from the HIV and solid organ transplant literature, there are currently no well-defined concise guidelines to assist gastroenterologists and other physicians in the utility and indication for prophylaxis against Pneumocystis pneumonia and other infections in inflammatory bowel disease (IBD) patients. In this article, we discuss the evidence of various infections associated with immunocompromise in HIV/AIDS, organ transplantation, and in other immunocompromised states, and discuss the evidence for the efficacy and safety of various infectious prophylaxis protocols. In addition, we discuss the evidence for Pneumocystis and other infections in IBD patients treated with corticosteroids, azathioprine/6-MP, biologic agents and other therapies, and we present the case for various antibiotic (and antiviral) regimens to prevent such infections. Based on the review of the literature, this discussion represents a true call for guidelines for infection prophylaxis, to help guide gastroenterologists and all practitioners who care for the challenging population of IBD patients.

Pneumocystis jiroveci pneumonia prophylaxis is not required with a CD4+ T-cell count < 200 cells/microl when viral replication is suppressed

OBJECTIVE

To determine the safety of discontinuing Pneumocystis jiroveci pneumonia (PCP) prophylaxis, in patients on effective antiretroviral therapy with CD4+ T-cell counts that have plateaued at < 200 cells/microl.

METHODS

We prospectively evaluated a cohort of HIV infected patients at a multidisciplinary HIV clinic with sustained HIV RNA levels < 50 copies/ml and CD4+ T-cell counts that have plateaued at < 200 cells/microl and who have discontinued PCP prophylaxis.

RESULTS

Nineteen patients fulfilled the above criteria. Eleven had been taking daily trimethoprim-sulfamethoxazole, seven were receiving monthly aerosolized pentamidine, and one patient never received any prophylaxis. The median CD4+ T-cell count at the time of discontinuation and at the most recent determination were 120 (range, 34-184) and 138 (range, 6-201) cells/microl, respectively. To date, patients have been off PCP prophylaxis for a mean of 13.7 +/- 10.6 months and a median of 9.0 (range 3-39) months for a total of 261 patient-months. To date, no patient has developed PCP. This is significantly different from the risk of developing PCP with a CD4+ T-cell count of < 200 cells/microl in untreated HIV infection (rate difference 9.2%; 95% confidence interval, 5.7 to 12.8%; P < 0.05).

CONCLUSION

With sustained suppression of viral replication, PCP prophylaxis may not be necessary, regardless of CD4+ T-cell count. This illustrates a degree of immune recovery that occurs with virologic suppression that is not reflected in absolute CD4+ T-cell count or percentage and suggests that guidelines for P. jiroveci pneumonia prophylaxis may need to be re-evaluated.

Lower CD4+ T lymphocyte nadirs may indicate limited immune reconstitution in HIV-1 infected individuals on potent antiretroviral therapy: analysis of immunophenotypic marker results of AACTG 5067

BACKGROUND

Although initiation of potent antiretroviral therapy (ART) has significantly improved immune perturbations in individuals with AIDS, it is unclear which factors are most important in determining the degree of immune reconstitution.

METHODS

Whole blood was analyzed at baseline and week 12 in six groups of subjects (n = 81): those with acute or following immune reconstitution after Pneumocystis jirovecii (previously known as Pneumocystis carinii) pneumonia (PcP) (two groups) and cytomegalovirus (CMV) retinitis (two groups), HIV-infection without AIDS (one group), and healthy volunteers (one group). Absolute CD4+ and CD8+ T lymphocytes, naive (CD45RA+) and memory (CD45RO+) CD4+ T lymphocytes and percentages of activated CD8+ T lymphocytes (CD8+/CD38+/HLA-DR), and CD28 expression on CD4+ and CD8+ T lymphocytes were enumerated.

RESULTS

The reconstituted CMV group, which had a history of a lower CD4+ T lymphocyte nadir compared to the reconstituted PcP group (15 cells/mm(3) versus 48 cells/mm(3); p = .013), had significantly lower absolute CD4+, CD8+ and naive CD4+ T lymphocytes and a trend toward lower memory CD4+ T lymphocytes compared to the reconstituted PcP group. Moreover, no difference was noted between the reconstituted groups in the proportion of subjects with undetected HIV-1 RNA. The reconstituted subjects had significantly lower absolute CD4+, memory CD4+ and naive CD4+ T lymphocytes than the HIV-positive controls and a significantly higher percentage of activated CD8+ T lymphocytes with a lower percentage of CD8+CD28 expression than the HIV-negative controls.

CONCLUSION

The association of CD4+ T lymphocyte nadir with the extent of immune reconstitution in HIV-infected individuals suggests that HIV-1 may cause irreparable immune system damage despite potent ART.

Long-term antifungal prophylaxis in high-risk hematopoietic stem cell transplant recipients

The risks for invasive fungal infections, particularly mould infections such as invasive aspergillosis, among hematopoietic stem cell transplant (HSCT) recipients are linked to the duration and severity of myelosuppression and immunosuppression. Strategies to prevent invasive fungal infections have focused primarily on the use of orally administered azole antifungal agents during the neutropenic period rather than on the more prolonged post-engraftment period. The major limitations of these studies included the heterogeneity among the subjects studied for fungal infection risk factors, the agents administered, the dosing, and duration of prophylaxis. More recent studies have attempted to examine the efficacy of antifungal prophylaxis strategies among allogeneic HSCT recipients to day 100 and beyond. It is clear that a variety of products have efficacy in preventing invasive candidiasis, including imidazole and triazole antifungals, low-dose amphotericin B, and the echinocandin, micafungin; however, only the extended spectrum azole, itraconazole, has been shown to impact the incidence of proven invasive aspergillosis. Other extended spectrum azole antifungal agents, voriconazole and posaconazole, are being studied as long-term prophylaxis in high-risk HSCT recipients. While clinical trials have suggested that a duration of prophylaxis against moulds of six months or more may be required, it remains unclear if this is required in all cases. The prophylactic efficacy over time may be linked to the degree of immunosuppression as measured by markers such as the numbers of circulating CD4 T lymphocytes. Concerns about selection for resistant moulds among long-term recipients of these drugs are emerging. The cumulative experience to date suggests that long-term antifungal chemoprophylaxis is feasible and effective when applied in defined circumstances. The concerns about treatment-related toxicities, resistance, and costs are valid.

Long-Term Follow-Up of HIV-Infected Individuals Who Have Significant Increases in CD4+ Cell Counts during Antiretroviral Therapy

BACKGROUND

Descriptions of the durability and consequences of immune reconstitution in patients who start highly active antiretroviral therapy (HAART) while severely immunosuppressed are limited.

METHODS

Patients with previous CD4+ cell counts <50 cells/mm3, all of whom had HAART-induced increases in CD4+ cell counts of >100 cells/mm3 on 2 separate occasions (measured sequentially at least 4 weeks apart), were enrolled in a prospective trial and observed every 16-32 weeks. Evaluations included assessments for new opportunistic complications, virologic (human immunodeficiency virus [HIV] RNA load) and immunologic (CD4+ cell count) responses, or death.

RESULTS

The median follow-up duration for 612 subjects was 184 weeks (range, 8-216 weeks). The rate of increase in CD4+ cell counts was approximately 5.9 cells/mm3 every 8 weeks, with the degree of increase associated with the baseline HIV RNA load (<500 vs. > or =500 copies/mL). Subsequent measurements of virologic suppression based on HIV RNA levels were also associated with predicted CD4+ cell responses. Thirty-three AIDS-defining illnesses were reported (1.75 events per 100 person-years of follow-up); >40% (14 cases) occurred with higher than expected CD4+ cell counts.

CONCLUSIONS

CD4+ cell count increases are related to virological control, with continuing increases seen in individuals who are immunosuppressed. Opportunistic illnesses and/or complications are infrequent but can occur at any time, even in patients who maintained an elevated CD4+ cell count.

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.

Safety of Discontinuation of Maintenance Therapy for Disseminated Histoplasmosis after Immunologic Response to Antiretroviral Therapy

We performed a prospective observational study to assess the safety of stopping maintenance therapy for disseminated histoplasmosis among human immunodeficiency virus infected patients after response to antiretroviral therapy. All subjects received at least 12 months of antifungal therapy and 6 months of antiretroviral therapy before entry. Negative results of fungal blood cultures, urine and serum Histoplasma antigen level of <4.1 units, and CD4+ T cell count of >150 cells/mm3 were required for eligibility. Thirty-two subjects were enrolled; the median CD4+ T cell count at study entry was 289 cells/mm3. No relapses of histoplasmosis occurred after a median duration of follow-up of 24 months. This corresponded to an observed relapse rate of 0 cases per 65 person-years. The median CD4+ T cell count at final study visit was 338 cells/mm3. Discontinuation of antifungal maintenance therapy appears to be safe for patients with acquired immunodeficiency syndrome with previously treated disseminated histoplasmosis and sustained immunologic improvement in response to antiretroviral therapy.

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.

Low incidence of community-acquired pneumonia among human immunodeficiency virus-infected patients after interruption of Pneumocystis carinii pneumonia prophylaxis

We compared the incidence of bacterial pneumonia among 336 patients who discontinued trimethoprim-sulfamethoxazole (TMP-SMX) as prophylaxis against Pneumocystis carinii pneumonia (PCP) with that among 75 patients who fulfilled the criteria for discontinuation but continued receiving prophylaxis. The difference in the overall incidence rates for the 2 groups (1.2 events per 100 person-years) was not statistically significant. Discontinuation of TMP-SMX prophylaxis against PCP is not associated with a significant increase in the incidence of bacterial pneumonia among patients with a sustained CD4 cell count increase to >200 cells/microL.

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.

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.