Systemic inflammatory reaction after starting highly active antiretroviral therapy in AIDS patients treated for extrapulmonary tuberculosis

Paradoxical Reactions and the Immune Reconstitution Inflammatory Syndrome

In HIV-infected individuals, paradoxical reactions after the initiation of antiretroviral therapy (ART) are associated with a variety of underlying infections and have been called the immune reconstitution inflammatory syndrome (IRIS). In cases of IRIS associated with tuberculosis (TB), two distinct patterns of disease are recognized: (i) the progression of subclinical TB to clinical disease after the initiation of ART, referred to as unmasking, and (ii) the progression or appearance of new clinical and/or radiographic disease in patients with previously recognized TB after the initiation of ART, the classic or "paradoxical" TB-IRIS. IRIS can potentially occur in all granulomatous diseases, not just infectious ones. All granulomatous diseases are thought to result from interplay of inflammatory cells and mediators. One of the inflammatory cells thought to be integral to the development of the granuloma is the CD4 T lymphocyte. Therefore, HIV-infected patients with noninfectious granulomatous diseases such as sarcoidosis may also develop IRIS reactions. Here, we describe IRIS in HIV-infected patients with TB and sarcoidosis and review the basic clinical and immunological aspects of these phenomena.

Prevention of HIV-associated opportunistic infections and diseases in the age of highly active antiretroviral therapy

Since the introduction of highly active antiretroviral therapy (HAART), the rates of opportunistic infections have decreased markedly as has overall morbidity and mortality from HIV infection in developed countries. However, opportunistic infections remain the most important cause of death in HIV-infected people due to both late presentation of HIV infections and failure of HAART to adequately restore cell-mediated immunity in all individuals. While prophylaxis may be discontinued in patients who have responded to HAART with sustained increases of their CD4 counts above risk thresholds, for those patients who fail HAART, those who are unable to tolerate it, or whose treatments are interrupted, opportunistic-infection prophylaxis remains essential. Some HIV-associated diseases, such as anogenital human papilloma virus-induced neoplasia and hepatitis C infection, have not decreased in frequency with the advent of HAART. For these conditions, effective screening and treatment programs will be necessary to prevent ongoing morbidity. This review will provide an update on HIV-associated opportunistic infections and their prevention in the age of HAART, as well as discuss novel presentations of opportunistic illnesses, such as immune restoration syndromes.

Incidence and risk factors of immune reconstitution inflammatory syndrome in HIV-TB coinfected patients

Tuberculosis is one of the leading causes of development of Immune reconstitution inflammatory syndrome (IRIS) in HIV patients receiving antiretroviral therapy (ART).

OBJECTIVE

To determine the incidence of IRIS in HIV-TB coinfected patients, and to find out the possible risk factors associated with IRIS.

MATERIALS AND METHODS

Study commenced with 96 patients adhered to standard antitubercular therapy (ATT) and ART without defaulting, and followed up for six months.

RESULT

The mean (± SD) CD4 count and CD4 percentage at baseline was 59.16 (± 24.63) per mm³ and 4.59% (± 1.73) respectively. Only 18.75% developed IRIS after 57.05 (± 14.12) days of initiation of ART. Extrapulmonary tuberculosis was the most significant factor associated with IRIS (83.33%) than those without IRIS (44.87%) (p = 0.0032). Specifically, tubercular lymphadenitis (38.88%, p = 0.0364) and disseminated tuberculosis (33.33%, p = 0.0217) were significantly associated with IRIS. The other risk factors associated with appearance of IRIS were higher CD4 count (p = 0.0212) at three months after initiation of ART and increment of CD4 count (p = 0.0063) and CD4 percentage (p = 0.0016) during this period. The major manifestations of IRIS were fever (40%), followed by lymphadenitis (38%). The mortality rate in IRIS was not higher than those without IRIS.

CONCLUSION

Patients with extrapulmonary tuberculosis, especially tubercular lymphadenitis, were more likely to develop IRIS and fever was associated in most of them. Higher increment of CD4 count may indicate development of IRIS in presence of new or worsening tuberculosis lesion.

Cerebral Mycobacterium avium abscesses: Late immune reconstitution syndrome in an HIV-1-infected patient receiving highly active antiretroviral therapy

A patient who developed an atypical manifestation of Mycobacterium avium complex (MAC) infection almost two years after starting effective highly active antiretroviral therapy is described. The recurrence, manifested as brain abscesses in the central nervous system, was an uncommon form of MAC disease usually reported postmortem. An increased CD4 cell count, localized and suppurative infection, and the absence of systemic evidence of infection were consistent with a late immune reconstitution syndrome. The present case report adds to the understanding of MAC disease in HIV-infected patients.

Pediatric HIV immune reconstitution inflammatory syndrome

PURPOSE OF REVIEW

Little is known regarding HIV immune reconstitution inflammatory syndrome in children. As the antiretroviral therapy roll out has gathered pace since 2004 in resource-limited settings, pediatric immune reconstitution inflammatory syndrome has emerged as a clinical challenge.

RECENT FINDINGS

The incidence of immune reconstitution inflammatory syndrome appears to be between 10 and 20%. The commonest causes are mostly mycobacterial, including tuberculosis, atypical mycobacteria and bacillus Calmette-Guérin related. In many pediatric cohorts, however, a marked early mortality within the first 90 days of antiretroviral therapy occurs. This mortality is poorly understood, and the contribution of immune reconstitution inflammatory syndrome to this mortality is unknown.

SUMMARY

Children after starting antiretroviral therapy may have paradoxical worsening of previously treated opportunistic infections. Due to the differences, however, in children's immunology with vertical HIV transmission, children are probably at greater risk of unmasking occult, subclinical infections during immune reconstitution.

Immune reconstitution inflammatory syndrome in association with HIV/AIDS and tuberculosis: views over hidden possibilities

Gut immune components are severely compromised among persons with AIDS, which allows increased translocation of bacterial lipopolysaccharides (LPS) into the systemic circulation. These microbial LPS are reportedly increased in chronically HIV-infected individuals and findings have correlated convincingly with measures of immune activation. Immune reconstitution inflammatory syndrome (IRIS) is an adverse consequence of the restoration of pathogen-specific immune responses in a subset of HIV-infected subjects with underlying latent infections during the initial months of highly active antiretroviral treatment (HAART). Whether IRIS is the result of a response to a high antigen burden, an excessive response by the recovering immune system, exacerbated production of pro-inflammatory cytokines or a lack of immune regulation due to inability to produce regulatory cytokines remains to be determined. We theorize that those who develop IRIS have a high burden of proinflammatory cytokines produced also in response to systemic bacterial LPS that nonspecifically act on latent mycobacterial antigens. We also hypothesize that subjects that do not develop IRIS could have developed either tolerance (anergy) to persistent LPS/tubercle antigens or could have normal FOXP3+ gene and that those with defective FOXP3+ gene or those with enormous plasma LPS could be vulnerable to IRIS. The measure of microbial LPS, anti-LPS antibodies and nonspecific plasma cytokines in subjects on HAART shall predict the role of these components in IRIS.

Late Presentation of HIV-Infected Individuals

Late presentation remains a major concern despite the dramatically improved prognosis realized by ART. We define a first presentation for HIV care during the course of HIV infection as ‘late’ if an AIDS-defining opportunistic disease is apparent, or if CD4+ T-cells are <200/μl. In the Western world, approximately 10 and 30% of HIV-infected individuals still present with CD4+ T-cells <50 and <200/μl, respectively; estimates are substantially higher for developing countries. Diagnosis and treatment of opportunistic diseases and intense supportive in-hospital care take precedence over ART. Benefits of starting ART without delay, that is, when opportunistic diseases are still active, include faster resolution of opportunistic diseases and a decreased risk of recurrence. The downside of starting ART without delay could include toxicity, drug interactions and immune reconstitution inflammatory syndrome (IRIS). Among asymptomatic or oligosymptomatic individuals presenting late, where ART and primary prophylaxis are initiated, ∼10–20% will become symptomatic from drug toxicity or undiagnosed opportunistic complications, including IRIS, which require appropriate therapies. In this review we describe late presentation to HIV care, the scale of the problem, the evaluation of a late-presenting patient and challenges associated with initiation of potent anti-retroviral therapy (ART) in the setting of acute opportunistic infections and other comorbidities.

Immune reconstitution inflammatory syndrome (IRIS): review of common infectious manifestations and treatment options

The immune reconstitution inflammatory syndrome (IRIS) in HIV-infected patients initiating antiretroviral therapy (ART) results from restored immunity to specific infectious or non-infectious antigens. A paradoxical clinical worsening of a known condition or the appearance of a new condition after initiating therapy characterizes the syndrome. Potential mechanisms for the syndrome include a partial recovery of the immune system or exuberant host immunological responses to antigenic stimuli. The overall incidence of IRIS is unknown, but is dependent on the population studied and its underlying opportunistic infectious burden. The infectious pathogens most frequently implicated in the syndrome are mycobacteria, varicella zoster, herpesviruses, and cytomegalovirus (CMV). No single treatment option exists and depends on the underlying infectious agent and its clinical presentation. Prospective cohort studies addressing the optimal screening and treatment of opportunistic infections in patients eligible for ART are currently being conducted. These studies will provide evidence for the development of treatment guidelines in order to reduce the burden of IRIS. We review the available literature on the pathogenesis and epidemiology of IRIS, and present treatment options for the more common infectious manifestations of this diverse syndrome and for manifestations associated with a high morbidity.

Autoimmunity during lymphopenia: A two-hit model

The immune system has evolved elaborate mechanisms to respond to diverse antigens while minimizing the risk for autoimmune reactivity. During lymphopenia, however, some mechanisms that normally serve to maintain host tolerance are temporarily suspended. Peripheral T cells proliferate in response to self-antigens in lymphopenic hosts, but proliferation toward these same antigens is prevented when T cell numbers are normal. This process, termed homeostatic peripheral expansion, augments peripheral T cell number and limits repertoire skewing during recovery from lymphopenia and also predisposes lymphopenic hosts to autoimmune disease. This paper reviews murine and human settings in which autoimmunity occurs in the context of lymphopenia. We propose a two-hit model, in which lymphopenia plus another insult is sufficient to induce autoimmune disease. Among the secondary insults that appear sufficient to induce autoimmunity during lymphopenia are overproduction of IL-21 as occurs in the NOD.SCID mouse, depletion of Tregs as demonstrated in murine colitis and gastritis models, and tissue inflammation as seen in HIV infected patients who develop immune reconstitution inflammatory syndrome (IRIS). Delineating critical cofactors which result in autoimmune disease during lymphopenia can provide insight into the pathophysiology of naturally occurring autoimmune diseases as well as generating testable hypothesis for inducing tumor-specific autoimmunity in lymphopenic hosts with cancer.

Evidence base for using corticosteroids to treat HIV-associated immune reconstitution syndrome

Most of the evidence supporting the use of corticosteroids (steroids) for immune reconstitution syndrome (IRS) comes from case reports or retrospective series and is of low quality. However, when steroids are used, they have usually been associated with clinical improvement or resolution of IRS. Except in the case of hepatitis B- or C-associated IRS, there have been no reports of worsening of the IRS or adverse outcome due to steroid use. After ruling out other conditions which can mimic IRS, clinicians should strongly consider steroids when managing IRS associated with mycobacterial or fungal pathogens when there is severe disease, or when other measures have failed.

Incidence of immune reconstitution syndrome in HIV/tuberculosis-coinfected patients after initiation of generic antiretroviral therapy in India

This paper describes the incidence of immune reconstitution syndrome (IRS) from the developing world and implications for clinicians. Eleven of 144 HIV and tuberculosis (TB)-coinfected individuals followed for 72 person-years developed IRS within 6 months of initiating generic highly active antiretroviral therapy (HAART). All of the IRS patients were male, with a median age of 29 years; median CD4 at HAART initiation was 123 cells/mm3, and 6-month median CD4 rise was 124 cells/mm3. There was no statistical difference in CD4 rise or CD4 count and duration of TB treatment at HAART initiation between those who did and those who did not develop IRS (P = 0.8380). The median time to development of clinical IRS was 42 days (range 10-89 days). The incidence of IRS in this cohort is 15.2 cases per 100 patient-years. With increased coprevalence of opportunistic infections, especially TB, and increasing access to antiretroviral therapy in the developing world, clinicians in these countries must be able to identify IRS and relieve symptoms without compromising clinical care.

Recent advances in the diagnosis and management of tuberculosis

PURPOSE OF REVIEW

Tuberculosis (TB) remains one of the leading infectious killers of adults in the world today. This paper will review recent advances and understanding in the epidemiology, diagnosis, and management of TB.

RECENT FINDINGS

Tuberculosis remains a significant global threat, particularly in regions of the world heavily affected by HIV. Diagnosis of TB infection and disease rely on outdated and problematic methods, but newer immunologic and nucleic acid-based techniques are emerging. Treatment of latent TB infection still relies mainly on the use of isoniazid but several treatment-shortening strategies are being studied. Treatment of active disease has advanced little since the introduction of short-course chemotherapy with rifampin, but several new drugs are being developed and studied. Timely initiation of HIV treatment in co-infected patients is increasingly seen as important and strategies for initiating therapy for both diseases are being refined. The existence of immune reconstitution inflammatory reactions is also becoming more widely appreciated. Other populations at risk for TB such as those receiving TNF-alpha antagonists are being recognized and improved screening and control measures implemented.

SUMMARY

The global epidemiology of TB has been shaped in recent decades by HIV, urbanization and poverty. Diagnosis and treatment remain challenging, however, improved screening of at-risk populations and new diagnostic modalities and treatment strategies offer hope to the millions who suffer from tuberculosis.

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.

Clinical characteristics of IRIS syndrome in patients with HIV and tuberculosis

BACKGROUND

Some patients with HIV/tuberculosis (TB) coinfection who are on anti-TB treatment and highly active antiretroviral therapy (HAART) will develop an exacerbation of symptoms, signs or radiological manifestations of TB that are not due to relapse or recurrence of their TB. The aetiology of these immune reconstitution inflammatory syndrome (IRIS) reactions is unknown but it is presumed that they occur, at least in part, as a consequence of HAART-related reconstitution of immunity.

METHODS

Patients who were diagnosed with their first episode of definitive or presumed TB between January 2001 and July 2003 were identified from the Chelsea and Westminster TB/HIV database. The patients were classified into those who developed IRIS and those who did not using a set definition of the syndrome. Demographic, clinical and laboratory data relating to both HIV and TB were compared between the two groups.

RESULTS

A total of 55 cases of TB were identified, of which 45 cases were confirmed on culture or gene probe and 10 were presumed cases. Fourteen cases (25.5%) developed IRIS with a median (range) duration of 2.53 (0.53-14.97) months. The median baseline CD4 [interquartile range (IQR)] for the IRIS group was significantly lower at 80 (33-117) cells/mm3 (P = 0.05) than the non-IRIS group at 139 (77-284) cells/mm3. A significantly greater proportion of patients in the IRIS group [11/14 (78.60%), P = 0.011] had baseline CD4 < 100cells/mm3 compared with the non-IRIS group [16/41 (39.0%)]. There was no significant difference between the two groups when comparing the log10 baseline viral load (VL). Eight (57.0%) patients in the IRIS group had disseminated TB at baseline compared with seven (17.0%) in the non-IRIS group (P = 0.006). In those who had a detectable VL at baseline, the median fold change (IQR) in CD4 from baseline to 3 months was significantly higher in the IRIS group patients, 1.5 (0.6-5.6), compared with 0.7 (-0.2 to 1.0) for those in the non-IRIS group (P = 0.046).

CONCLUSIONS

Patients who develop IRIS are more likely to present with disseminated TB, have a CD4 count < 100 cells/mm3 and have a prompt rise in CD4 count in the initial 3 months of HAART.

Immune reconstitution disease associated with mycobacterial infections in HIV-infected individuals receiving antiretrovirals

Immune reconstitution disease (IRD) in HIV-infected patients is an adverse consequence of the restoration of pathogen-specific immune responses during the initial months of highly active antiretroviral treatment (HAART). Previously subclinical infections are "unmasked" or pre-existing opportunistic infections clinically deteriorate as host immunopathological inflammatory responses are "switched on". IRD is most frequently associated with mycobacterial infections. Our literature search identified 166 published cases of IRD associated with mycobacterial infections. We review the underlying immunological mechanisms, difficulties surrounding case definition and diagnosis, the wide diversity of clinical manifestations, and treatment. The importance of screening patients for mycobacterial disease before starting HAART and the critical impact of the timing of commencement of HAART in patients receiving treatment for tuberculosis are highlighted. We also discuss the problem of IRD associated with mycobacterial diseases in developing countries where tuberculosis prevalence is high and access to HAART is currently expanding.

[Treatment and prophylaxis of opportunistic infections in the course of HIV disease: a state of the art in 2004. Part 2: Viral, fungal and bacterial infections]

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 to 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.

Illness of Immune Reconstitution: Recognition and Management

Some individuals who initiate highly active antiretroviral therapy (HAART) develop new or worsening opportunistic infections or malignancies despite improvements in surrogate markers of HIV-1 infection. These events of paradoxical clinical worsening, also known as immune reconstitution syndromes (IRS), are increased in individuals with prior opportunistic infections or low CD4+ T-cell nadirs. They are thought to result from reconstitution of the immune system's ability to recognize pathogens or tumor antigens that were previously present, but clinically asymptomatic. There is no consensus regarding the diagnostic criteria or pathogenesis of IRS. Knowledge of their presentation and treatment is largely based on case reports. With the introduction of HAART into resource-limited settings, it is likely that significantly more and distinct forms of IRS will be observed. Prospective studies of the incidence and treatment of IRS in multiple settings are critical to better understand their pathogenesis and optimal management.

Immune restoration disease after antiretroviral therapy

Suppression of HIV replication by highly active antiretroviral therapy (HAART) often restores protective pathogen-specific immune responses, but in some patients the restored immune response is immunopathological and causes disease [immune restoration disease (IRD)]. Infections by mycobacteria, cryptococci, herpesviruses, hepatitis B and C virus, and JC virus are the most common pathogens associated with infectious IRD. Sarcoid IRD and autoimmune IRD occur less commonly. Infectious IRD presenting during the first 3 months of therapy appears to reflect an immune response against an active (often quiescent) infection by opportunistic pathogens whereas late IRD may result from an immune response against the antigens of non-viable pathogens. Data on the immunopathogenesis of IRD is limited but it suggests that immunopathogenic mechanisms are determined by the pathogen. For example, mycobacterial IRD is associated with delayed-type hypersensitivity responses to mycobacterial antigens whereas there is evidence of a CD8 T-cell response in herpesvirus IRD. Furthermore, the association of different cytokine gene polymorphisms with mycobacterial or herpesvirus IRD provides evidence of different pathogenic mechanisms as well as indicating a genetic susceptibility to IRD. Differentiation of IRD from an opportunistic infection is important because IRD indicates a successful, albeit undesirable, effect of HAART. It is also important to differentiate IRD from drug toxicity to avoid unnecessary cessation of HAART. The management of IRD often requires the use of anti-microbial and/or anti-inflammatory therapy. Investigation of strategies to prevent IRD is a priority, particularly in developing countries, and requires the development of risk assessment methods and diagnostic criteria.

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.

Acute Renal Failure on Immune Reconstitution in an HIV‐Positive Patient with Miliary Tuberculosis

Immune reconstitution syndrome following HAART in human immunodeficiency virus (HIV)-infected patients is characterized by inflammatory worsening of organ functions despite improvement in HIV surrogate markers of HIV infection. We describe a patient with miliary tuberculosis and urinary shedding of acid fast bacilli who developed acute renal failure 8 weeks after initiation of antituberculosis therapy and 6 weeks after initiation of HAART. The diagnostic workup and further course of disease implicated immune reconstitution syndrome as the cause of acute renal failure.

Immune Restoration in Patients with HIV Infection: HAART and Beyond

Since the introduction of highly active antiretroviral therapy (HAART), there has been a dramatic decrease in HIV-related morbidity and mortality. Suppressing HIV replication by HAART can result in a restoration of the CD4+ T-cell count and, consequently, a diminished risk of opportunistic infections. However, the degree of immune restoration that can be achieved with HAART varies from patient to patient. It is often incomplete and can be poorest in those patients who, because of their very low CD4+ counts, need it the most. Additional approaches are needed to increase immune restoration still further. Structured treatment interruptions, therapeutic immunization, and recombinant interleukin-2 are three such options that are currently being investigated.

Risk factors for development of paradoxical response during antituberculosis therapy in HIV-negative patients

The risk factors for development of paradoxical response were studied in a cohort of 104 patients with culture-documented Mycobacterium tuberculosis infection. Paradoxical deterioration occurred in 16 (15.4%) patients (case group) during antituberculosis therapy, involving lungs and pleura (n=4), spine and paraspinal tissue (n=5), intracranium (n=3), peritoneum (n=2), bone and joint (n=1), and lymph node (n=1). The median time from commencement of treatment to paradoxical deterioration was 56 days (range, 20-109 days). Compared with 53 patients without clinical deterioration after antituberculosis therapy (control group), patients with paradoxical response were more likely to have extrapulmonary involvement (62.5% vs. 17.0%; P<0.05) at initial diagnosis, to have lower baseline lymphocyte counts (672+/-315 cells/microl vs. 1,328+/-467 cells/microl; P<0.001), and to exhibit a greater surge in lymphocyte counts (627+/-465 cells/microl vs. 225+/-216 cells/microl; P<0.05) during paradoxical response. Further studies on lymphocyte subsets and cytokine levels would be useful in understanding the exact immunological mechanisms involved in immunorestitution.

Development of multiple abscesses in an HIV/TB co-infected patient after initiation of antituberculous and highly active antiretroviral therapy

Since the use of Highly Active Antiretroviral Therapy (HAART) for HIV infection, there have been increasing reports of systemic manifestations of immune restoration. This new clinical syndrome among HIV-infected patients is associated with underlying co-infections with mycobacteria, cytomegalovirus, hepatitis B and C infections, etc.... We report on an HIV/tuberculosis (TB) co-infected patient who developed an immune restoration inflammatory syndrome after initiation of HAART and anti-TB treatment. She developed fever, large abscesses and pleural and peritoneal effusions. Systemic symptoms decreased during corticosteroid treatment, but abscesses only disappeared 8 months after the start of the anti-TB treatment.

Case report. Recurrence of increased intracranial pressure with antiretroviral therapy in an AIDS patient with cryptococcal meningitis

We present the case of an AIDS patient with cryptococcal meningitis who, after an excellent clinical and mycological response to antifungal therapy, developed an exacerbation of signs and symptoms, including elevated intracranial pressure and an increase in cerebrospinal fluid cryptococcal antigen and white blood cells, following the initiation of highly active antiretroviral therapy (HAART). Cultures yielded no growth and the patient responded to repeated lumbar punctures without changing or intensifying antifungal therapy. To our knowledge, this is the first report of symptomatic elevated intracranial pressure occurring during HAART-related immune recovery in a patient with cryptococcal meningitis. Exacerbation of symptoms does not necessarily reflect mycological failure that requires a change in antifungal therapy, but may relate to acutely increased intracranial pressure that will respond to simple measures, such as repeated lumbar punctures.

Human immunodeficiency virus pathogenesis: insights from studies of lymphoid cells and tissues

Although plasma virus load is invaluable for monitoring human immunodeficiency virus (HIV) infection, key pathogenesis events and most viral replication take place in lymphoid tissues. Decreases in virus load associated with therapy occur in plasma and tissues, but persistent latent infection and ongoing viral replication are evident. Many unanswered questions remain regarding mechanisms of HIV-associated lymphocyte depletion, but partial CD4(+) cell reconstitution after therapy likely reflects retrafficking from inflamed tissues, increased thymic or peripheral production, and decreased destruction. Rapid establishment of latent infection and the follicular dendritic cell-associated viral pool within lymphoid tissues suggest that only early intervention could substantially alter the natural history of HIV. If therapy is started prior to seroconversion, some individuals retain potent HIV-specific cellular immune responsiveness that is suggestive of delayed progression. Although complete virus eradication appears out of reach at present, more attention is being directed toward the prospect of boosting HIV-specific immune responses to effect another type of "clinical cure": immune-mediated virus suppression in the absence of therapy.

Acute respiratory failure following HAART introduction in patients treated for Pneumocystis carinii pneumonia

Cases of paradoxical worsening of opportunistic infections shortly after the beginning of highly active antiretroviral therapy (HAART) prompted questions on the optimal timing of introduction of HAART in patients with inaugural AIDS-related opportunistic infections. We describe three cases of acute respiratory failure after early introduction of HAART in patients treated for Pneumocystis carinii pneumonia (PCP). The three patients had severe PCP that initially improved with anti-PCP and adjunctive steroid therapy. HAART was introduced 1 to 16 d after diagnosis of PCP, and steroids were stopped on Day 15. Seven to 17 d after HAART introduction, the three patients developed a second episode of severe acute respiratory failure with high-grade fever and patchy alveolar opacities on the chest roentgenogram. PCP resistant to cotrimoxazole, pulmonary superinfection, and drug-related pneumonitis were suspected but subsequently ruled out. Bronchoalveolar lavage and lung pathologic findings showed severe nonspecific pulmonary inflammatory foci surrounding a few persistent P. carinii cysts. All three patients recovered after HAART interruption or steroid reintroduction. We conclude that acute respiratory failure can recur after initiation of antiretroviral therapy in patients being treated for severe PCP. This phenomenon could result from rapid pulmonary recruitment of fully competent immune and inflammatory cells responding to a few persistent P. carinii cysts. A short course of steroid therapy may suppress this reaction.

Paradoxical worsening of tuberculosis in HIV-infected persons

OBJECTIVE

To determine the incidence of paradoxical worsening of tuberculosis (TB) in HIV-infected persons.

DESIGN

Observational cohort study.

SETTING

Public, urban TB clinic.

PATIENTS

HIV-infected persons treated for TB between January 1, 1996, and December 31, 1999, and followed through June 30, 2000.

INTERVENTION

Patients received standard anti-TB therapy. Antiretroviral therapy was provided by primary medical providers. Patients receiving antiretroviral therapy were given nucleoside reverse transcriptase inhibitors alone or highly active antiretroviral therapy (HAART; nucleoside reverse transcriptase inhibitors in combination with a protease inhibitor or a nonnucleoside reverse transcriptase inhibitor).

MAIN OUTCOME MEASURE

Paradoxical worsening of TB.

RESULTS

There were 82 TB cases in 76 patients. Paradoxical worsening was identified in 6 of 82 cases (7%; 95% confidence interval, 3 to 15%). Paradoxical worsening occurred in 3 of 28 cases (11%) in patients receiving HAART and in 3 of 44 cases (7%) in patients not receiving antiretroviral therapy (p = 0.67). Cases complicated by paradoxical worsening were more likely to have both pulmonary and extrapulmonary disease at initial diagnosis than cases without paradoxical worsening (83% vs 24%; p = 0.006). TB relapse occurred in 2 of 6 cases (33%) in patients with paradoxical worsening and in 4 of 76 cases (5%) in patients without paradoxical worsening (p = 0.06).

CONCLUSIONS

Paradoxical worsening of TB occurred less frequently than in previous reports and was not associated with HAART. Paradoxical worsening also appeared to be associated with an increased risk of TB relapse. Further studies are warranted to better characterize the risk factors for paradoxical worsening and the appropriate duration of anti-TB therapy in patients in whom it occurs.

[Opportunistic episodes in patients infected with the human immunodeficiency virus during the first 6 months of HAART]

BACKGROUND

We aimed at analysing the incidence and characteristics of opportunistic events (OE) within a few months after starting highly active antiretroviral therapy (HAART) in HIV infected patients.

PATIENTS AND METHOD

Retrospective study of HIV infected outclinic patients attended in a HIV/AIDS reference hospital in Madrid, who initiated HAART during the second semester of 1998, with a baseline CD4 cell count 250 x 10(6) cells/l. We recorded the incidence of OE within 6 months after beginning HAART and analysed virological and immunological parameters, sociodemographic variables and types of antiretroviral treatment.

RESULTS

The study included 269 patients. Twenty-one (7.8%) OE were recorded. At the onset of HAART, the mean CD4 cell count in these 21 patients was 137 (92) x 10(6)/land the median viral load was 24,043 cop/ml. At the time of OE diagnosis, these parameters were 218 (114) x 10(6)/l (p = 0.012) and < 500 cop/ml, respectively. OE were distributed as follows: herpes zoster, 9 cases (43%), Pneumocystis carinii pneumonia, 5 cases (24%), Kaposi sarcoma,3 cases (14%) and tuberculosis, cerebral toxoplasmosis, cytomegalovirus retinitis, and non-Hodgkin lymphoma, 1 case each. Overall, 78% of OE occurred within first 4 months after beginning HAART. In addition, an OE was developed by 8% patients treated with NRTI and PI, 2% treated with NRTI and NNRTI, and 10% treated with NRTI,NNRTI and PI (p = 0.44).

CONCLUSIONS

HIV-infected subjects with low CD4 counts are prone to develop OE within the first few moths after beginning HAART. An inflammatory response to latent antigens due to the immune recovery might explain this fact.

Immunorestitution disease involving the innate and adaptive response

Immunorestitution disease (IRD) is defined as an acute symptomatic or paradoxical deterioration of a (presumably) preexisting infection that is temporally related to the recovery of the immune system. We report the temporal sequence of events that led to IRD caused by Pneumocystis carinii and Aspergillus terreus in 2 human immunodeficiency virus (HIV)-negative patients soon after the recovery of adaptive and innate immunity, respectively, and we review episodes noted in the English-language literature that fit the definition of IRD (109 episodes in 107 patients). The median time from the recovery of neutrophil counts or termination of steroid therapy to the development of IRD was 8 days in cases of pulmonary aspergillosis (23 episodes) and hepatosplenic candidiasis (8) and 21 days for viral diseases such as hepatitis B (24) and viral pneumonitis (6). For IRD due to mycobacteriosis (27 episodes) and cryptococcosis (4) in HIV-positive patients, the median interval between the initiation of highly active antiretroviral therapy (HAART) and the onset of IRD was 11 days; for viral infections, including those due to cytomegalovirus (14), hepatitis B virus (1), and hepatitis C virus (2), the median interval was 42 days. As an emerging clinical entity, IRD merits further study to optimize treatment of immunosuppressed patients.