Immune reconstitution disease associated with parasitic infections following initiation of antiretroviral therapy

Female Genital Schistosomiasis and HIV: Research Urgently Needed to Improve Understanding of the Health Impacts of This Important Coinfection

Evidence suggests that there are important interactions between HIV and female genital schistosomiasis (FGS) that may have significant effects on individual and population health. However, the exact way they interact and the health impacts of the interactions are not well understood. In this article, we discuss what is known about the interactions between FGS and HIV, and the potential impact of the interactions. This includes the likelihood that FGS is an important health problem for HIV-positive women in Schistosoma-endemic areas potentially associated with an increased risk of mortality, cancer, and infertility. In addition, it may be significantly impacting the HIV epidemic in sub-Saharan Africa by making young women more susceptible to HIV. We call for immediate action and argue that research is urgently required to address these knowledge gaps and propose a research agenda to achieve this.

Neurological disorders in HIV in Africa: a review

BACKGROUND

Neurological disorders in HIV infection are a common cause of morbidity and mortality. The aim of this paper is to provide a narrative overview of up to date information concerning neurological disorders affecting HIV infected persons in Africa.

METHODS

Seminal research concerning neurological disorders among HIV-infected adults in sub-Saharan Africa from prior to 2000 was combined with an in-depth search of PubMed to identify literature published from 2000 to 2017. The following Mesh terms were used. "Nervous System Diseases" "HIV Infections" and "Africa South of the Sahara" and "Seizures" or "Spinal Cord Diseases" or "Peripheral Nervous System Diseases" or "AIDS Dementia Complex" or "Opportunistic Infections" or "Immune Reconstitution Inflammatory Syndrome" or "Stroke". Only those articles written in English were used. A total of 352 articles were identified, selected and reviewed and 180 were included in the study. These included case series, observational studies, interventional studies, guidelines and reviews with metanalyses. The author also included 15 publications on the subject covering the earlier phase of the HIV epidemic in Africa from 1987 to 1999 making a total of 195 references in the study. This was combined with extensive personal experience diagnosing and treating these neurological disorders.

RESULTS

Neurological disorders were common, typically occurring in WHO stages III/IV. These were in three main categories: those arising from opportunistic processes mostly infections, direct HIV infection and autoimmunity. The most common were those arising from direct HIV infection occurring in >50%. These included HIV-associated neurocognitive dysfunction (HAND), neuropathy and myelopathy. Opportunistic infections occurred in >20% and frequently had a 6-9-month mortality rate of 60-70%. The main causes were cryptococcus, tuberculosis, toxoplasmosis and acute bacterial meningitis. Concurrent systemic tuberculosis occurred in almost 50%.

CONCLUSION

Neurological disorders are common in HIV in Africa and the main CNS opportunistic infections result in high mortality rates. Strategies aimed at reducing their high burden, morbidity and mortality include early HIV diagnosis and anti-retroviral therapy (ART), screening and chemoprophylaxis of main opportunistic infections, improved clinical diagnosis and management and programme strengthening.

Immune Reconstitution Inflammatory Syndrome in HIV-Infected Immigrants

Immune reconstitution inflammatory syndrome (IRIS) includes a group of potentially serious inflammatory processes that may be present in HIV-infected patients after initiating highly active antiretroviral therapy (HAART). Paradoxical IRIS is a worsening of symptoms, after an overwhelming response to a previously diagnosed opportunistic infection (OI); unmasking IRIS reveals a previously occult OI. The main objective of the study was to describe the epidemiological, clinical, and outcome data of HIV-infected immigrants, stratified according to high- or low-income countries of origin, who developed IRIS and to compare them with native-born Spanish patients. This retrospective study reviewed all patients with HIV infection admitted to the Unit of Infectious Diseases and Tropical Medicine between 1998 and 2014. IRIS was identified in 25/138 (18%) immigrant patients and 24/473 (5%) native-born Spanish patients infected with HIV. Most cases, 19/25 (76%), were of unmasking IRIS. The time elapsed between initiation of HAART and development of IRIS was significantly longer in patients with unmasking versus paradoxical IRIS. OIs, in particular due to mycobacteria, were the most frequently involved processes. Twenty percent of patients died. The comparison of immigrant and native-born patients found significant differences for both IRIS type (higher incidence of paradoxical forms among immigrants) and for the absence of malignancies in native-born patients. No significant differences were found when the data of immigrants from low- and high-income countries were compared.

Diagnosis and Treatment of Leishmaniasis: Clinical Practice Guidelines by the Infectious Diseases Society of America (IDSA) and the American Society of Tropical Medicine and Hygiene (ASTMH)

It is important to realize that leishmaniasis guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. The IDSA and ASTMH consider adherence to these guidelines to be voluntary, with the ultimate determinations regarding their application to be made by the physician in the light of each patient's individual circumstances.

Development of visceral leishmaniasis in an HIV(+) patient upon immune reconstitution following the initiation of antiretroviral therapy

CASE PRESENTATION

Here, we report on a case of VL in an HIV-infected patient from the Republic of Georgia who had moved to Germany 14 years before and who had travelled several times to southern Europe in between. After presenting with typical Pneumocystis jiroveci pneumonia, which was treated appropriately, the patient was started on antiretroviral therapy. Shortly thereafter, however, he developed fever of unknown origin. All laboratory assays for the diagnosis of various infectious agents including serological assays and polymerase chain reaction testing of bone marrow aspirate to diagnose VL did not yield positive results at first. Only upon repetition of these tests, diagnosis of VL could be made and the patient treated accordingly.

CASE DISCUSSION

Visceral leishmaniasis (VL) is a common opportunistic infection in HIV-positive patients from endemic countries but occurs rarely following antiretroviral treatment. This case demonstrates that patients who develop VL upon immune reconstitution may not be diagnosed initially by standard laboratory assays for the diagnosis of VL and underlines the necessity to repeat serologic and molecular biologic testing for VL in cases of fever of unknown origin in patients from or with travel history to endemic countries.

Immune reconstitution inflammatory syndrome in HIV-infected patients

Access to antiretroviral therapy (ART) is improving worldwide. Immune reconstitution inflammatory syndrome (IRIS) is a common complication of ART initiation. In this review, we provide an overview of clinical and epidemiological features of HIV-associated IRIS, current understanding of pathophysiological mechanisms, available therapy, and preventive strategies. The spectrum of HIV-associated IRIS is described, with a particular focus on three important pathogen-associated forms: tuberculosis-associated IRIS, cryptococcal IRIS, and Kaposi's sarcoma IRIS. While the clinical features and epidemiology are well described, there are major gaps in our understanding of pathophysiology and as a result therapeutic and preventative strategies are suboptimal. Timing of ART initiation is critical to reduce IRIS-associated morbidity. Improved understanding of the pathophysiology of IRIS will hopefully enable improved diagnostic modalities and better targeted treatments to be developed.

Co-infection of HIV and tropical infectious agents that affect the nervous system

Tropical infections refer to a group of diseases usually located in regions with a warm climate, particularly affecting developing countries, partly because of the conditions that allow them to thrive. However, due to the increased international travel, infectious agents that were previously limited to tropical regions pose an increasing threat to populations at risk for opportunistic infection (OI), especially those infected with the HIV. Tropical infections can facilitate HIV transmission and accelerate the progression of asymptomatic HIV infection to AIDS. Some have the potential to alter the epidemiology, natural history, and/or response to treatment of the other. The introduction of highly active antiretroviral therapy has provided a huge benefit for the vast majority of patients infected with the HIV, by allowing the immune system to recover, improving the clinical and radiological results and reducing the number of OI. On the other hand, some patients have developed various disorders of immune reconstitution, resulting in either hyper-immune inflammatory response to an exogenous antigen or autoimmunity. A significant proportion of these cases have been reported in immigrants from tropical countries to high-income countries, therefore awareness of these phenomena is needed since clinical presentations are often atypical and pose diagnostic challenges. This article reviews some of the key diagnostic aspects of tropical infections associated with HIV infection.

Prevalence of Strongyloides stercoralis infection among HIV-positive immigrants attending two Italian hospitals, from 2000 to 2009

In patients with Strongyloides stercoralis infection, a dysregulation of host immunity can lead to hyperinfection syndrome (HS) and disseminated strongyloidiasis (DS), characterized by high fatality rate. HS has been reported in HIV-positive patients following use of corticosteroids or during immune reconstitution inflammatory syndrome (IRIS). A retrospective study was conducted to estimate the prevalence of S. stercoralis infection among HIV-positive immigrants, attending two Italian hospitals. From January 2000 to August 2009, 138 HIV-positive immigrants were systematically screened for strongyloidiasis, as a part of their routine care, with an indirect immunofluorescent antibody test (IFAT) developed at the Centre for Tropical Diseases, Sacro Cuore Hospital of Negrar, Verona. The majority were also submitted to stool examination. Fifteen (11%) resulted infected by S. stercoralis, of whom four (27%) had a negative serology (diagnosis made with stool examination). A higher eosinophil count (0·94 versus 0·24×10(9)/l, P<0·01) and more frequent gastrointestinal and cutaneous symptoms (odds ratio: 4·8 and 5·8, respectively) were found in patients with strongyloidiasis compared with controls. The IFAT is more sensitive than direct parasitological methods. The proportion of false negative results was higher than expected based on the theoretical test sensitivity. Considering the high prevalence detected and the apparent, lower sensitivity of serology, we propose a systematic screening for Strongyloides infection, with both serology and stool culture, for all HIV-positive immigrants coming from endemic areas.

A morphological approach to the diagnosis of protozoal infections of the central nervous system

Protozoal infections, though endemic to certain regions, can be seen all around the world, because of the increase in travel and migration. In addition, immunosuppression associated with various conditions, particularly with HIV infection, favors the occurrence of more severe manifestations and failure to respond to treatments. The CNS may be the only affected system; when not, it is often the most severely affected. Despite information obtained from clinical, laboratory, and imaging procedures that help to narrow the differential diagnosis of intracranial infections, there are cases that need confirmation with biopsy or autopsy. Predominant presentations are meningoencephalitis (trypanosomiasis), encephalopathy (cerebral malaria), or as single or multiple pseudotumoral enhancing lesions (toxoplasmosis, reactivated Chagas' disease). The immune reconstitution disease, resulting from enhancement of pathogen-specific immune responses after HAART, has altered the typical presentation of toxoplasmosis and microsporidiosis. In this paper, a morphological approach for the diagnosis of protozoal infections affecting the CNS (amoebiasis, cerebral malaria, toxoplasmosis, trypanosomiasis, and microsporidiosis) is presented.

Fetal death as a result of placental immune reconstitution inflammatory syndrome

A 26-year-old woman was HIV-1 diagnosed at 11 weeks of pregnancy (CD4 = 7/mm(3), HIV-1 RNA = 108,000 copies/mL) with immunity against toxoplasmosis (Toxoplasma IgG = 1800 UI/mL). A fetal death was diagnosed 7 weeks after starting HAART (CD4 = 185/mm(3), HIV-1 RNA = 391 copies/mL) with a positive Toxoplasma PCR on fetal tissues and amniotic fluid. The absence of severe toxoplasmic foetopathy, the very exaggerated and atypical placental inflammation and the immune restoration context led to the diagnosis of placental IRIS associated with Toxoplasma gondii reactivation. This outcome remains undescribed and could represent an issue in resource-limited settings where HIV-pregnant patients are often severely immunodeficient and infected with opportunistic pathogens.

Immunopathogenesis of immune reconstitution disease in HIV patients responding to antiretroviral therapy

PURPOSE OF REVIEW

The aim of this article is to review the most recent literature regarding the immunopathogenesis of pathogen-associated immune reconstitution disease and to discuss the role of immune activation and various effector molecules and cells such as macrophages, effector and regulatory T cells, and natural killer cells in immune reconstitution disease.

RECENT FINDINGS

Many HIV patients receiving antiretroviral treatment develop immune reconstitution disease, which is characterized by exaggerated inflammatory immune responses to replicating or dead pathogens. In the majority of these cases, immune reconstitution disease is associated with restoration of pathogen-specific cellular immune responses involving CD4 or CD8 effector T cells. The precise conditions that trigger immune reconstitution disease have not yet been identified. Immune reconstitution disease patients have overt immune activation, which may be due to poor homeostatic control after the fast initial immune recovery in patients receiving antiretroviral therapy. Poor homeostatic control in immune reconstitution disease patients may be linked to unbalanced restoration of effector and regulatory T cells.

SUMMARY

Although the precise mechanism of immune reconstitution disease is not well understood, it is probably related to rapid restoration of pathogen-specific immune responses and poor homeostatic control that promote exaggerated immunopathological responses, especially if viable pathogens or pathogen debris are present at high concentrations.

Frequent hemorrhagic lesions in cerebral toxoplasmosis in AIDS patients

Cerebral toxoplasmosis is a frequent complication in immunosuppressed patients such as AIDS (acquired immunodeficiency syndrome). Frequently, lesions are located deep in the brain which are inaccessible for biopsy making rapid diagnosis dependent on accurate interpretation of neuroimaging findings. The commonest cranial CT findings reported in toxoplasmosis are ring enhancing hypodense lesions in basal ganglia or cortical gray matter. Hemorrhage has only rarely been described and is usually seen following antitoxoplasma treatment. We reviewed the records of 11 AIDS patients with cerebral toxoplasmosis and found multiple hemorrhagic cerebral, cerebellar, or brain stem lesions in 7 of 11 patients. Six patients had hemorrhage at the time of initial clinical presentation and one developed hemorrhage following 2 weeks of antitoxoplasma treatment. We conclude that hemorrhagic lesions are frequently found on cranial MRI scans in cerebral toxoplasmosis. AIDS patients presenting with hemorrhagic cerebral lesions should be considered for a trial of presumptive antitoxoplasma treatment.

Immunogenetics of drug-induced skin blistering disorders. Part I: Perspective

The overall immunopathogenesis relevant to a large series of disorders caused by a drug or its associated hyperimmune condition is discussed based upon the examination of the genetics of severe drug-induced bullous skin problems (sporadic idiosyncratic adverse events, including Stevens-Johnson syndrome and toxic epidermal necrolysis). An overarching pharmacogenetic schema is proposed. Immune cognition and early-effector processes are focused upon and a challenging synthesis around systems evolution is explained by a variety of projective analogies. Etiology, human leukocyte antigen-B, immune stability, dysregulation, pharmacomimicry, viruses and an aggressive ethnically differentiated 'karmic' response are discussed.

[Human immunodeficiency virus and AIDS-associated immune reconstitution syndrome. State of the art]

Since the arrival of highly active antiretroviral therapy (HAART), immune reconstitution syndrome (IRS) has become an increasingly more frequent complication in patients with human immunodeficiency virus (HIV) infection. This article presents a review of the available evidence on this subject, indexed in MEDLINE-PUBMED, BVS-BIREME, and BioMed Central. The review covers the definition, epidemiology, classification, and diagnostic criteria related to IRS. In addition, the clinical particularities of the most frequent etiologies are described, and a proposal for a therapeutic approach is formulated. The prognosis and future implications of this syndrome in the epidemiology of some infectious illnesses in the HIV-positive population are included. Several unresolved aspects are mentioned, such as those related to the pathophysiology of the condition, use of biomarkers for the diagnosis, and the need for evidence-based therapeutic algorithms to enable standardization of treatment for these patients.

[Treatment of opportunistic infections in adolescent and adult patients infected with the human immunodeficiency virus during the era of highly active antiretroviral therapy. AIDS Study Group (GESIDA) and National AIDS Plan Expert Committee]

Despite the huge advance that highly active antiretroviral therapy has represented for the prognosis of infection by human immunodeficiency virus (HIV), opportunistic infections continue to be a cause of morbidity and mortality in HIV-infected patients. This is often the case because of severe immunodepression, poor adherence to antiretroviral therapy, failure of therapy, or the fact that patients are unaware of their HIV-positive status and debut with an opportunistic infection. This article updates the guidelines on treatment of acute episodes of various opportunistic infections in HIV-infected patients, including infections due to parasites, fungi, viruses, mycobacteria, and bacteria. This edition has a new chapter on imported parasite infections as well as additional information on endemic mycoses in the chapter on fungal infections, taking into account the growing number of immigrants in our setting. Lastly, the chapter on the immune reconstitution syndrome has also been updated, providing relevant data on a phenomenon that has clinical and diagnostic repercussions in patients who start antiretroviral therapy while they are severely immunodepressed (English version available at http://www.gesida.seimc.org).

Treatment of parasitic diarrhea in HIV-infected patients

Parasitic infections responsible for diarrhea have a worldwide distribution, overlapping with AIDS in most countries. Indeed, highly active antiretroviral therapy has markedly reduced the incidence of most parasitic opportunistic infections, but parasite-related diarrhea remains frequent and probably underestimated in developing countries. In this review, we focus on the advances in molecular epidemiology, diagnosis and current treatment of the most prevalent parasitic infections in HIV-infected patients. Most of these parasites are protozoa, whose diagnosis at the laboratory requires some adapted technique and expertise. We highlight the importance of diagnosis and the skill of the laboratory of parasitology, since most parasitic infections responsible for diarrhea in AIDS patients can be treated.