Certain HLA-DR5 and -DR6 major histocompatibility complex class II alleles are associated with a CD8 lymphocytic host response to human immunodeficiency virus type 1 characterized by low lymphocyte viral strain heterogeneity and slow disease progression

Clonal T-cell Large Granular Lymphocytic Disorders Manifesting in Patients with HIV-1 Infection: Case Series and Review of the Literature

We report five patients with human immunodeficiency virus-1/acquired immunodeficiency syndrome (HIV-1/AIDS) who developed T-cell large granular lymphocytic proliferation (T-LGLP) or leukemia (T-LGLL). None of the patients fulfilled criteria for diagnosis of diffuse infiltrative lymphocyte syndrome (DILS) or HIV-associated CD8+ lymphocytosis syndrome at the time of diagnosis of LGL. The immunophenotype of malignant T-cells was identical in three patients with co-expression of CD3, CD8, CD57, and T-cell receptor (TCR) alpha/beta. Three out of five patients were also diagnosed with clonal disorders of B-cell origin including diffuse large B-cell lymphoma, Burkitt’s lymphoma, and monoclonal gammopathy of undetermined significance (MGUS). Two patients developed cytopenias due to T-LGLL prompting initiation of therapy. Our study suggests that chronic viral infection with HIV can contribute to the evolution of T-LGLP. Clinical and laboratory characteristics of T-LGLP associated with HIV-1/AIDS resemble those of immunocompetent patients.

HIV related pulmonary arterial hypertension: epidemiology in Africa, physiopathology, and role of antiretroviral treatment

The development of HIV related pulmonary arterial hypertension (PAH) reduces the probability of survival by half as compared with HIV-infected individuals without HIV related PAH. HIV infected patients have a greater incidence of PAH compared to general population and have a 2500-fold increased risk of developing PAH. It is therefore important to have a recent overview of the problem in Africa, the most HIV affected part of the world (70 % of all HIV infection in the world). First, we discussed the epidemiology of HIV-related PAH in Africa. Second, the current understanding of the HIV-related PAH pathogenesis has been covered. Third, role of highly active antiretroviral therapy on HIV-related PAH has been revisited. There are few data concerning epidemiology of HIV related pulmonary hypertension in Africa leading to necessity to conduct further prospective large studies. The prevalence of PAH among HIV infected people in Africa varies from 5 to 13 %. The prevalence of HIV-related PAH in Africa is notably high compared to those in developed countries and in general population. The pathogenesis of PAH is clearly complex, and probably results from the interaction of multiple modulating genes with environmental factors. The physiopathology includes cytokines secretion increase which induces dysregulation of endothelial and vascular smooth muscle cell growth and imbalance of endogenous vasodilators and constrictors; HIV viral proteins which induces vascular oxidative stress, smooth myocyte proliferation and migration, and endothelial injury and genetic predisposition due to some major histocompatibility complex alleles, particularly HDL-DR6 and HLA-DR5. Histologically, HIV related PAH has the same characteristics with other types PAH. Antiretroviral therapy have a beneficial effect on the outcome of HIV related pulmonary hypertension, but it lacks evidence from large prospective studies.

Manifestations of HIV infection in the peripheral nervous system

Peripheral nerve disorders are associated with all stages of HIV infection. Distal sensory polyneuropathy is characterised by often-disabling pain that is difficult to treat. It is prevalent in both high-income and low-income settings. In low-income settings, use of potentially neurotoxic antiretrovirals, which are inexpensive and widely available, contributes substantially to incidence. Research has focused on identification of factors that predict risk of distal sensory polyneuropathy and elucidation of the multifactorial mechanisms behind pathogenesis. Sensorimotor polyneuropathies and polyradiculopathies are less frequent than distal sensory polyneuropathy, but still occur in low-income settings and have potentially devastating consequences. However, many of these diseases can be treated successfully with a combination of antiretroviral and immune-modulating therapies. To distinguish between peripheral nerve disorders that have diverse, overlapping, and frequently atypical presentations can be challenging; a framework based on a clinicoanatomical approach might assist in the diagnosis and management of such disorders.

Polyneuropathy associated with the diffuse infiltrative lymphocytosis syndrome

Diffuse infiltrative lymphocytosis syndrome (DILS) arises in HIV-positive patients secondary to infiltration of lymphocytes into the peripheral tissues and produces the disease's characteristic symptoms-parotid gland enlargement and a sicca syndrome. Many patients, however, first seek medical attention for treatment of the extraglandular manifestations of DILS, most commonly interstitial pneumonitis. In this case report, we describe an atypical presentation of DILS characterized by polyradiculoneuropathy in the absence of parotid gland enlargement or interstitial pneumonitis. Minor salivary gland biopsy of the patient's lip confirmed a chronic inflammatory state with lymphoid aggregates within the minor salivary glands. He was started on prednisone with immediate improvement in his symptoms. This report illustrates for clinicians the diverse extraglandular manifestations of DILS and underscores the importance of considering it in the differential diagnosis of HIV-positive patients with a preserved CD4 count who present with peripheral neuropathy.

Cystic lymphoid hyperplasia of the parotid gland in HIV-positive and HIV-negative patients: quantitative immunopathology

BACKGROUND

Benign lymphoepithelial lesions of the parotid include a spectrum of disorders ranging from lymphoepithelial sialadenitis (LESA) of Sjögren syndrome to lymphoepithelial cysts (LEC) and both human immunodeficiency virus (HIV)-related and -unrelated cystic lymphoid hyperplasia (CLH). They share a common microscopic appearance characterized by epimyoepithelial islands and/or epithelial lined cysts in a lymphoid stroma. However, they differ greatly regarding their etiology, clinical presentation, and management.

OBJECTIVE

The purpose of this study was to establish specific immunophenotypic profiles for these diverse disease entities.

STUDY DESIGN

Four cases of HIV+ CLH, 5 cases of HIV- CLH, 3 cases of LESA of Sjögren syndrome, and 3 cases of sporadic LEC were quantitatively analyzed for distribution of lymphoreticular cell subpopulations, using antibodies against CD20, CD45RO, CD4, CD8, CD57, and CD68.

RESULTS

The cystic lesions in both the HIV+ and HIV- cases were microscopically analogous. However, a marked decrease in the interfollicular CD4:CD8 ratio was observed in all HIV+ CLH cases, which was statistically significant when compared with the HIV- cases (P = .02) and cases of LESA of Sjögren syndrome (P = .03). No significant differences regarding the distribution of CD20+ B lymphocytes in epithelial cyst lining or the interfollicular or follicular distribution of CD20+, CD45RO+, CD57+, and CD68+ cells were present among the different groups.

CONCLUSION

Analysis of the interfollicular CD4:CD8 ratio may offer a simple immunophenotypic approach in the distinction of HIV+ from other lymphoepithelial lesions of the parotid gland, when HIV status is unknown and p24 immunohistochemistry is not readily available.

HIV infection and rheumatic diseases: the changing spectrum of clinical enigma

In this article, the authors discuss the occurrence and prevalence of rheumatic syndromes before and after highly active antiretroviral therapy became the usual mode of treatment. The immunologic, environmental, and genetic factors behind the combination of HIV infection and rheumatic manifestation contribute to the complexity of these diseases. Miscellaneous case reports are discussed in relation to HIV infection. The authors conclude that geriatric care of HIV patients is on the horizon as more people have access to newer, more effective therapy and mortality is on the decline. Younger HIV patients will be committed to a lifetime of therapy to address bone disease and other chronic problems. In the future, newer agents may steer the clinical scenario in unforeseen directions.

Human leukocyte antigen polymorphisms in Italian primary biliary cirrhosis: a multicenter study of 664 patients and 1992 healthy controls

Genetic factors are critical in determining susceptibility to primary biliary cirrhosis (PBC), but there has not been a clear association with human leukocyte antigen (HLA) genes. We performed a multicenter case-control study and analyzed HLA class II DRB1 associations using a large cohort of 664 well-defined cases of PBC and 1992 controls of Italian ancestry. Importantly, healthy controls were rigorously matched not only by age and sex, but also for the geographical origin of the proband four grandparents (Northern, Central, and Southern Italy). After correction for multiple testing, DRB1*08 [odds ratio (OR), 3.3; 95% confidence interval (CI), 2.4-4.5] and DRB1*02 (OR 0.9; 95% CI 0.8-1.2) were significantly associated with PBC, whereas alleles DRB1*11 (OR 0.4; 95% CI 0.3-0.4) and DRB1*13 (OR 0.7; 95% CI 0.6-0.9) were protective. When subjects were stratified according to their grandparental geographical origin, only the associations with DRB1*08 and DRB1*11 were common to all three areas. Associated DRB1 alleles were found only in a minority of patients, whereas an additive genetic model is supported by the gene dosage effect for DRB1*11 allele and the interaction of DRB1*11,*13, and *08. Lastly, no significant associations were detected between specific DRB1 alleles and relevant clinical features represented by the presence of cirrhosis or serum autoantibodies. In conclusion, we confirm the role for HLA to determine PBC susceptibility and suggest that the effect of HLA is limited to patient subgroups. We suggest that a large whole-genome approach is required to identify further genetic elements contributing to the loss of tolerance in this disease.

A case of acute renal failure associated with diffuse infiltrative lymphocytosis syndrome

BACKGROUND

A 58-year-old African American man with an uncontrolled HIV infection presented to hospital with nephrotic syndrome and diffuse lymphadenopathy. The patient had been taking highly active antiretroviral therapy (HAART; lamivudine, abacavir, fosamprenavir and ritonavir) for 10 years. A renal biopsy showed acute granulomatous interstitial nephritis. Despite a negative tuberculin skin test, he was treated with antituberculosis drugs for 12 months without improvement of his renal profile. Two months after antituberculosis treatment was discontinued, the patient was readmitted to hospital because of acute renal failure. Corticosteroid therapy (prednisone) was started and resulted in a marked improvement in renal function. However, 18 months after steroids were discontinued, renal function declined dramatically. Furthermore, the patient had CD8+ lymphocytosis as well as interstitial tissue infiltration by CD8+ T lymphocytes.

INVESTIGATIONS

Physical examination, plasma HIV viral load, lymphocyte counts, urinalysis, tuberculin skin test, liver function tests, renal ultrasonography, human leukocyte antigen (HLA) typing, renal and minor salivary gland biopsies, ophthalmological examination, chest radiography and culture of bronchoalveolar lavage fluid.

DIAGNOSIS

Acute granulomatous interstitial nephritis secondary to diffuse infiltrative lymphocytosis syndrome.

MANAGEMENT

HAART and prednisone.

Changing spectrum of the diffuse infiltrative lymphocytosis syndrome

OBJECTIVE

To describe the changing clinical spectrum of patients with diffuse infiltrative lymphocytosis syndrome (DILS) after the introduction of highly active antiretroviral treatment (HAART), and to carry out HLA class II oligotyping in these patients.

METHODS

A retrospective chart review of patients with DILS who were referred to an outpatient facility for human immunodeficiency virus (HIV)-positive individuals between 1994 and 2003 was performed. DILS was diagnosed as suggested by previous criteria. Demographic features and relevant clinical, laboratory, and radiologic data were recorded and results analyzed.

RESULTS

A total of 129 patients with DILS were identified. Of them, 56 (43%) were African American, 41 (32%) were white, and 32 (25%) were Hispanic. Parotid gland swelling appeared to be the sine qua non of DILS. Twenty-seven percent of patients had opportunistic infections. The status of 103 patients was available as of December 2003: 26 (25%) had died, of which only 6 (6%) succumbed to opportunistic infections. The prevalence of DILS had significantly decreased in the post-HAART era (1998 onwards) compared with that of the pre-HAART period (P < 0.000001). The prevalence of lymphocytic interstitial pneumonitis had also dropped significantly following introduction of HAART therapy (P = 0.015). A higher frequency of certain HLA class II alleles (DRB1) was found in African Americans with DILS compared with those with HIV without DILS (P = 0.006).

CONCLUSION

The epidemiology, clinical presentation, and certain extraglandular manifestations of DILS have changed, concomitant with the introduction of HAART, further suggesting that DILS is an antigen (viral)-driven response and the primary treatment for it is anti-HIV therapy.

[HIV infection and the kidneys (part I)]

HIV- (Human Immunodeficiency Virus) infected patients may be faced with a variety of renal problem patterns. Acute renal failure is common and most often the result of sepsis, hypertension, and toxic agents. Besides acute renal failure, HIV-associated nephropathy occurs in many HIV-positive patients, representing a unique pattern of sclerosing glomerulopathy. Many authors consider it to be the most rapidly progressive form of focal segmental sclerosis.

Host genetics of HIV-1 susceptibility

Susceptibility to HIV-1 and the rate of disease progression reflect the influence of the genetic diversity of the virus as well as the variation in host factors. The virus will co-evolve with the host, escaping and adapting to host-determined influences. Dominant host factors currently identified include diversity in the major histocompatibility complex class I, and alleles of chemokine, chemokine receptor and cytokine genes. Recent work proposes new variants in life cycle genes and in antiviral innate defense, which modify HIV-1 susceptibility. Comparative genomics generates information on host cell barriers that may explain the current distribution of these viruses among human and nonhuman primates. A greater understanding of the genetic basis of human susceptibility to HIV-1 contributes to an understanding of the pathogenesis of the disease, helps identify new targets for prophylaxis and vaccine development and will lead to predictive tools to identify those at risk of rapid disease progression.

Hepatitis C virus-associated oral lichen planus: is the geographical heterogeneity related to HLA-DR6?

BACKGROUND

The association between hepatitis C virus (HCV) and oral lichen planus (OLP) is more common in the Mediterranean area and Japan, possibly because of immunogenetic factors.

METHODS

Intermediate-resolution HLA-DRB typing by hybridization with oligonucleotide probes was performed in 31 Italian OLP patients with HCV infection, in 45 Italian OLP and in 48 British OLP patients without HCV infection. As healthy controls we included data from 145 unrelated Italian and 101 unrelated British bone marrow donors.

RESULTS

Italian HCV+ve OLP patients possessed the HLA-DR6 allele more frequently than Italian and British OLP patients without HCV infection (51.6% vs. 17.7% vs. 16.7%; P corrected = 0.028 and 0.017, respectively). There was no difference in the frequency of the HLA-DR6 allele between Italian and British control subjects.

CONCLUSIONS

The present data suggest that HLA-DR6 may be responsible for the peculiar geographic heterogeneity of the association between HCV and OLP.

Myositis in infiltrative lymphocytosis syndrome: clinicopathological observations and treatment

Diffuse infiltrative lymphocytosis syndrome (DILS) is characterized by the presence of persistent circulating CD8 lymphocytosis and visceral CD8 lymphocytic infiltration, predominantly in the salivary glands and lungs in a subset of human immunodeficiency virus (HIV) patients. Myositis has been rarely documented in DILS. We report here the histopathological abnormalities and treatment response of an HIV patient with DILS associated myositis. Muscle biopsy revealed features of polymyositis but electron microscopy study showed intranuclear filamentous inclusions of 18 nm diameter, without intracytoplasmic inclusion. Treatment with intravenous immunoglobuline was useful.

Genetic studies of pulmonary arterial hypertension

These genetic studies of primary pulmonary hypertension (PPH) initially tried to define immunogenetic subsets. Because only small subsets could be classified when defined by HLA/autoantibody associations and the familial form of PPH failed to segregate with the HLA class II locus, the focus shifted to a genome scan of families with PPH (FPPH). This approach identified a gene on chromosome 2q33,34 called PPH1. Mutations in this gene, now known to be bone morphogenetic protein receptor 2 (BMPR2), can cause PPH. Mutations in a second gene, ALK-1, present in families with hereditary hemorrhagic telangiectasia type 2, also causes PPH. Both genes, involved in TGF-B signaling, provide exciting clues for defining the pathogenesis of PPH.

The influence of HLA genotype on AIDS

Genetic resistance to infectious diseases is likely to involve a complex array of immune-response and other genes with variants that impose subtle but significant consequences on gene expression or protein function. We have gained considerable insight into the genetic determinants of HIV-1 disease, and the HLA class I genes appear to be highly influential in this regard. Numerous reports have identified a role for HLA genotype in AIDS outcomes, implicating many HLA alleles in various aspects of HIV disease. Here we review the HLA associations with progression to AIDS that have been consistently affirmed and discuss the underlying mechanisms behind some of these associations based on functional studies of immune cell recognition.

Lymphoid interstitial pneumonia: a narrative review

Lymphoid interstitial pneumonia (LIP) is regarded as both a disease and a nonneoplastic, inflammatory pulmonary reaction to various external stimuli or systemic diseases. It is an uncommon condition with incidence and prevalence rates that are largely unknown. Liebow and Carrington originally classified LIP as an idiopathic interstitial pneumonia in 1969. Although LIP had since been removed from that category, the most recent consensus classification sponsored by the American Thoracic Society and the European Respiratory Society recognizes that some cases remain idiopathic in origin, and its clinical, radiographic, and pathologic features warrant the return of LIP to its original classification among the idiopathic interstitial pneumonias. LIP also belongs within a spectrum of pulmonary lymphoproliferative disorders that range in severity from benign, small, airway-centered cellular aggregates to malignant lymphomas. It is characterized by diffuse hyperplasia of bronchus-associated lymphoid tissue. The dominant microscopic feature of LIP is a diffuse, polyclonal lymphoid cell infiltrate surrounding airways and expanding the lung interstitium. Classically, LIP occurs in association with autoimmune diseases, most often Sjögren syndrome. This has led to consideration of an autoimmune etiology for LIP, but its pathogenesis remains poorly understood. Persons who are seropositive for HIV, and children in particular, are at increased risk of acquiring LIP. Some studies suggest causal roles for both HIV and Epstein-Barr virus. The incidence of LIP is approximately twofold greater in women than men. The average age at diagnosis is between 52 years and 56 years. Symptoms of progressive cough and dyspnea predominate. There is great variability in the clinical course of LIP, from resolution without treatment to progressive respiratory failure and death. Although LIP is often regarded as a steroid-responsive condition, and oral corticosteroids continue to be the mainstay of therapy, response is unpredictable. Approximately 33 to 50% of patients die within 5 years of diagnosis, and approximately 5% of cases of LIP transform to lymphoma.

Spreading of HIV-specific CD8+ T-cell repertoire in long-term nonprogressors and its role in the control of viral load and disease activity

Long-term non-progressors (LTNP) represent a minority of human immunodeficiency virus (HIV) infected individuals characterized by stable or even increasing CD4+ T-cell count and by stronger immune responses against HIV than progressors. In this study, HIV-specific effector CD8+ T cells, as detected by both a sensitive ex vivo enzyme-linked immunospot (ELISPOT) assay and specific major histocompatibility complex (MHC) peptide tetramers, were at a low frequency in the peripheral blood of LTNP, and recognized a lower number of HIV peptides than their memory resting cell counterparts. Both factors may account for the lack of complete HIV clearance by LTNP, who could control the viral spread, and displayed a higher magnitude of cytotoxic T lymphocyte (CTL) responses than progressors. By combining cell purification and ELISPOT assays this study demonstrates that both effector and memory resting cells were confined to a CD8+ population with memory CD45RO+ phenotype, with the former being CD28- and the latter CD28+. Longitudinal studies highlighted a relatively stable HIV-specific effector repertoire, viremia, and CD4+ T-cell counts, which were all correlated with maintenance of nonprogressor status. In conclusion, the analysis of HIV-specific cellular responses in these individuals may help define clear correlates of protective immunity in HIV infection.

Increased frequency of HLA-DR6 allele in Italian patients with hepatitis C virus-associated oral lichen planus

BACKGROUND

Recent controlled studies have confirmed that hepatitis C virus (HCV) is the main correlate of liver disease in patients with lichen planus (LP), mainly in southern Europe and Japan. However, a low prevalence of HCV infection has been found in LP patients in England and northern France, and significant differences in serum HCV RNA levels or HCV genotypes have not been found between LP patients and controls. Thus host rather than viral factors may be prevalent in the pathogenesis of HCV-related LP. The HLA-DR allele may influence both the outcome of HCV infection and the appearance of symptoms outside the liver.

OBJECTIVES

To assess whether major histocompatibility complex class II alleles play a part in the development of HCV-related LP.

METHODS

Intermediate-resolution DRB typing by hybridization with oligonucleotide probes was performed in 44 consecutive Italian oral LP (OLP) patients with HCV infection (anti-HCV and HCV RNA positive), in an age, sex and clinically comparable disease control group of 60 Italian OLP patients without HCV infection (anti-HCV and HCV RNA negative), and in 145 healthy unrelated Italian bone marrow donors without evidence of liver disease or history of LP and with negative tests for HCV.

RESULTS

Patients with exclusive OLP and HCV infection possessed the HLA-DR6 allele more frequently than patients with exclusive OLP but without HCV infection (52% vs. 18%, respectively; Pc (Pcorrected) = 0.028, relative risk = 4.93). We did not find any relationship between mucocutaneous LP, HCV infection and HLA-DR alleles.

CONCLUSIONS

HCV-related OLP therefore appears to be a distinctive subset particularly associated with the HLA class II allele HLA-DR6. This could partially explain the peculiar geographical heterogeneity of the association between HCV and LP.

The changing spectrum of rheumatic disease in human immunodeficiency virus infection

CONTEXT

Although it has been known for over 15 years that a number of rheumatic diseases occur in patients with human immunodeficiency virus (HIV) infection, increasing knowledge about these disorders and advances in HIV treatment need to be considered in approaching patients with HIV-associated rheumatic disease.

OBJECTIVE

To examine the clinical, pathologic, and therapeutic features of HIV-associated rheumatic diseases in the context of what is known about the immunology of HIV infection.

DATA SOURCES

The author's own extensive collection of references, supplemented by PubMed Medline searches for articles in English-language journals published between 1985 and 2000. The indexing term HIV and the following coindexing terms were used for searching: arthritis, Reiter's syndrome, psoriatic arthritis, rheumatoid arthritis, osteonecrosis, vasculitis, pulmonary hypertension, myositis, myopathy, fibromyalgia, septic arthritis, parotid enlargement, diffuse infiltrative lymphocytosis syndrome, systemic lupus erythematosus, septic arthritis, mycobacterial arthritis, fungal arthritis, autoantibodies, anti-cardiolipin antibodies, and anti-neutrophilic cytoplasmic antibodies.

STUDY SELECTION

All papers identified in the literature search were reviewed. Studies presenting data that merely confirmed previous studies were not included in the analysis.

DATA EXTRACTION

All identified papers were abstracted by the author. Letters to the editor were included only if a new observation had been made.

DATA SYNTHESIS

This was a qualitative review of papers published, with new knowledge about these disorders summarized and presented.

RESULTS

Despite new treatments for HIV, reports of rheumatic diseases presenting in AIDS patients persist, especially in HIV-associated arthritis, diffuse infiltrative lymphocytosis syndrome, HIV-associated vasculitis, and polymyositis. However, new HIV treatments may ameliorate these diseases.

CONCLUSIONS

The spectrum of HIV-associated rheumatic disease remains a diagnostic and therapeutic challenge for the clinician. The impact of changes in HIV treatment on these disorders requires further assessment.

TNF-alpha gene polymorphism: clinical and biological implications

TNF-alpha is a proinflammatory cytokine that has been implicated in the severity of different immune-regulated diseases including autoimmune diseases and transplantation. The gene for TNF-alpha is located within the MHC region on chromosome 6p21.3. This is a highly polymorphic region, and the TNF-alpha itself contains a large number of polymorphisms. Some of these polymorphisms form extended haplotypes with the HLA class I and II alleles. TNF polymorphisms have been investigated in different diseases and most often whenever there is an HLA association with the disease (for example IDDM and RA) association(s) with TNF polymorphisms has been described. There are many studies on the function of the TNF polymorphisms showing the influence of the different alleles on the in vitro and in vivo levels of TNF production. However, recent studies in animal models suggest that not only polymorphisms within the TNF cluster are important in the regulation of TNF production but also the receptors as well (TNF R). This suggests that investigating polymorphisms within the TNF cluster and TNF receptors will be important in understanding the role of TNF regulation in a given disease.

Benign monoclonal expansion of CD8+ lymphocytes in HIV infection

BACKGROUND

A transient expansion of the CD8+ T cell pool normally occurs in the early phase of HIV infection. Persistent expansion of this pool is observed in two related settings: diffuse infiltrative lymphocytosis syndrome (DILS) and HIV associated CD8+ lymphocytosis syndrome.

AIM

To investigate a group of HIV infected patients with CD8+ lymphocytosis syndrome with particular emphasis on whether monoclonality was present.

METHODS

A group of 18 patients with HIV-1 infection and persistent circulating CD8+ lymphocytosis was compared with 21 HIV positive controls. Serum samples were tested for antinuclear antibodies, antibodies to extractable nuclear antigens, immunoglobulin levels, paraproteins, human T lymphotropic virus type 1 (HTLV-1), Epstein-Barr virus, and cytomegalovirus serology. Lymphocyte phenotyping and HLA-DR typing was performed, and T cell receptor (TCR) gene rearrangement studies used to identify monoclonal populations of T cells. CD4+ and CD8+ subsets of peripheral blood lymphocytes were purified to determine whether CD8+ populations inhibited HIV replication in autologous CD4+ cells.

RESULTS

A subgroup of patients with HIV-1 infection was found to have expanded populations of CD8+ T cell large granular lymphocytes persisting for 6 to 30 months. The consensus immunophenotype was CD4- CD8+ DRhigh CD11a+ CD11c+ CD16- CD28+/- CD56- CD57+, consistent with typical T cell large granular lymphocytes expressing cellular activation markers. Despite the finding of monoclonal TCR gene usage in five of 18 patients, there is evidence that the CD8+ expansions are reactive populations capable of mediating non-cytotoxic inhibition of HIV replication.

CONCLUSIONS

A subgroup of HIV positive patients has CD8+ lymphocytosis, but despite the frequent occurrence of monoclonal TCR gene usage there is evidence that this represents an immune response to viral infection rather than a malignant disorder.

Interactions of HIV-1 with antigen-presenting cells

There is currently much interest in the numerical and functional loss of antigen-presenting cells (APC) in HIV-1 disease and the contribution that this may make to HIV-1 pathology. The HIV-1 virus can interfere with the normal function of APC in a number of ways involving inappropriate signalling. These include changes in cytokine balance, cell-surface molecule expression and intracellular signalling pathways. This review examines how HIV-1 is able to disregulate APC function and discusses possible outcomes for the function of the immune system.

Combined Genotypes of CCR5, CCR2, SDF1, and HLA Genes Can Predict the Long-Term Nonprogressor Status in Human Immunodeficiency Virus-1–Infected Individuals

Human immunodeficiency virus (HIV)-1–infected long-term nonprogressors (LT-NP) represent less than 5% of HIV-1–infected patients. In this work, we tried to understand whether combined genotypes of CCR5-▵32, CCR2-64I, SDF1-3′A and HLA alleles can predict the LT-NP status. Among the chemokine receptor genotypes, only the frequency of the CCR5-▵32 allele was significantly higher in LT-NP compared with the group of standard progressors. The predominant HLA alleles in LT-NP were HLA-A3, HLA-B14, HLA-B17, HLA-B27, HLA-DR6, and HLA-DR7. A combination of both HLA and chemokine receptor genotypes integrated in a multivariate logistic regression model showed that if a subject is heterozygous for CCR5-▵32 and homozygous for SDF1 wild type, his odds of being LT-NP are increased by 16-fold, by 47-fold when a HLA-B27 allele is present with HLA-DR6 absent, and by 47-fold also if at least three of the following alleles are present: HLA-A3, HLA-B14, HLA-B17, HLA-DR7. This model allowed a correct classification of 70% of LT-NPs and 81% of progressors, suggesting that the host’s genetic background plays an important role in the evolution of HIV-1. The chemokine receptor and chemokine genes along with the HLA genotype can serve as predictors of HIV-1 outcome for classification of HIV-1–infected subjects as LT-NPs or progressors.

Combined Genotypes of CCR5, CCR2, SDF1, and HLA Genes Can Predict the Long-Term Nonprogressor Status in Human Immunodeficiency Virus-1–Infected Individuals

Human immunodeficiency virus (HIV)-1–infected long-term nonprogressors (LT-NP) represent less than 5% of HIV-1–infected patients. In this work, we tried to understand whether combined genotypes of CCR5-▵32, CCR2-64I, SDF1-3′A and HLA alleles can predict the LT-NP status. Among the chemokine receptor genotypes, only the frequency of the CCR5-▵32 allele was significantly higher in LT-NP compared with the group of standard progressors. The predominant HLA alleles in LT-NP were HLA-A3, HLA-B14, HLA-B17, HLA-B27, HLA-DR6, and HLA-DR7. A combination of both HLA and chemokine receptor genotypes integrated in a multivariate logistic regression model showed that if a subject is heterozygous for CCR5-▵32 and homozygous for SDF1 wild type, his odds of being LT-NP are increased by 16-fold, by 47-fold when a HLA-B27 allele is present with HLA-DR6 absent, and by 47-fold also if at least three of the following alleles are present: HLA-A3, HLA-B14, HLA-B17, HLA-DR7. This model allowed a correct classification of 70% of LT-NPs and 81% of progressors, suggesting that the host’s genetic background plays an important role in the evolution of HIV-1. The chemokine receptor and chemokine genes along with the HLA genotype can serve as predictors of HIV-1 outcome for classification of HIV-1–infected subjects as LT-NPs or progressors.

Virological and Immunological Features of Long-Term Human Immunodeficiency Virus–Infected Individuals Who Have Remained Asymptomatic Compared With Those Who Have Progressed to Acquired Immunodeficiency Syndrome

Infection with the human immunodeficiency virus (HIV) leads to a decrease in CD4+ T cells and disease progression within a decade of seroconversion. However, a small group of infected people, despite being infected by HIV for 10 or more years, remain clinically asymptomatic and have stable CD4+ cell counts without taking antiretroviral medication. To determine why these individuals, known as long-term survivors (LTS), remain healthy, the hematological profiles, viral load and properties, HIV coreceptor genotype, and anti-HIV immune responses of these people were compared with those of individuals who have progressed to disease (Progressors) over the same time period. Unlike Progressors, LTS have a low circulating viral load and a low number of HIV-infected cells. These differences in the levels of the viral load were not associated with a dominant biologic viral phenotype, varying growth kinetics of the virus, mutation in the cellular CCR5 gene, or the presence of neutralizing antibodies. Importantly, the difference in viral load could be explained by the enhanced ability of CD8+ cells from LTS to suppress HIV replication.

© 1998 by The American Society of Hematology.

Virological and Immunological Features of Long-Term Human Immunodeficiency Virus–Infected Individuals Who Have Remained Asymptomatic Compared With Those Who Have Progressed to Acquired Immunodeficiency Syndrome

Infection with the human immunodeficiency virus (HIV) leads to a decrease in CD4+ T cells and disease progression within a decade of seroconversion. However, a small group of infected people, despite being infected by HIV for 10 or more years, remain clinically asymptomatic and have stable CD4+ cell counts without taking antiretroviral medication. To determine why these individuals, known as long-term survivors (LTS), remain healthy, the hematological profiles, viral load and properties, HIV coreceptor genotype, and anti-HIV immune responses of these people were compared with those of individuals who have progressed to disease (Progressors) over the same time period. Unlike Progressors, LTS have a low circulating viral load and a low number of HIV-infected cells. These differences in the levels of the viral load were not associated with a dominant biologic viral phenotype, varying growth kinetics of the virus, mutation in the cellular CCR5 gene, or the presence of neutralizing antibodies. Importantly, the difference in viral load could be explained by the enhanced ability of CD8+ cells from LTS to suppress HIV replication.

© 1998 by The American Society of Hematology.

Chemokine receptors and their crucial role in human immunodeficiency virus infection: major breakthroughs in HIV research

Within the last three years, major progress in the understanding of acquired immune deficiency syndrome pathogenesis has been achieved. The discovery that human immunodeficiency virus (HIV), in addition to the CD4 receptor, requires the presence of a coreceptor in order to infect cells has led to a series of breakthroughs in HIV research and knowledge. These include an increased understanding of viral entry, a connection of viral phenotype to specific coreceptor use, and an unequivocal linkage of a single human gene to host susceptibility. All in all these achievements provide a number of promising new strategies for combating HIV.

Low relative frequencies of CD26(+) CD4(+) cells in long-term nonprogressing human immunodeficiency virus type 1-infected subjects

A broad antibody panel was used for immunophenotyping of human immunodeficiency virus type 1 (HIV-1)-infected patients who were long-term nonprogressors (LTNP). The LTNP were compared with patients in the early phase of infection and patients who had progressed to advanced immunodeficiency. Changes in CD8(+) subset distribution were observed mainly at acquisition of HIV-1 infection, whereas CD4(+) subset changes appeared during progression of HIV-1 infection. The decreasing levels of CD4(+) cells were characterized by an increasing frequency of cells expressing the activation markers HLA-Dr and CD45RO but not the CD28 surface antigen. The LTNP exhibited significant changes compared to HIV-negative patients in almost all markers. Compared to patients in the early phase of infection, the only difference was a relatively lower frequency of CD4(+) cells expressing CD26 among the LTNP. The results show that HIV-1-infected persons who have no signs of immunodeficiency despite many years of infection have an immunophenotypic pattern that is substantially different from that of noninfected persons. Despite the long duration of infection, the LTNP exhibit a pattern similar to that of newly infected persons, with the exception of lower expression of CD26 on CD4(+) cells.

A vigorous virus-specific CD4+ T cell response may contribute to the association of HLA-DR13 with viral clearance in hepatitis B

A strong virus-specific CD4+ and CD8+ T lymphocyte response to hepatitis B virus (HBV) has been associated with viral clearance, but little is known about factors determining the individual's ability to mount such a T cell response. Recently a strong association between the HLA class II allele DR13 and a self-limited course of HBV infection has been described. In the present study of 33 patients with acute hepatitis B we show that individuals carrying HLA-DR13 mount a more vigorous CD4+ T cell response to HBV core (5706 ct/min (25th/75th percentile 3239 ct/min; 10,552 ct/min)) than patients without HLA-DR 13 (1365 ct/min (490 ct/min; 5334 ct/min); P = 0.006). However, peptide epitopes aa 50-69, aa 61-85, and aa 81-105 were recognized most frequently by both patient groups. Moreover, among 14 HBV core-specific CD4+ T cell clones from two patients with HLA-DR13, only one T cell clone was HLA-DR13-restricted. Our data suggest that the beneficial effect of the HLA-DR13 alleles on the outcome of HBV infection could be explained by a more vigorous HBV core-specific CD4+ T cell response, which may either be due to more proficient antigen presentation by the HLA-DR13 molecules themselves or a linked polymorphism in a neighbouring immunoregulatory gene.

Influence of host genes on HIV-1 disease progression

The role of host genes in the course of HIV-1 infection has been examined in different populations and among all major risk groups. Two extended human lymphocyte antigen (HLA) haplotypes, HLA A1-Cw7-B8-DR3-DQ2 and HLA A11-Cw4-B35-DR1-DQ1, are found to be associated with a faster progression to AIDS. The complement C4 factor and tumor necrosis factor genes of the major histocompatibility complex, as well as the mannose binding protein gene, have also been suggested to influence the outcome of AIDS. The recent discovery that chemokine receptors could serve as cofactors for HIV-1 cell entry has prompted a search for polymorphisms in chemokine receptor genes. A 32 base pair inactivating deletion in the CCR5 gene and a point mutation within the CCR2b gene resulting in a conservative amino acid substitution have been examined and shown to be independently associated with delayed disease progression. Together, these observations strongly support a genetic component in AIDS pathogenesis. This article synthesizes the current state of knowledge about the influence of host genes on HIV-1 disease progression. It provides a summary of all significant association studies reported so far. The role of the allelic polymorphism in these genes is discussed with regard to the immunopathogenesis of AIDS.

HIV type 1 envelope glycoprotein 120 carboxy-terminal peptide-induced human T cell lines selectively suppress heterogeneous proliferative T cell responses to soluble antigens

It has been proposed that the highly conserved human immunodeficiency virus type 1 (HIV-1) envelope gp120 carboxy-terminal sequence, TKAKRRVVEREKR (CT120), may represent a functional mimic of the human leukocyte antigen (HLA) class II DR beta-chain third hypervariable region (HVR3) sequence motif located at position 69-81. Presentation of this potentially pathogenic fragment by HLA class I and/or II molecules, in a manner analogous to the indirect pathway of allorecognition, may induce both widespread cellular activation and also break self-tolerance, resulting in the selective and progressive anti-self HLA class II-directed immune suppression, which is a central feature of HIV-1 infection and the associated acquired immune deficiency syndrome (AIDS). To investigate the functional role of the HIV-1 gp120 C-terminal fragment T cell lines (TCLs) were raised from three healthy HIV-1-seronegative subjects at low risk of HIV-1 exposure, by repeated stimulation with a short synthetic 13-mer CT120 peptide in vitro. Graded concentrations (10[3] to 5 x 10[4]) of CT120 TCLs suppressed the primary 6-day proliferation of autologous PBMCs in response to the soluble antigens tetanus toxoid (TT) and purified protein derivative (PPD). In contrast, CT120 TCLs demonstrated no suppressive effect on 3-day phytohemagglutinin (PHA), concanavalin A (ConA), and pokeweed mitogen (PWM) mitogenic responses. Fractionation of CT120 TCLs into highly purified CD4+ and CD8+ T cell subsets demonstrated that the CD8+ T cell fraction mediated the suppressor effector function. HLA restriction analysis revealed a complex pattern as both anti-HLA class II DR and anti-HLA class I (A, B, C) MAbs inhibited proliferation of oligoclonal CD8+ CT120 TCLs. Strategies aimed at specifically inhibiting such putative immunopathogenic HIV-1-encoded T cell epitopes may be an important consideration for development of future HIV-1 immunotherapy.

Host factors in the pathogenesis of HIV disease

Host factors play an important role in determining rates of disease progression in human immunodeficiency virus (HIV)-infected individuals. HIV is able to subvert the host immune system by infecting CD4+ T cells that normally orchestrate immune responses and by inducing the secretion of proinflammatory cytokines that the virus can utilize to its own replicative advantage. The recognition that certain chemokine receptors serve as necessary co-factors for HIV entry into its target cells as well as the fact that ligands for these receptors can modulate the efficiency of HIV infection has expanded the number and scope of host factors that may impact the pathogenesis of HIV disease. This area of investigation will no doubt yield novel therapeutic strategies for intervention in HIV disease; however, caution is warranted in light of the enormous complexity of the pleiotropic cytokine and chemokine networks and the uncertainty inherent in manipulating these systems. HIV-infected long-term non-progressors represent an excellent model to study potential host factors involved in HIV disease pathogenesis. Genetic factors certainly have a major impact on the immune responses mounted by the host. In this regard, a polymorphism in the gene for the HIV co-receptor CC chemokine receptor 5 (CCR5), which serves as a co-receptor for macrophage (M)-tropic strains of HIV, affords a high degree of protection against HIV infection in individuals homozygous for the genetic defect and some degree of protection against disease progression in HIV-infected heterozygotes. HIV-specific immune responses, including cytotoxic T-lymphocyte (CTL) responses and neutralizing antibody responses, also appear to play salutary roles in protecting against disease progression.

Influence of HLA alleles on the rate of progression of vertically transmitted HIV infection in children: association of several HLA-DR13 alleles with long-term survivorship and the potential association of HLA-A*2301 with rapid progression to AIDS. Long-Term Survivor Study

The influence of host immunogenetics on the outcome of vertically transmitted HIV infection in children was examined in a multicenter cross sectional study of long term survivors and rapid progressors. Sequence-based typing was performed for the DRB1, DQB1 and HLA-A loci. 36.7% of 30 children surviving more than 8 years had one or more of the HLA-DR13 alleles, versus none of 14 rapidly progressing children who died within 2 years of age, p = 0.009, Haldane RR = 17.1. The alleles variably associated with this beneficial response to HIV were: DRB1*1301, DRB1*1302, DRB1*1303 and DRB1*1310, suggesting that the DR13 effect acted as a dominant trait. An additional 6 children were typed only by the SSOP method resulting in 44.4% of 36 long term surviving children with a DR13 allele and none of 14 rapid progressors, p = 0.002, Haldane RR = 23.3. No single DQB1 allele accounted for the HLA-DR13 allele association. In contrast, the presence of HLA A*2301 was associated with rapid progression to AIDS, 4% of long term survivors vs. 57.1% of 7 rapid progressors, p = 0.0006, RR = 0.031. Although the sample size is small, the marked differences in allele frequency along with differences between the peptide binding pockets of the HLA-A9 group of alleles including HLA A*2301 and the remainder of the HLA-A alleles suggest a structural basis for the dominant disadvantageous immune response to HIV conferred by A*2301.

Peripheral neuropathy in human immunodeficiency virus-infected patients with the diffuse infiltrative lymphocytosis syndrome

A subset of human immunodeficiency virus (HIV)-infected patients develop persistent CD8 hyperlymphocytosis and a Sjogren's syndrome-like syndrome associated with multivisceral CD8 T-cell infiltration, known as the diffuse infiltrative lymphocytosis syndrome (DILS). Patients with DILS tend to have higher CD4 cell counts, fewer opportunistic infections, and longer survival times than other HIV-infected patients. Peripheral nerve involvement in DILS has been poorly documented. We studied 12 HIV-infected patients with CD8 hyperlymphocytosis, DILS, and clinical signs of peripheral neuropathy. Two of 4 patients who were HLA typed were HLA-DR5 and 1 was HLA-DR6. All patients had the sicca syndrome and multivisceral involvement. The neuropathy was acute or subacute, always painful, and symmetrical in 8 cases. Electrophysiology was consistent with axonal neuropathy in 10 of 12 patients. Nerve biopsy showed marked angiocentric CD8 infiltrates without mural necrosis (12 of 12), and abundant expression of HIV p24 protein in macrophages (12 of 12). The HIV genome was detected by polymerase chain reaction in nerve homogenates. Zidovudine therapy was associated with improvement in 6 of 6 patients and steroid therapy was beneficial in 4 of 5 patients. No T-cell lymphoma was observed during follow-up, but 2 patients developed a primary B-cell lymphoma. We conclude that DILS neuropathy represents HIV-associated neuropathy, characterized by marked CD8 infiltration and abundant HIV in nerve, that improves with zidovudine or steroid therapy, and probably reflects a systemic host-determined and antigen-driven response to HIV.

Tumour necrosis factor c2 microsatellite allele is associated with the rate of HIV disease progression

BACKGROUND

The rate of immunological deterioration and progression to AIDS differs markedly between HIV-positive individuals, and may be influenced by cofactors, HIV phenotype and host T-cell response. Tumour necrosis factor (TNF)-alpha and lymphotoxin stimulate HIV replication and may induce apoptosis of HIV-infected and uninfected lymphocytes in vitro, thus accelerating disease progression and CD4 depletion. Variability in TNF production between individuals is to a degree genetically determined and may be predicted from polymorphisms of microsatellite regions surrounding the human TNF gene locus.

METHODS

We examined TNf microsatellite polymorphisms in 24 HIV-positive patients with slower disease progression (CD4 count > 400 x 10(6)/l at > or = 6 years), 20 HIV-positive patients with faster progression (CD4 count < 200 x 10(6)/l within 5 years) and 109 healthy controls resident in north-west England. Typing was performed by polymerase chain reaction amplification of TNF a, b, c and d microsatellites and alleles were defined using fluorescence-based semi-automated microsatellite mapping techniques.

RESULTS

No significant differences in TNF a, b and d allele frequencies were observed between faster and slower progressors, or with healthy controls. The frequency of the TNF c2 allele was significantly different between HIV-positive slower (60.9%) and faster (15%) progressors (P = 0.002) with an odds ratio of 0.1 (95% confidence interval, 0-0.6). TNF c2 was also less frequent in faster progressors than in healthy controls (45.9%, P = 0.006) with an odds ratio of 0.2 (95% confidence interval 0-0.8).

CONCLUSIONS

This is the first report demonstrating a strong association between the TNF c2 allele and the rate of HIV progression. Although it is possible that this finding may have arisen as a result of linkage disequilibrium with other alleles within the major histocompatibility complex that exert a more powerful effect upon progression, evidence is mounting to suggest that both TNF-alpha and lymphotoxin are closely involved in HIV disease progression and CD4 depletion. Our results serve to highlight the potential importance of genetic polymorphism, particularly of the TNF locus, in influencing the progression of HIV infection.

Adult immunodeficiency and rheumatic disease

Several rheumatic illnesses may develop in adults with primary or acquired immunologic defects. Individuals with primary defects in B-cell antibody production, such as common variable immunodeficiency of selective IgA deficiency, and those with defects of complement components, have an increased prevalence of systemic lupus erythematosus--like syndromes or other autoimmune diseases. Defects in immunoglobulin production may be complicated by inflammatory or infectious arthritis. Infection with HIV-1 may be associated with diverse rheumatic conditions, including diffuse infiltrative lymphocytosis syndrome, myopathies, vasculitides, inflammatory arthritides, and infectious musculoskeletal complications. An approach to these disorders that takes into consideration the underlying mechanism of disease is presented. Appropriate strategies aimed at treatment of the underlying immunodeficiency may improve the clinical course of the associated rheumatic disorder.

Toward an understanding of the correlates of protective immunity to HIV infection

Considerable progress has been made recently in understanding the genetic, immunologic and virologic factors in human immunodeficiency virus (HIV)-infected individuals who either rapidly progress or do not progress to acquired immunodeficiency syndrome (AIDS). In addition, detection of HIV-specific immune responses in HIV-negative individuals who have been exposed to the virus multiple times suggests that natural immune responses to HIV may be protective in rare individuals. Understanding the correlates of protective immunity to HIV infection is critical to efforts to develop preventive HIV vaccines as well as to determine the feasibility of treating HIV infection by boosting immunity to HIV.

Major histocompatibility complex class II DR alleles DRB1*1501 and those encoding HLA-DR13 are preferentially associated with a diminution in maternally transmitted human immunodeficiency virus 1 infection in different ethnic groups: determination by an automated sequence-based typing method

Transmission of human immunodeficiency virus 1 (HIV-1) from an infected women to her offspring during gestation and delivery was found to be influenced by the infant's major histocompatibility complex class II DRB1 alleles. Forty-six HIV-infected infants and 63 seroreverting infants, born with passively acquired anti-HIV antibodies but not becoming detectably infected, were typed by an automated nucleotide-sequence-based technique that uses low-resolution PCR to select either the simpler Taq or the more demanding T7 sequencing chemistry. One or more DR13 alleles, including DRB1*1301, 1302, and 1303, were found in 31.7% of seroreverting infants and 15.2% of those becoming HIV-infected [OR (odds ratio) = 2.6 (95% confidence interval 1.0-6.8); P = 0.048]. This association was influenced by ethnicity, being seen more strongly among the 80 Black and Hispanic children [OR = 4.3 (1.2-16.4); P = 0.023], with the most pronounced effect among Black infants where 7 of 24 seroreverters inherited these alleles with none among 12 HIV-infected infants (Haldane OR = 12.3; P = 0.037). The previously recognized association of DR13 alleles with some situations of long-term nonprogression of HIV suggests that similar mechanisms may regulate both the occurrence of infection and disease progression after infection. Upon examining for residual associations, only only the DR2 allele DRB1*1501 was associated with seroreversion in Caucasoid infants (OR = 24; P = 0.004). Among Caucasoids the DRB1*03011 allele was positively associated with the occurrence of HIV infection (P = 0.03).

Conservation of an intact human immunodeficiency virus type 1 vif gene in vitro and in vivo

Replication of vif-negative human immunodeficiency virus type 1 (HIV-1) is attenuated in certain cell lines and highly impaired in peripheral blood lymphocytes in vitro. To determine whether intact vif is positively selected during natural HIV-1 infection and to determine vif sequence variability, we employed PCR amplification, cloning, and sequencing to investigate the vif region of replicating virus in short-term-passage HIV-1 primary isolates from five asymptomatic individuals and from five persons with AIDS. A total of 46 vif clones were obtained and analyzed. Recombinant proviruses were constructed from selected vif clones from one patient and found to be fully infectious. We found that 38 of the 46 clones sequenced carried open vif reading frames and that there was a low degree of heterogeneity of vif genes within isolates from the same individual and among isolates from different donors. The cysteines previously found to be essential for vif protein function were conserved in all clones. A phylogenetic tree constructed from all available vif nucleotide sequences resulted in a virus grouping similar to those of gag and env. Direct sequencing of vif amplified by PCR from uncultured lymphocytes of 15 individuals at various stages of progression toward AIDS demonstrated vif open reading frames in 13 of 15 samples tested. There was no obvious correlation between disease status and the presence of an intact vif within this sample group at the time of sample procurement. The conservation of the vif open reading frame in vitro and in vivo and its limited variability following virus transmission in vitro are consistent with a role for vif in natural HIV-1 infection.