Neuropathy in diffuse infiltrative lymphocytosis syndrome: an HIV neuropathy, not a lymphoma

Article Topic: Neuropathies Due to Infections and Antimicrobial Treatments

Purpose of eview

The aim of this review is to discuss the presentation, diagnosis, and management of polyneuropathy (PN) in selected infections. Overall, most infection related PNs are an indirect consequence of immune activation rather than a direct result of peripheral nerve infection,  Schwann cell infection, or toxin production, though note this review will describe infections that cause PN through all these mechanisms. Rather than dividing them by each infectious agent separately, we have grouped the infectious neuropathies according to their presenting phenotype, to serve as a guide to clinicians. Finally, toxic neuropathies related to antimicrobials are briefly summarized.

Recent findings

While PN from many infections is decreasing, increasing evidence links infections to variants of GBS. Incidence of neuropathies secondary to use of HIV therapy has decreased over the last few years.

Summary

In this manuscript, a general overview of the more common infectious causes of PN will be discussed, dividing them across clinical phenotypes: large- and small-fiber polyneuropathy, Guillain-Barré syndrome (GBS), mononeuritis multiplex, and autonomic neuropathy. Rare but important infectious causes are also discussed.

Global HIV neurology: a comprehensive review

: Neurological conditions associated with HIV remain major contributors to morbidity and mortality and are increasingly recognized in the aging population on long-standing combination antiretroviral therapy (cART). Importantly, growing evidence shows that the central nervous system (CNS) may serve as a reservoir for viral replication, which has major implications for HIV eradication strategies. Although there has been major progress in the last decade in our understanding of the pathogenesis, burden, and impact of neurological conditions associated with HIV infection, significant scientific gaps remain. In many resource-limited settings, antiretrovirals considered second or third line in the United States, which carry substantial neurotoxicity, remain mainstays of treatment, and patients continue to present with severe immunosuppression and CNS opportunistic infections. Despite this, increased global access to cART has coincided with an aging HIV-positive population with cognitive sequelae, cerebrovascular disease, and peripheral neuropathy. Further neurological research in low-income and middle-income countries (LMICs) is needed to address the burden of neurological complications in HIV-positive patients, particularly regarding CNS viral reservoirs and their effects on eradication.

Contribution of HIV Infection, AIDS, and Antiretroviral Therapy to Exocrine Pathogenesis in Salivary and Lacrimal Glands

The structure and function of exocrine glands are negatively affected by human immunodeficiency virus (HIV) infection and its co-morbidities, including innate and adaptive immune responses. At the same time, exocrine function may also be influenced by pharmacotherapies directed at the infectious agents. Here, we briefly review the role of the salivary glands and lacrimal glands in normal physiology and exocrine pathogenesis within the context of HIV infection and acquired immune deficiency syndrome (AIDS), including the contribution of antiretroviral therapies on both. Subsequently, we discuss the impact of HIV infection and the types of antiretroviral therapy on disease management and therapy development efforts.

HIV neuropathology

Primary human immunodeficiency virus (HIV) neuropathologies can affect all levels of the neuraxis and occur in all stages of natural history disease. Some, like HIV encephalitis, HIV myelitis, and diffuse infiltrative lymphocytosis of peripheral nerve, reflect productive infection of the nervous system; others, like vacuolar myelopathy, distal symmetric polyneuropathy, and central and peripheral nervous system demyelination, are not clearly related to regional viral replication, and reflect more complex cascades of dysregulated host immunity and metabolic dysfunction. In pediatric patients, the spectrum of neuropathology is altered by the impacts of HIV on a developing nervous system, with microcephaly, abundant brain mineralization, and corticospinal tract degeneration as examples of this unique interaction. With efficacious therapies, CD8 T-cell encephalitis is emerging as a significant entity; often this is clinically recognized as immune reconstitution inflammatory syndrome, but has also been described in the context of viral escape and treatment interruption. The relationship of HIV neuropathology to clinical symptoms is sometimes straightforward, and sometimes mysterious, as individuals can manifest significant deficits in the absence of discrete lesions. However, at all stages of the natural history disease, neuroinflammation is abundant, and critical to the generation of clinical abnormality. Neuropathologic and neurobiologic investigations will be central to understanding HIV nervous system disorders in the era of efficacious therapies.

Relapsing CD8+ encephalitis-looking for a solution

CD8+ encephalitis (CD8+E) is an emerging and incompletely understood HIV-associated neurological syndrome, typically presenting as a steroid-responsive subacute encephalopathy with prominent white matter changes in patients with apparently well-controlled HIV infection. Some cases can be associated with the phenomenon of 'viral escape' (disproportionate replication within the cerebrospinal fluid), but the most important pathophysiology of CD8+E is thought to involve an attack on HIV-infected CD4+ lymphocytes by autoreactive CD8+ cells. We report a case of CD8+E where the initial positive response to steroid treatment was followed by several relapses on withdrawal. This led to the use of mycophenolate mofetil (MMF) as a long-term steroid-sparing agent, which is the first time this approach has been reported in the literature. The patient has now been on treatment with MMF for 10 months and it has been possible to taper the steroids down to a minimal maintenance dose without further relapse.

Encephalitis with infiltration by CD8+ lymphocytes in HIV patients receiving combination antiretroviral treatment

We report the neuropathological findings in 10 HIV-infected patients treated by combination antiretroviral therapy who developed subacute encephalopathy of rapidly progressive onset. Brain biopsy showed encephalitic lesions variably associated with myelin loss and slight axonal damage. There was inconstant, weak expression of HIV protein p24; tests for other pathogens were negative. The most striking feature was diffuse, perivascular and intraparenchymal infiltration by CD8+ T-lymphocytes. Six patients improved after the treatment. Four had an unfavorable outcome and died within a year. Post-mortem in one case confirmed HIV leukoencephalitis with p24-positive multinucleated giant cells, associated with acute demyelinating encephalomyelitis (ADEM) in the cerebellum. There was diffuse infiltration by CD8+ lymphocytes; CD4+ cells were virtually absent. These cases may represent a specific clinicopathological entity, of which a few comparable cases have been already described. They can be included in the wide framework of immune reconstitution disease. Such syndromes have been described with opportunistic infections, but only seldom with HIV infection of the central nervous system (CNS). Our findings support the hypothesis that CD8+ cytotoxic lymphocytes can be harmful in immune reconstitution disease, particularly in the absence of CD4+ lymphocytes. CD8 cytotoxicity produces an acutization of a smoldering infection and/or an immunopathological reaction similar to ADEM.

HIV peripheral neuropathy

Peripheral neuropathies are the most common neurological manifestations occurring in HIV-infected individuals. Distal symmetrical sensory neuropathy is the most common form encountered today and is one of the few that are specific to HIV infection or its treatment. The wide variety of other neuropathies is akin to the neuropathies seen in the general population and should be managed accordingly. In the pre-ART era, neuropathies were categorized according to the CD4 count and HIV viral load. In the early stages of HIV infection when CD4 count is high, the inflammatory demyelinating neuropathies predominate and in the late stages with the decline of CD4 count opportunistic infection-related neuropathies prevail. That scenario has changed with the present almost universal use of ART (antiretroviral therapy). Hence, HIV-associated peripheral neuropathies are better classified according to their clinical presentations: distal symmetrical polyneuropathy, acute inflammatory demyelinating polyradiculoneuropathy (AIDP) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), mononeuropathies, mononeuropathies multiplex and cranial neuropathies, autonomic neuropathy, lumbosacral polyradiculomyelopathy, and amyotrophic lateral sclerosis (ALS)-like motor neuropathy. Treated with ART, HIV-infected individuals are living longer and are at a higher risk of metabolic and age-related complications; moreover they are also prone to the potentially neurotoxic effects of ART. There are no epidemiological data regarding the incidence and prevalence of the peripheral neuropathies. In the pre-ART era, most data were from case reports, series of patients, and pooled autopsy data. At that time the histopathological evidence of neuropathies in autopsy series was almost 100%. In large prospective cohorts presently being evaluated, it has been found that 57% of HIV-infected individuals have distal symmetrical sensory neuropathy and 38% have neuropathic pain. It is now clear that distal symmetrical sensory neuropathy is caused predominantly by the ART's neurotoxic effect but may also be caused by the HIV itself. With a sizeable morbidity, the neuropathic pain caused by distal symmetrical sensory neuropathy is very difficult to manage; it is often necessary to change the ART regimen before deciding upon the putative role of HIV infection itself. If the change does not improve the pain, there are few options available; the most common drugs used for neuropathic pain are usually not effective. One is left with cannabis, which cannot be recommended as routine therapy, recombinant human nerve growth factor, which is unavailable, and topical capsaicin with its side-effects. Much has been done to and learned from HIV infection in humans; HIV-infected individuals, treated with ART, are now dying mostly from cardiovascular disease and non-AIDS-related cancers. It hence behooves us to find new approaches to mitigate the residual neurological morbidity that still impacts the quality of life of that population.

Neuromuscular manifestations of HIV/AIDS

The human immunodeficiency virus (HIV) epidemic, now entering its fourth decade, affects approximately 33 million people living in both developed and resource-limited countries. Neurological complications of the peripheral nervous system are common in HIV-infected patients, and neuromuscular pathology is associated with significant morbidity. Peripheral neuropathy is the most common neuromuscular manifestation observed in HIV/AIDS, and in the antiretroviral era, its prevalence has increased. The purpose of this review was to describe the clinical spectrum of neuromuscular disorders in the setting of HIV infection and to provide an approach to diagnosis and management.

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.

[HIV-associated neuropathies]

Human immunodeficiency virus (HIV)-associated polyneuropathy has become the most common neurological complication of HIV infection and is one of the main risk factors for development of a neuropathy worldwide. Therefore HIV should always be considered as an underlying cause in patients with neuropathy. Many types of peripheral neuropathies are seen in HIV infection depending on the stage of infection. The inflammatory demyelinating neuropathies both acute (Guillain-Barré syndrome, GBS) and chronic (chronic inflammatory demyelinating neuropathy, CIDP) occur mainly at the time of seroconversion or early in the course of the disease while syndromes associated with opportunistic infections like CMV (i.e. polyradiculoneuropathy) occur in the late phase of HIV infection and are related to the loss of immune function. Distal symmetrical polyneuropathy (DSP) is the most common neuropathy in HIV-infected patients. We review the clinical manifestations, epidemiology, clinical diagnostics, pathophysiology and management strategies for HIV-associated polyneuropathies.

HIV lumbosacral radiculoplexus neuropathy mimicking lymphoma: diffuse infiltrative lymphocytosis syndrome (DILS) restricted to nerve?

Diffuse infiltrative lymphocytosis syndrome (DILS) is a hyperimmune reaction against HIV. It leads to MHC-restricted clonal expansion of CD8 T cells characterized by circulating CD8 hyperlymphocytosis and CD8 T-cell infiltration in organs. Our patient presented with painful lumbosacral radiculoplexus neuropathy and tested positive for HIV. Nerve biopsy showed large collections of CD8 lymphocytes suspicious for lymphoma. Symptoms, signs, and repeat biopsy improved with antiretroviral treatment. The presentation and treatment response suggest that this case is localized DILS.

Neuromuscular diseases associated with HIV-1 infection

Neuromuscular disorders are common in human immunodeficiency virus (HIV); they occur at all stages of disease and affect all parts of the peripheral nervous system. These disorders have diverse etiologies including HIV itself, immune suppression and dysregulation, comorbid illnesses and infections, and side effects of medications. In this article, we review the following HIV-associated conditions: distal symmetric polyneuropathy; inflammatory demyelinating polyneuropathy; mononeuropathy; mononeuropathy multiplex; autonomic neuropathy; progressive polyradiculopathy due to cytomegalovirus; herpes zoster; myopathy; and other, rarer disorders.

Infectious Neuropathies

Peripheral neuropathies can result from several infective agents, ranging from viruses, especially retroviruses, to parasites and bacilli. Leprosy, which often is considered a disorder of the past, still is common in dome geographic areas, especially in Africa, South America, and Asia. An increasing number of cases of neuropathies occurs in patients who have HIV or Lyme disease. The important point is that all these neuropathies are treatable and often preventable.

Human immunodeficiency virus-associated peripheral neuropathies

Peripheral neuropathy has emerged as the most common neurologic complication of human immunodeficiency virus (HIV) infection. It will continue to play an Important role in HIV Infection given the fact that HIV-infected Individuals are living longer, are at risk of long-term metabolic complications, and face an Increasing exposure to potentially neurotoxic antiretroviral drugs. We review the various types of peripheral neuropathy that have been associated with HIV infection, including distal symmetrical polyneuropathy, toxic neuropathy from antiretroviral drugs, diffuse infiltrative lymphocytosis syndrome, inflammatory demyelinating polyneuropathies, multifocal mononeuropathies, and progressive polyradiculopathy.

Complications musculaires de l’infection par le virus de l’immunodéficience humaine (VIH) à l’ère des trithérapies

Introduction of highly active antiretroviral therapy (HAART) has dramatically modified the natural history of HIV disease, but lengthening the survival of HIV-infected individuals has been associated with an increasing prevalence of iatrogenic conditions. Muscular complications of HIV infection are classified as follows: (1) HIV-associated myopathies and related conditions including polymyositis, inclusion-body myositis, nemaline myopathy, diffuse infiltrative lymphocytosis syndrome (DILS), HIV-wasting syndrome, vasculitis, myasthenic syndromes, and chronic fatigue; (2) iatrogenic conditions including mitochondrial myopathies, HIV-associated lipodystrophy syndrome, and immune restoration syndrome; (3) opportunistic infections and tumor infiltrations of skeletal muscle; and (4) rhabdomyolysis. These features are described in the present review.

Bilateral panuveitis in HIV-1-infected patients with CD8 lymphocytosis

AIMS

To report the presence of HIV-1-infected patients with bilateral panuveitis, CD8 lymphocytosis, and an absence of parotid involvement.

METHODS

Case series of four HIV-1-infected patients naive to antiretroviral treatment.

RESULTS

Four patients with symptomatic panuveitis are presented. Ocular, systemic, and investigation findings are reported. Recognised causes of panuveitis were excluded. All patients showed a clinical response to steroids and antiretroviral therapy.

CONCLUSIONS

Symptomatic panuveitis may occur in HIV-1-infected individuals with CD8 lymphocytosis in the absence of a recognised cause. These patients have clinical features that resemble diffuse infiltrative lymphocytosis syndrome and may represent a subgroup of this syndrome.

Skeletal muscle involvement in human immunodeficiency virus (HIV)-infected patients in the era of highly active antiretroviral therapy (HAART)

Skeletal muscle involvement can occur at all stages of human immunodeficiency virus (HIV) infection, and may represent the first manifestation of the disease. Myopathies in HIV-infected patients are classified as follows: (1) HIV-associated myopathies and related conditions, including HIV polymyositis, inclusion-body myositis, nemaline myopathy, diffuse infiltrative lymphocytosis syndrome (DILS), HIV-wasting syndrome, vasculitic processes, myasthenic syndromes, and chronic fatigue; (2) muscle complications of antiretroviral therapy, including zidovudine and toxic mitochondrial myopathies related to other nucleoside-analogue reverse-transcriptase inhibitors (NRTIs), HIV-associated lipodystrophy syndrome, and immune restoration syndrome related to highly active antiretroviral therapy (HAART); (3) opportunistic infections and tumor infiltrations of skeletal muscle; and (4) rhabdomyolysis. Introduction of HAART has dramatically modified the natural history of HIV disease by controlling viral replication, but, in turn, lengthening of the survival of HIV-infected individuals has been associated with an increasing prevalence of iatrogenic conditions.

A case of Hodgkin's lymphoma associated with sensory neuropathy

Peripheral neuropathies occur in lymphoma patients. Causes of neuropathy include chemotherapy, opportunistic infections, and the lymphoma itself. We report a patient with lymphoma whose chief complaint was a sensory loss in the hands and feet. Electrophysiologic studies and sural nerve biopsy showed sensory polyneuropathies. We hypothesize that this neuropathy is associated with lymphoma-related ganglionopathy, and among the possible causes, we suspect that a systemic cause such as a paraneoplastic syndrome is the most likely pathogenic etiology. However, further follow-up will be necessary to see whether sensory symptoms change with lymphoma treatment.

The peripheral nerve complications of human immunodeficiency virus (HIV) infection

Peripheral nerve complications occurring in patients with human immunodeficiency virus (HIV) infection are frequent and challenging. This review discusses these various complications according to the degree of advancement of HIV disease. Particular emphasis is placed upon emerging causes of neuropathy found in the context of HIV disease, such as infection with hepatitis C and human T-lymphotropic virus type I, as well as neuropathies related to antiretroviral medications.

HIV-associated neuropathies: role of HIV-1, CMV, and other viruses

The role of the human immunodeficiency virus (HIV) and other viruses in the development of neuropathies associated with HIV infection is controversial. Distal symmetric polyneuropathy (DSP), the most common subtype of HIV-associated neuropathy, is characterized by an abundance of reactive macrophages within the peripheral nerve, but HIV replication is limited to a small percentage of the macrophages. Thus, the pathological destruction may be mediated by pro-inflammatory signals amplified by activated glial elements within the nerve, similar to the proposed mechanism of damage caused by HIV within the central nervous system. In contrast, in mononeuropathy multiplex (MM) and progressive polyneuropathy (PP), cytomegalovirus (CMV) replication in the peripheral nerve is consistently demonstrable, and this replication likely results in direct damage to the infected cells (neurons and glia). The rarest form of HIV-associated neuropathy, the diffuse infiltrative lymphocytosis syndrome (DILS), is characterized by an intense CD8+ T lymphocyte infiltration into the nerve and abundant HIV infection of macrophages. Finally, while other viruses (varicella zoster, herpes simplex) are associated with myelitis in HIV-infected individuals, there is little support for a role for these viruses in HIV-associated neuropathy.

HIV neuropathy: insights in the pathology of HIV peripheral nerve disease

HIV-associated neuropathies (HIV-N) have become the most frequent neurological disorder associated with HIV infection. The most common forms of HIV-N are the distal sensory polyneuropathy (DSP) and antiretroviral toxic neuropathies (ATN), disorders characterized mostly by sensory symptoms that include spontaneous or evoked pain that follow a subacute or chronic course. The main pathological features that characterize DSP and ATN include "dying back" axonal degeneration of long axons in distal regions, loss of unmyelinated fibers, and variable degree of macrophage infiltration in peripheral nerves and dorsal root ganglia. Marked activation of macrophages as well as the effect of pro-inflammatory cytokines appear to be the main immunopathogenic factors in DSP. Interference with DNA synthesis and mitochondrial abnormalities produced by nucleoside antiretrovirals have been hypothesized as pathogenic factors involved in ATN. The use of skin biopsy has become a useful tool in the evaluation of HIV-N. Reduction in fiber density, increased frequency of fiber varicosities and fiber fragmentation are prominent features of skin biopsies from patients with HIV-N. Other forms of HIV-N include acute or chronic inflammatory polyneuropathies, uncommon disorders that may ocur during seroconversion or early stages of HIV infection. Opportunisitic infections, mostly associated with cytomegalovirus or herpes zoster virus infection occur in late stages of AIDS and produce characteristic clinical features such as mononeuritis multiple or radiculopathies.

Epidemiology and clinical features of HIV-1 associated neuropathies

Peripheral neuropathy is common in human immunodeficiency virus type-1 (HIV-1) infection. Peripheral neuropathies complicate all stages of the HIV-1 disease and cause considerable morbidity and disability in HIV-1 infected individuals and acquired immunodeficiency syndrome (AIDS) patients. Whereas symptomatic neuropathies occur in approximately 10% to 15% of HIV-1-infected patients overall, pathologic evidence of peripheral nerve involvement is present in virtually all end-stage AIDS patients. There are 6 major clinical types of HIV-associated neuropathies that are regularly seen in large HIV-1 clinics. Distal sensory polyneuropathy (DSP) is the most common among the HIV-1-associated neuropathies. DSP generally occurs in later stages of HIV-1 infection and it follows an indolent and protracted clinical course. The dominant clinical features in DSP include distal pain, paresthesia and numbness in a typical length-dependent fashion with proximal to distal gradient. Whereas toxic neuropathies--secondary to certain antiretroviral agents--are clinically similar to DSP, their temporal relation to neurotoxic medication helps distinguish them from other HIV-1-associated neuropathies. DSP and toxic neuropathy may coexist in a single patient. Acute and chronic inflammatory demyelinating polyradiculoneuropathies (AIDP and CIDP) produce global limb weakness. AIDP may occur at seroconversion and it can therefore be the initial manifestation of HIV-1 infection. CIDP generally occurs in the mid to late stages of HIV-1 infection. Progressive polyradiculopathy (PP) occurs in patients with advanced immunodeficiency and is generally caused by the opportunist cytomegalovirus (CMV) infection. Mononeuropathy multiplex (MM) in early stages of HIV-1 infection is immune mediated, whereas in advanced AIDS it is caused by the CMV infection. Finally, subclinical autonomic nervous system involvement is common in all stages of HIV-1 infection. Because HIV-1-associated neuropathies are diverse in their etiology and pathogenesis, a precise clinical diagnosis is required to formulate a rational therapeutic intervention.

Neuropathy in HIV infection

Peripheral nerve complications in patients infected with HIV usually result from the virus itself, or are due to some of the antiretroviral drugs (zalcitabine, didanosine or stavudine). It may be difficult to distinguish between these two aetiologies on clinical or neurophysiological criteria. Since they are a significant cause of morbidity, a number of studies have looked at agents used for symptomatic control. More recently, there has been a focus on treatments that improve nerve function, including recombinant human nerve growth factor and the reduction of HIV viral load with antiretroviral drugs.

HIV-associated peripheral neuropathy: epidemiology, pathophysiology and treatment

Peripheral neuropathy is the most frequent neurological complication associated with human immunodeficiency virus type 1 (HIV) infection and advanced acquired immunodeficiency syndrome (AIDS). There are at least 6 patterns of HIV-associated peripheral neuropathy, although these diagnoses are often overlooked or misdiagnosed. Distal symmetrical polyneuropathy (DSP) is the most common form of peripheral neuropathy in HIV infection. DSP occurs mainly in patients with advanced immunosuppression and may also be secondary to the neurotoxicity of several antiretroviral agents. Treatment of painful DSP is primarily symptomatic, while pathogenesis-based therapies are under investigation. Reduction or discontinuation of neurotoxic agents should be considered if possible. Inflammatory demyelinating polyneuropathy (IDP) can present in an acute or chronic form. The acute form may occur at the time of primary HIV infection or seroconversion. Cerebrospinal fluid lymphocytic pleocytosis (10 to 50 cells/mm3) is helpful in the diagnosis of HIV-associated IDP. Treatment consists of immunomodulatory therapy. Progressive polyradiculopathy (PP) most commonly occurs in advanced immunosuppression and usually is caused by cytomegalovirus (CMV) infection. Rapidly progressive flaccid paraparesis, radiating pain and paresthesias, areflexia and sphincter dysfunction are the cardinal clinical features. Rapid diagnosis and treatment with anti-CMV therapy are necessary to prevent irreversible neurological deficits resulting from nerve root necrosis. Mononeuropathy multiplex (MM) that occurs in early HIV infection is characterised by self-limited sensory and motor deficits in the distribution of individual peripheral nerves. In advanced HIV infection, multiple nerves in two or more extremities or cranial nerves are affected. Treatment includes immunomodulation or anti-CMV therapy. Autonomic neuropathy may be caused by central or peripheral nervous system abnormalities. Treatment is supportive with correction of metabolic or toxic causes. Diffuse infiltrative lymphocytosis syndrome (DILS) presents as a Sjögren's-like disorder with CD8 T cell infiltration of multiple organs. Antiretroviral therapy and steroids may be effective treatments.