The place of immunotherapy in the management of HCV-induced vasculitis: an update

Current perspectives on the diagnosis, assessment, and management of vasculitic neuropathy

INTRODUCTION

Vasculitic neuropathy can present associated with both primary and secondary systemic vasculitis as a result from underlying diseases such as rheumatic diseases and infections, Moreover, confined vasculitis in the peripheral nervous system may be present. Thus, the diagnosis and management of vasculitic neuropathy require multidisciplinary approaches.

AREAS COVERED

Current views as well as relevant clinical research on the diagnosis, assessment, and management of vasculitic neuropathy are reviewed to suggest appropriate treatment strategies. We searched PubMed and Google Scholar for reports published between July 2017 and July 2022.

EXPERT OPINION

For the treatment of vasculitic neuropathy, determining the causative primary disease is important and often requires diagnosis by tissue biopsy. Due to the scarce research on the treatment of vasculitic neuropathy, treatment is empirically based on findings from studies of systemic vasculitides involving other organs, particularly antineutrophil cytoplasmic antibody-associated vasculitis. In addition to conventional glucocorticoids and immunosuppressive agents, complement-targeted therapy, anti-B-cell therapy, and disease-specific molecular targeted therapies have recently gained relevance. Future research is needed to develop new patient-specific therapeutic options.

[Peripheral nervous system lesion in systemic vasculitis - issues of diagnosis and treatment]

Vasculitis is a clinically diverse group of diseases with histopathological signs of blood vessel inflammation, which contributes to vascular damage and ischemic damage to the affected tissues. Vasculitic neuropathy is a common complication of the primary systemic vasculitides, such as polyartertis nodosa and antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis, systemic diseases of the connective tissue - systemic lupus erythematosus and Sjogren syndrome, vasculitis associated with infection, most often viral hepatitis C and B and non - systemic vasculitis neuropathy. Vessels of medium and small caliber are involved in the pathological process in these diseases. With all vasculitis, except for those caused by the direct effect of the infectious trigger on the blood vessel walls, the main pathogenetic mechanism is an autoimmune process with the development of vasa nervorum vasculitis - small arteries and vessels that supply peripheral nerves, and the outcome - nerve ischemia. The classic clinical presentation is an acute or subacute painful multifocal neuropathy that has a predilection for the lower extremities, affects two or more named nerves, and progresses in a step wise manner. However, vasculitic neuropathy can manifest in a variety of ways, including asymmetric polyneuropathies and distal symmetric sensory neuropathies, and it also can be slowly progressive, particularly in cases of nonsystemic vasculitic neuropathy (NSVN), a form of vasculitis that clinically remains restricted to peripheral nerves. Nerve biopsy can help establish the diagnosis of a systemic vasculitis, particularly when other organ involvement is not clinically apparent, and is required for diagnosis of NSVN. Neuropathy due to systemic vasculitis should be treated in accordance with the recommendations for the treatment of the underlying disease. In NSVH, the main medicine of choice are glucocrticoids, and in severe/progressive cases, pulse therapy with cyclophosphamide.

Oral anti-CD3 immunotherapy for HCV-nonresponders is safe, promotes regulatory T cells and decreases viral load and liver enzyme levels: results of a phase-2a placebo-controlled trial

Orally administered anti-CD3 antibodies are biologically active in the gut through induction of regulatory T cells, exert an immune-modulatory effect, and alleviate insulin resistance and liver damage in patients with NASH.

AIMS

To determine the safety of oral anti-CD3 monoclonal antibody (MAb) immunotherapy in chronic HCV patients with associated immune dysfunction.

METHODS

Four groups (n = 9) of chronic HCV patients who were nonresponders to interferon plus ribavirin therapy received oral placebo (group A) or anti-CD3 MAb at one of three dosage levels for 30 days. Patients were followed for safety parameters and serum levels of liver enzymes, virus, cytokines and regulatory T cells.

RESULTS

Oral anti-CD3 immunotherapy was safe and well tolerated; no treatment-related adverse events were noted. The following improvements were noted relative to pretreatment levels: HCV viral load and AST and ALT levels decreased in the low- and high-dose groups following 30 days of therapy. In two of the treated groups, an increase in regulatory T cells (CD4(+) CD25(+) ) was noted. The positive effects were somewhat more apparent in subjects with initially elevated liver enzyme levels.

CONCLUSIONS

Oral anti-CD3 MAb immunotherapy for nonresponder HCV patients was safe and well tolerated. Trends and statistically significant improvements were observed as reductions in viral load and liver enzyme levels, along with an increase in regulatory T-cell levels. These data support a role for the immune system in the pathogenesis of HCV infection and suggest that this immunotherapy is worthy of evaluation in combination with HCV antiviral drugs.

Diagnosis and therapeutic options for peripheral vasculitic neuropathy

Vasculitis can affect the peripheral nervous system alone (nonsystemic vasculitic neuropathy) or can be a part of primary or secondary systemic vasculitis. In cases of pre-existing systemic vasculitis, the diagnosis can easily be made, whereas suspected vasculitic neuropathy as initial or only manifestation of vasculitis requires careful clinical, neurophysiological, laboratory and histopathological workout. The typical clinical syndrome is mononeuropathia multiplex or asymmetric neuropathy, but distal-symmetric neuropathy can frequently be seen. Standard treatments include steroids, azathioprine, methotrexate and cyclophosphamide. More recently the B-cell antibody rituximab and intravenous immunoglobulins have shown to be effective in some vasculitic neuropathy types.