IgG4-Related Disease and Innate Immunity

Diagnosis of inflammatory bowel disease according to human IgG4 and possibilities of evaluating efficacy of the therapy

Taking into account the progress of understanding diagnosis, course prognosis, evaluation of effectiveness of therapy of inflammatory bowel disease and also differentiation diagnosis between its main forms – ulcerative colitis and Crohn’s disease, the search for efficient non-invasive markers for solving those issues is extremely relevant. The patients were divided into groups depending on nosology and severity of the course of the disease. All the patients had undergone endoscopic study for diagnosis verification and biopsy samples were taken for further detection of tissue IgG4 using the immunohistochemical method. Also, we determined concentration of serum IgG4. Increase in IgG4content in blood serum was determined in 54.0% of the cases of inflammatory bowel disease. Concentration of IgG4 in patients suffering ulcerative colitis was higher (by 2.31 and 2.46 times) compared with its level in the control group and patients with Crohn’s disease, respectively. We found relationships between the concentration of serum IgG4 and the activity of the disease. In patients with ulcerative colitis, increased tissue IgG4 was found more often than in patients with Crohn’s disease (by 2.77 times, Р < 0.05). We determined the relationship between tissue IgG4 and histological activity. Simultaneous increase in serum IgG4 and presence of tissue IgG4 during ulcerative colitis were more frequent than during Crohn’s disease (by 2.66 times). In all examined groups of patients, we determined decrease in serum IgG4 content (by 1.66 times) after treatment. Concentration of serum IgG4 and positive tissue IgG4 in ulcerative colitis patients exceeded such in Crohn’s disease patients, which may be used for differentiation diagnosis between those disease types. We determined dependence of IgG4 concentration on severity and duration of the disease, which could be used as a prognostic marker. Decrease in IgG4 content in blood serum against the background of the therapy shows that this indicator could be used as a marker of treatment efficacy. Perspectives of further studies are as follows: parameters of concentration of serum IgG4 and presence of tissue IgG4 could be used as diagnostic and prognostic biomarkers and be introduced to practice for differentiation diagnosis between ulcerative colitis and Crohn’s disease, and could be used as prognostic marker of severity of the disease and therapy efficacy.

Pathophysiology of the Different Clinical Phenotypes of Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP)

Chronic inflammatory demyelinating polyneuropathy (CIDP) is the most common form of autoimmune polyneuropathy. It is a chronic disease and may be monophasic, progressive or recurrent with exacerbations and incomplete remissions, causing accumulating disability. In recent years, there has been rapid progress in understanding the background of CIDP, which allowed us to distinguish specific phenotypes of this disease. This in turn allowed us to better understand the mechanism of response or non-response to various forms of therapy. On the basis of a review of the relevant literature, the authors present the current state of knowledge concerning the pathophysiology of the different clinical phenotypes of CIDP as well as ongoing research in this field, with reference to key points of immune-mediated processes involved in the background of CIDP.

Diagnostic and treatment workup for IgG4-related disease

INTRODUCTION

IgG4-Related Disease is a newly recognized condition which is increasingly diagnosed by practitioners due to improvement in clinical awareness. Men and women have been found to be affected by this disease in various organs, more commonly with involvement of the salivary and lacrimal glands as well as pancreas and liver. Areas covered: The diagnosis and management of this condition remain challenging as biomarkers and therapies are being investigated. Hallmark features on histology are still the gold standard for confirmation of diagnosis, whereas serum IgG4 level has been shown to be neither necessary nor sufficient for the diagnosis. Glucocorticoids remain the most effective initial management for this condition while there are limited clinical trials on the effectiveness of maintenance therapy. Expert commentary: This review serves as an update on approaches for diagnosis and management of IgG4-RD. Most of the known data in this field comes from retrospective cohort studies and expert consensus guidelines but new ongoing prospective studies, clinical trials and better understanding of the pathogenesis of this condition are promising.

Recent advances in understanding and managing IgG4-related disease

IgG4-related disease was only recently discovered, so its description, management, and new discoveries related to its etiology are rapidly evolving. Because IgG4 itself is a unique antibody which is intimately related to the diagnosis of the disease, the role of plasmablasts in the pathophysiology remains an active area of discussion. Recent studies have uncovered a possible role for CD4-positive cytotoxic T lymphocytes, T follicular helper cells, and M2 macrophages. The clinical presentation is variable and can be vague, as this disease affects many organs and new presentations are continuing to be described. The diagnosis depends on clinical and histopathological assessment. The mainstay of treatment is with glucocorticoids, but rituximab has recently shown promise. Monitoring disease activity using imaging modalities (including positron emission tomography) and serum markers is imperative, as relapses are common. IgG4-related disease spans many medical disciplines but is a treatable condition with which all clinicians should be familiar.