[Sarcoidosis with hematologic involvement and hypogammaglobulinemia]

Hematological involvement in sarcoidosis: from cytopenias to lymphoma

INTRODUCTION

We present an updated overview of the hematological involvementassociated with sarcoidosis, including a management approach forcytopenias and revisiting the association with hematologicalmalignancies.

AREAS COVERED

Theetiology of cytopenias in sarcoidosis can be attributed to two majoretiopathogenic mechanisms: infiltration of hematopoietic organs suchas the spleen and bone marrow, and autoimmune-mediated cytopenias.With respect to the association with hematological malignancies, itrequires careful evaluation of patients from a chronologicalperspective. Patients must be classified into one of three pathogenicscenarios, including preexisting hematological malignancies,synchronous development of malignancy and sarcoidosis due to commonpredisposing factors, or sarcoidosis as a predisposing factor formalignancies.

EXPERT OPINION

The association between sarcoidosis and hematologic involvement isbest understood as a pathogenic continuum, with cytopenias andhematologic neoplasms intertwined due to various etiopathogenicmechanisms. These mechanisms include sarcoid infiltration ofhematopoietic organs, common predisposing immunogenetics for thedevelopment of autoimmune cytopenias and malignancies, and anincreased risk of neoplasm development in patients with autoimmunecytopenias. Collaboration among the main specialties involved in theclinical management of these patients is crucial for an earlymonitoring and management.

[Granulomatous disease in common variable immunodeficiency]

PURPOSE

Common variable immunodeficiency (CVID), defined by defective production of immunoglobulins, is the most common primary immunodeficiency in adulthood requiring a medical follow-up. Repeated bacterial infections and/or autoimmune manifestations and/or benign lymphoproliferation (including follicular hyperplasia and/or granulomatous disease) are the hallmark of the disease. This review aims at describing recent advances in the understanding and treatment of granulomatous disease in CVID.

CURRENT KNOWLEDGE AND KEY POINTS

Clinical features of granulomatous disease in CVID can mimic sarcoidosis, remarkable by the low levels of circulating immunoglobulins. Granulomas may be found in several organs in a single patient, and the main features are pulmonary, lymphoid, cutaneous, hepatic or splenic. The features of CVID is remarkable by the high frequency of autoimmune diseases complicating the immunodeficiency. Some immunological abnormalities have been described in such patients, including lymphopenia, decreased T-cells proliferations to mitogens and antigens. Rare polymorphisms in the gene encoding TNFalpha (Tumor Necrosis Factor) have been identified in CVID patients with granulomatous disease.

FUTURE PROSPECTS AND PROJECTS

The evolution of the disease is severe, particularly when the lung is involved. Treatment consists in immunoglobulins substitution, immunosuppressive agents (corticosteroids, cyclophosphamide) and anti-TNFalpha antibodies. These treatments are difficult to manage in such immunocompromised patients.