Phagocytic Dysfunction - Primary Immunodeficiencies

Primary Immunodeficiencies

Primary immunodeficiencies, rare disorders with genetic origins, are seen primarily in infants and young children. To date, more than 95 immunodeficiencies of genetic origin have been identi-fied (Buckley, 2000). Symptoms usually develop early in life after protection from maternal antibodies decreases. Without treat-ment, infants and children with these disorders seldom survive to adulthood. These disorders may involve one or more components of the immune system. Symptoms of immune deficiency diseases are related to the role that the deficient component normally plays (Table 51-1).

PHAGOCYTIC DYSFUNCTION

Pathophysiology

A variety of primary defects of phagocytes may occur; nearly all of them are genetic in origin and affect the innate immune system. In some types of phagocytic disorders, the neutrophils are im-paired so that they cannot exit the circulation and travel to sites of infection. As a result the patient cannot mount a normal inflam-matory response against pathogenic organisms (Lekstrom-Himes Gallin, 2002). In some disorders, the neutrophil count may be very low; in others, it may be very high because the neutrophils re-main in the vascular system.

Clinical Manifestations

Phagocytic cell disorders are manifested by an increased incidence of bacterial and fungal infections due to normally nonpathogenic organisms (Lekstrom-Himes & Gallin, 2002). People with these disorders may also develop fungal infections from Candida or-ganisms and viral infections from herpes simplex or herpes zoster virus. These patients experience recurrent furunculosis, cutaneous abscesses, chronic eczema, bronchitis, pneumonia, chronic otitis media, and sinusitis. In one type of phagocytic disorder, hyper-immunoglobulinemia E (HIE) syndrome, formerly known as Job syndrome, white blood cells cannot produce an inflammatory re-sponse to the skin infections; this results in deep-seated cold ab-scesses that lack the classic signs and symptoms of inflammation (redness, heat, and pain).

While patients with phagocytic cell disorders may be asympto-matic, severe neutropenia may be accompanied by deep and painful mouth ulcers, gingivitis, stomatitis, and cellulitis. Death from overwhelming infection occurs in about 10% of patients with severe neutropenia. Chronic granulomatous disease, another type of primary phagocytic disorder, produces recurrent or persistent infections of the soft tissues, lungs, and other organs; these are re-sistant to aggressive treatment with antibiotics (Lekstrom-Himes & Gallin, 2002).

Assessment and Diagnostic Findings

Diagnosis is based on the history, signs and symptoms, and lab-oratory analysis of the cytocidal (causing the death of cells) activ-ity of the phagocytic cells by the nitroblue tetrazolium reductase test. A history of recurrent infection and fever in a child and occasionally in an adult is an important key to the diagnosis. Failure of an infection to resolve with usual treatment is also an important indicator (Lekstrom-Himes & Gallin, 2002). See Chart 51-1 for a summary of warning signs of primary immunodeficiency disorders.

Medical Management

Because the signs and symptoms of infection are often blunted because of an impaired inflammatory response, early diagnosis and treatment of infectious complications can be lifesaving (Lekstrom-Himes & Gallin, 2002). Management of phagocytic cell disorders includes treating bacterial infections with prophy-lactic antibiotic therapy. Additional treatment for fungal and viral infections is often needed. Granulocyte transfusions, although used, are seldom successful because of the short half-life of the cells. Treatment with granulocyte-macrophage colony-stimulating factor (GM-CSF) or granulocyte colony-stimulating factor (G-CSF) may prove successful because these proteins draw nonlymphoid stem cells from the bone marrow and hasten their maturation.