Chronic Benign Neutropenia - Types, Symptoms, Diagnosis, and Management

Introduction

Chronic benign neutropenia, also called autoimmune neutropenia (AIN) of infancy, occurs in infants and children, usually in the first year of life. This is a benign condition and presents especially as mild infections in children. It is induced due to specific neutrophil antibodies that cause peripheral destruction of neutrophils. Careful evaluation of the condition is required to avoid the misdiagnosis of leukemia. It is reported that spontaneous regression occurs within five years of age.

What Is Neutropenia?

White blood cells (WBCs) are blood cells in the human body and function as part of the immune system. It protects the body against infection and protects it from harmful bacteria, viruses, and other foreign pathogens. It is the bone marrow that produces these white blood cells. They are divided into five types, each playing a distinct role in the immune system.

1. Neutrophils.

2. Lymphocytes.

3. Monocytes.

4. Basophils.

5. Eosinophils.

White blood cells are primarily comprised of neutrophils. They are considered the initial line of defense of the immune system. When the body is infected or another source of inflammation is present, specific molecules alert mature neutrophils, leaving the bone marrow and moving through the circulation to the injured place. When a person is sick or injured, the number of neutrophils in their blood increases to assist in healing. However, if an individual has a long-term infection, cancer, an autoimmune illness, or is on specific drugs, the number of neutrophils may drop.

A low number of neutrophils denotes neutropenia. As a result, neutropenia can increase the body's chance of infection. Even typical germs from the mouth and digestive tract can cause considerable sickness when neutropenia is severe. When a pathogen, such as bacteria, enters the body, there are low neutrophils to destroy it. Therefore, the lower absolute neutrophil count will increase the risk of infection.

What Is Meant by Chronic Benign Neutropenia?

In 1941, Hotz and Fanconi first expressed the term 'chronic benign neutropenia' in young children. Chronic benign neutropenia or autoimmune neutropenia (AIN) of infancy is a clinical condition characterized by lowered count of neutrophils which can lead to defects in cell-mediated or humoral immunity. It belongs to heterogeneous disorder. It can present itself individually or be associated with various other hematopoietic or blood system disorders. No specific diagnostic tests are available for this condition, diagnosed by the exclusion method. There are two major types of chronic benign neutropenia or autoimmune neutropenia, and those types are mentioned below,

Primary: It is typically seen in children, especially between 6 and 12 months. The pathophysiology can be associated with antibodies against presenting neutrophil antigens, like human neutrophil antigen 1 (HNA1) and human neutrophil antigen 2 (HNA2). It is a self-limiting condition, and most children recover with normal neutrophil counts within two years. The patients can usually be treated with antibiotic therapy and do not require further intervention.

Secondary: It is observed in adults and usually in people with systemic autoimmune diseases. The cause of this type is heterogeneous in nature, and the main aim of the therapy is to minimize the morbidity and mortality related to serious conditions. Also, the focus is on completing the management of the underlying autoimmune condition.

Drug-Induced Agranulocytosis: It is an acute type of immune neutropenia. It is an idiosyncratic immune reaction seen in patients with profound neutropenia.

What Are the Signs and Symptoms of Chronic Benign Neutropenia?

Neutropenia does not induce symptoms. However, some people may experience additional symptoms due to the infection or the underlying situation leading to neutropenia.

There are several signs and symptoms of neutropenia, which may include the following,

• Fever.

• Pneumonia.

• Infections of the sinuses.

• Ear infection such as otitis media.

• Gum inflammation or gingivitis.

• Abscesses (collections of pus) on the skin.

• Difficult in wound healing.

• Fatigue or extreme tiredness.

• Swollen lymph nodes.

• Sweating or chills.

• A toothache.

• Sore throat.

• Coughing and lack of breath.

• Mouth ulcers or ulcers around the anus.

• Infection-related pain, edema, and rash.

• Diarrhea.

• Loss of appetite.

• Pain during urination or burning sensation and other urinary symptoms.

• Patients may have a fever, rash, and enlarged lymph nodes when medicines cause neutropenia.

Severe congenital neutropenia can induce life-threatening symptoms and bacterial infections. These infections can spread throughout the skin and digestive and respiratory systems.

How Is Chronic Benign Neutropenia Diagnosed?

The diagnosis is mainly made with the answers to the questions related to the symptoms, personal history, and medical issues. A physical examination was done, and certain laboratory tests were done to evaluate and confirm the diagnosis and treatment.

• Complete Blood Count - Complete blood count (CBC) with differential counts of various cells is estimated. It will help in the confirmation of the diagnosis.

• Folate and B12 count - Folate and B12 estimation to rule out neutropenia associated with nutritional deficiencies.

• Bone Marrow Aspiration and Core Biopsy to detect causes of neutropenia like lymphoproliferative neoplasm, myelodysplastic syndrome, or leukemia. It is also advisable to include cytogenetics and flow cytometry in the evaluation.

• Flow Cytometry.

• Antineutrophil Antibody Studies are rarely used.

How Is Chronic Benign Neutropenia Managed?

Some preventive measures can be followed to manage the symptoms of neutropenia. Some of the preventive measures are mentioned below,

• Regular teeth brushing and flossing.

• Maintaining good oral hygiene.

• Frequent hand washing.

• Having immunizations.

• Avoid raw fruits, vegetables, cereals, nuts, honey, unpasteurized dairy products, and undercooked meat.

• Regular exercise.

• Avoid any unhealthy habits.

• Never stroll around barefoot.

• Drinking plenty of water and hydrating dry skin.

• Use gloves while working with chemicals.

• Limiting sun exposure.

• Wear a hospital mask to protect from pathogens in the air.

Conclusion

Chronic benign neutropenia, also called autoimmune neutropenia of infancy, is a benign condition, and the treatment lies in diagnosing the underlying condition or causative factors. It causes mild infections for which antibiotics can be prescribed to manage the signs and symptoms. However, autoimmune neutropenia does not require any severe medical or surgical therapy. Nevertheless, regular monitoring and follow-ups are mandatory.