Chronic Idiopathic Neutrophilia: Experience and Recommendations

Laboratory Findings in Children with Excess Body Weight in Romania

Background and Objectives: Childhood obesity has been increasing at a worrisome pace and emerging as a non-infectious pandemic in the pediatric population in recent years. Raising awareness on this problem is of utmost importance, in order to take action to control body weight from an early age. Materials and Methods: We performed a retrospective study among overweight or obese children evaluated on an outpatient basis in the Department of Pediatric Endocrinology of a tertiary care hospital in Bucharest Romania in 2021 in order to identify laboratory changes occurring according to age and sex. Results: A total of 268 children were included in the analysis, with a median age of 10.9 years (IQR: 8.3, 13.3 years); 61.8% were obese and 38.2% overweight. We identified a subclinical pro-inflammatory status characterized by increased neutrophil count (12.7%) and increased C-reactive protein (16.4%). Biochemically, we identified the highest increases for uric acid (35.4%). More than half of the children included in the study had dyslipidemia-specific changes: high low-density lipoprotein cholesterol (LDL) (50.0%), low high-density lipoprotein cholesterol (HDL) (58.9%) and increased triglyceride levels (12.7%), especially children with a body mass-index (BMI) percentile above 95%. Increased thyroid stimulating hormone (TSH) was identified in 20.3% and low thyroxine (T4) level in 13.4%, especially in females. Conclusions: Early measures to control excess body weight are needed since preventing obesity is easier than treating it. However, this is often difficult to do in our country because parents frequently do not recognize the problem until it is advanced. Furthermore, doctors are not always adequately prepared and sometimes they do not have the support of the health systems to provide children in need with the adequate care. Educational strategies and awareness of issue should be revisited in current post-pandemic context that facilitates increase of obesity prevalence in children. Increase of efficient communication could be achieved by pointing to these objective findings.

Neutrophils Actively Contribute to Obesity-Associated Inflammation and Pathological Complications

Obesity is characterized by an increase in body weight associated with an exaggerated enlargement of the adipose tissue. Obesity has serious negative effects because it is associated with multiple pathological complications such as type 2 diabetes mellitus, cardiovascular diseases, cancer, and COVID-19. Nowadays, 39% of the world population is obese or overweight, making obesity the 21st century epidemic. Obesity is also characterized by a mild, chronic, systemic inflammation. Accumulation of fat in adipose tissue causes stress and malfunction of adipocytes, which then initiate inflammation. Next, adipose tissue is infiltrated by cells of the innate immune system. Recently, it has become evident that neutrophils, the most abundant leukocytes in blood, are the first immune cells infiltrating the adipose tissue. Neutrophils then get activated and release inflammatory factors that recruit macrophages and other immune cells. These immune cells, in turn, perpetuate the inflammation state by producing cytokines and chemokines that can reach other parts of the body, creating a systemic inflammatory condition. In this review, we described the recent findings on the role of neutrophils during obesity and the initiation of inflammation. In addition, we discuss the involvement of neutrophils in the generation of obesity-related complications using diabetes as a prime example.

CIN or not: An approach to the evaluation and management of chronic idiopathic neutrophilia

Neutrophilia refers to an increase in the number of circulating neutrophils in the peripheral blood. Some common etiologies include infection, inflammatory conditions, myeloproliferative disorders, malignancies, endocrinopathies, drugs, and anemia. Rare disorders such as leukocyte adhesion deficiency can also cause neutrophilia. In many cases, there is an elevation of neutrophil count that persists for months or even years with no clear underlying cause in an otherwise asymptomatic patient. This is referred to as chronic idiopathic neutrophilia (CIN). Despite being a condition encountered by many physicians, there is a paucity of literature addressing CIN. Certain conditions such as stress, exercise, smoking, obesity, and obstructive sleep apnea have been associated with CIN and may provide explanations for neutrophilia previously thought to be idiopathic. Herein, we present a review of the literature on CIN and propose a systematic approach to this commonly encountered clinical condition.

Persistent neutrophilia is a marker for an increased risk of venous thrombosis

In patients with cancer and myeloproliferative disorders, leukocytosis has been associated with an increased venous thromboembolic (VTE) risk. Our goal was to determine whether persistent neutrophilia (PN), not associated with known causes such as malignancies, infections or steroids, is independently associated with VTE. All adult patients with >3 outpatient complete blood counts (CBCs) within 3 years were included. PN was defined as having an absolute neutrophil count >95 % (>2SD) of the population (≥7.8 × 10(9)/L) on at least three CBCs, at least 2 months apart. Separate analyses for neutrophil counts ≥9 × 10(9)/L and ≥10 × 10(9)/L were also performed. Blood counts from inpatients were excluded. Primary outcome was diagnosis of VTE, as determined by ICD-9 codes. Odds ratios were adjusted for diabetes, smoking, obesity, gender, and age. Charlson score was utilized as a morbidity measure. Data on 43,538 outpatients were collected. Although there was no association of VTE with neutrophil counts ≥7.8 × 10(9)/L, patients with ≥9.0 × 10(9)/L neutrophils were twice as likely to be diagnosed with VTE compared to those with normal neutrophil counts (OR 2.0, 95 % CI 1.3, 3.1; p = 0.003). Patients with neutrophil counts ≥10.0 × 10(9)/L were at an even higher risk (OR 2.3, 95 % CI 1.2, 4.8; p = 0.019). Charlson scores significantly modified this risk when incorporated into analysis. Elevated neutrophil counts are associated with an increased risk of venous thrombosis even when they are not due to cancer, infection or steroids. In patients with significant comorbidities, neutrophilia may be a marker of VTE risk.

Chronic idiopathic neutrophilia in two twins

Neutrophilia in adults refers to an alteration in the total number of blood neutrophils that is in excess of about 7500 cells/μL. This definition is restrictive in childhood as neutrophil count is age-dependent. Chronic Idiopathic Neutrophilia (CIN) refers to a condition that persists for many years in individuals who appear otherwise healthy. CIN is rarely mentioned in scientific literature and in academic books of hematology; only few words are dedicated to this topic. We report a case study of two twins with CIN followed from the first year of life to 24 years of age. To the best of our knowledge this is the first case report of two twins with CIN followed through a long period of time. We believe that our observation may contribute to better understand and characterize this hematologic abnormality.

Chronic idiopathic neutrophilia in a smoker, relieved after smoking cessation with the use of electronic cigarette: a case report

INTRODUCTION

Smoking is a major risk factor for a variety of diseases. Electronic cigarettes are battery-operated devices that deliver nicotine to the lungs by evaporation of a liquid. Chronic idiopathic neutrophilia is a condition characterized by elevated white blood cell and neutrophil counts without any underlying disease; smoking has been implicated as a potential cause.

CASE PRESENTATION

A male Caucasian patient, born in 1977, presented in September 2005 with asymptomatic elevation of white blood cell and neutrophil count, and mildly-elevated C-reactive protein levels. He was a smoker since 1996 and was treated with 20 mg/day of simvastatin since 2003 due to hyperlipidemia. Clinical examination, and laboratory and imaging investigations ruled out any infectious, haematological, rheumatological, or endocrine conditions. He was followed-up regularly and was advised to stop smoking. He had 2 unsuccessful attempts to quit smoking; one was unassisted and the second was performed with the use of both varenicline and nicotine replacement therapy (patches). During the subsequent 6.5 years, his leukocyte and C-reactive protein levels were repeatedly elevated; the condition was consistent with chronic idiopathic neutrophilia. In February 2012, he started using electronic cigarettes and he managed to quit smoking within 10 days. After 6 months, laboratory examination showed normalized leukocyte count and C-reactive protein levels, confirmed immediately by a second laboratory and by repeated tests after 1 and 2 months.

CONCLUSION

Smoking cessation with the use of electronic cigarette led to reversal of chronic idiopathic neutrophilia. The daily use of electronic cigarette may help preserve the beneficial effects of smoking cessation.

Why does my patient have leukocytosis?

Leukocytosis is one of the most common laboratory abnormalities in medicine, and one of the most frequent reasons for hematologic consultation. Effective evaluation of leukocytosis requires an attentive history, careful physical examination, meticulous review of the complete blood count and peripheral blood smear, judicious application of laboratory and radiologic testing, and thoughtful analysis. Definitive diagnosis may require bone marrow aspiration and biopsy, imaging studies, and specialized molecular tests. The differential diagnosis of leukocytosis includes physiologic responses to a broad range of infectious and inflammatory processes, as well as numerous primary hematologic disorders such as leukemias, lymphomas, and myeloproliferative neoplasms.