Neutrophil CD64 versus Neutrophil/Lymphocyte ratio (NLR) as markers predicting in-hospital outcome in acute exacerbation of COPD

Acute exacerbation of COPD is among the most frequent reasons for hospitalisation. Approximately 4% of the general population in the western world is admitted with an acute respiratory disease at least once a year and nearly one fifth of hospital visits is due to acute exacerbation of COPD. Early identifications and management of AE-COPD is an important issue in clinical practice. AE-COPD is accompanied with various worsening respiratory symptoms and deterioration in lung function. Also the frequency and severity of attacks is associated with increased mortality.

During exacerbation, the inflammation in COPD is amplified in comparison with stable periods. The increased level of inflammatory markers is associated with lung function decline. As infection, is the main cause leading to clinical AECOPD, white blood cell counts and ESR are the common markers to show the existence of infection in patients with COPD. Recently, other bio markers are used. Authors have found that the high-affinity Fc receptor-CD64 is expressed by monocytes and only weakly on resting neutrophils. The high-expression of neutrophil CD64 (nCD64) is an early step in the host- immune response to bacterial infection. Studies have shown that the nCD64 might be used as a bio-marker for early-onset sepsis or bacterial infection. However, authors agreed that the value of the nCD64 in COPD prognosis is unknown.

As most of novel bio-markers that identify the severity of acute exacerbation in COPD, are time consuming and expensive, there is a need to use more simple tests. The Neutrophil-lymphocyte ratio is a rapid, easy and cost-effective method derived from routine complete blood count tests in clinical practice. The NLR could be an important marker that assess inflammatory status in patients with COPD and could identify early, acute exacerbation. However, this bio marker has not been widely used in the diagnosis of AECOPD.

The purpose of the present study is: 1- To measure the values of the neutrophil CD64 and NLR in patients with AECOPD and stable COPD, 2- to correlate between nCD64, NLR and the usual routine bio-markers as white blood cell count and erythrocyte sedimentation rate, 3- to investigate the role of nCD64 and NLR as predictors for short term hospital outcome in this group.

Inclusion Criteria:

• patients diagnosed as AECOPD and stable COPD ( random selection by 1:1 cross over). A diagnosis of COPD was made by a clinical history, examination and spirometer (forced expiratory volume in 1st second/forced vital capacity (FEV1/FVC)ratio of <0.7). The severity of COPD was graded according to the Global Initiative for Chronic Obstructive Lung Disease guidelines.

Exclusion Criteria:

• history of current respiratory disorders other than COPD, malignancy, systemic auto-immune disorders, recent surgery and severe endocrine, hepatic or renal diseases. Patients with pneumonia, cardiovascular and metabolic diseases

The exacerbation of COPD is defined as the patient being diagnosed with COPD with two or more of the following three symptoms of exacerbations: new or worsening cough, worsened dyspnea, and worsened sputum volume and/or change in its color.