What is the clinical significance of a patient's laboratory results showing leukocytosis (White Blood Cell count 11.4 K/uL), normal red blood cell (RBC) count (5.01 M/uL), elevated hemoglobin (16.6 g/dL), normal hematocrit (47.2%), normal mean corpuscular volume (MCV) (94 fL), elevated mean corpuscular hemoglobin (MCH) (33.1 pg), normal mean corpuscular hemoglobin concentration (MCHC) (35 g/dL), normal platelet count (216 K/uL), normal red cell distribution width (RDW) (11.8%), normal mean platelet volume (MPV) (9.9 fL), and elevated neutrophil count (7.8 K/uL)?

From the Guidelines

The elevated neutrophil count of 7.8 K/uL suggests a possible bacterial infection, and according to the most recent and highest quality study 1, a careful assessment for bacterial infection is warranted in the presence of an elevated WBC count or left shift. The blood test results show a few abnormal values that require attention. The hemoglobin level is slightly elevated at 16.6 g/dL, and the MCH is also elevated at 33.1 pg. However, the most notable finding is the elevated neutrophil count, which suggests an active immune response, typically seen with bacterial infections, inflammation, or physical stress. The study by the Infectious Diseases Society of America 1 recommends that a CBC count, including peripheral WBC and differential cell counts, should be performed for all suspected infections, and the presence of an elevated WBC count or left shift warrants a careful assessment for bacterial infection. Some key points to consider include:

• The elevated neutrophil count has a likelihood ratio of 3.7 for detecting documented bacterial infection, as shown in the study 1.
• The presence of an elevated WBC count or left shift is a strong indicator of bacterial infection, even in the absence of fever, as stated in the study 1.
• The study 1 recommends that additional diagnostic tests may not be indicated in the absence of fever, leukocytosis, or specific clinical manifestations of a focal infection, due to the low potential yield. Based on the evidence, it is essential to follow up with a healthcare provider to discuss these results, particularly the elevated neutrophil count, and to determine the underlying cause of the abnormal findings. Staying well-hydrated and reporting any symptoms like fever, pain, or unusual fatigue would be crucial in this situation. No immediate medication is needed based solely on these results, but the doctor may recommend additional testing or treatment depending on the clinical symptoms and medical history.

From the Research

Blood Test Results

The provided blood test results show the following values:

• WBC (White Blood Cell count): 11.4 K/uL, which is within the normal range of 4.5 - 11.5 K/uL
• RBC (Red Blood Cell count): 5.01 M/uL, which is within the normal range of 4.50 - 5.30 M/uL
• Hemoglobin: 16.6 g/dL, which is slightly above the normal range of 13.0 - 16.0 g/dL
• Hematocrit: 47.2%, which is within the normal range of 40.0 - 57.0%
• MCV (Mean Corpuscular Volume): 94 fL, which is within the normal range of 80 - 99 fL
• MCH (Mean Corpuscular Hemoglobin): 33.1 pg, which is slightly above the normal range of 27.0 - 31.0 pg
• MCHC (Mean Corpuscular Hemoglobin Concentration): 35 g/dL, which is within the normal range of 32 - 36 g/dL
• Platelets: 216 K/uL, which is within the normal range of 150 - 450 K/uL
• RDW (Red Cell Distribution Width): 11.8%, which is within the normal range of 11.5 - 15.5%
• MPV (Mean Platelet Volume): 9.9 fL, which is within the normal range of 7.4 - 10.4 fL
• Neutrophils: 7.8 K/uL, which is above the normal range of 1.4 - 6.5 K/uL
• Lymphocytes: 2.7 K/uL, which is within the normal range of 1.2 - 3.4 K/uL

Inflammatory Response

The elevated neutrophil count may indicate an inflammatory response, as stated in the study 2. This study suggests that elevated leukocyte count, including neutrophil count, may be a harbinger of increased systemic inflammation and subclinical disease.

Immune Response

The immune response to infection is a complex process, as described in the study 3. This study explains that the inflammatory and immune response to infection is targeted at removing foreign invaders from the body, and that the severity of the infection and the body's response depend on various factors, including the intactness of barrier defenses, immune competence of the host, and virulence of the invading organism.

Leukocyte Count

The study 2 also mentions that leukocyte count is a strong and reliable inflammatory marker that can reflect the rate of aging and predict long-term survival in the elderly. Additionally, the study 4 discusses the role of pro-inflammatory and anti-inflammatory interleukins in infectious diseases, highlighting their importance in regulating immune responses.

Sepsis and Inflammatory Response

The study 5 discusses the pathophysiology of sepsis secondary to bacterial infection and reviews the current recommended management strategies. The study 6 also explores the mechanisms of phagocytosis and the inflammatory response, highlighting the importance of macrophages in detecting infectious organisms and orchestrating an appropriate host response.

Key Findings

• Elevated neutrophil count may indicate an inflammatory response 2
• Leukocyte count is a strong and reliable inflammatory marker 2
• Immune response to infection is a complex process 3
• Pro-inflammatory and anti-inflammatory interleukins play a crucial role in regulating immune responses 4
• Sepsis secondary to bacterial infection remains a significant cause of morbidity and mortality globally 5