Segmented neutrophils

Evaluation of segmented neutrophils in a baseline complete blood count

In routine clinical practice, the count of segmented neutrophils is evaluated as a percentage. Let us examine a typical complete blood count profile demonstrating a moderate left shift of the leukocyte formula:

• Leukocytes (WBC): 6.0 × 10³/mm³.
• Segmented neutrophils (segs): 46%.
• Band neutrophils (bands): 10% (this specific parameter indicates a left shift).
• Other populations: lymphocytes comprise 36%, monocytes — 8%.
• Special notes: anioinophilia is observed (eosinophils equal 0%).

This clinical example also notes a hemoglobin (Hb) level of 110 g/L and an erythrocyte sedimentation rate (ESR) of 8 mm/h. This picture demonstrates that even with a normal total leukocyte count, a redistribution of the cell pool can occur within the differential, featuring an increase in immature band forms.

Changes in systemic juvenile idiopathic arthritis

A completely different pattern of neutrophil distribution is observed in systemic juvenile idiopathic arthritis (JIA). This pathology is characterized by a pronounced systemic inflammatory response syndrome, manifested by specific alterations in laboratory tests.

Key blood changes include:

• Development of marked neutrophilic leukocytosis (hyperleukocytosis exceeding 20 × 10^9/L).
• Appearance of a sharp left shift in the leukocyte differential, accompanied by a persistently high percentage of both segmented neutrophils and their precursors — band cells.
• Significant acceleration of ESR, reaching 60 mm/h or more.

It is important to note that such a pronounced neutrophilic response occurs against the background of negative specific rheumatological tests (including rheumatoid factor and antinuclear factor) and negative blood cultures. At the same time, the biochemical blood test shows a sharply positive C-reactive protein (CRP +++), and the immunogram reveals an elevation in serum immunoglobulins (IgG, IgA, IgM).

Neutrophils in severe multiorgan dysfunction

Of particular interest is the evaluation of segmented neutrophils in patients with critical metabolic disorders. In one of the analyzed clinical cases, the total leukocyte count remained within the normal range (7.0 × 10^9/L), yet the differential showed a catastrophic shift.

The proportion of band cells reached 45%, and segmented neutrophils accounted for 43%. Lymphocytes and monocytes accounted for only 7% and 5%, respectively.

This sharp cellular imbalance was accompanied by a complex of life-threatening disorders, including:

1. Severe anemia: erythrocytes 3.56 × 10^12/L, hemoglobin 80 g/L, hematocrit 31%, ESR accelerated to 38 mm/h.
2. Acute kidney injury (AKI): urea 32.5 mmol/L, creatinine 401 µmol/L, pronounced proteinuria (urine protein 3.0 g/L) and hematuria (erythrocytes 40–50 per HPF).
3. Critical electrolyte imbalance: life-threatening hyperkalemia (K+ 9.0 mmol/L) and severe hyponatremia (Na+ 120 mmol/L).
4. Decompensated acidosis: pH 7.33, marked hypoxemia (pO2 48.8 mmHg, SatO2 60.6%), hypocapnia (pCO2 30.8 mmHg) and BE -12.5.
5. Cytolysis syndrome and liver injury: hypoalbuminemia (albumin 28.0 g/L), hyperbilirubinemia (direct bilirubin 50 µmol/L, indirect 35 µmol/L), AST 60 IU/L, ALT 70 IU/L. Malaria parasites were not detected.

Class and exam questions

What else to study on this topic

• Clinical significance and markers of acute kidney injury (creatinine, urea)
• Interpretation of acid-base balance and blood gas parameters
• Life-threatening electrolyte balance disorders: hyperkalemia and hyponatremia
• Differential diagnosis of systemic JIA
• Laboratory signs of hepatic cytolysis syndrome

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.