Which of the following is the predominant cell type seen in the cerebrospinal fluid of a patient suffering from tubercular meningitis?

Appeared in: BTSC Staff Nurse 31 July-2025

Explanation

Tubercular (TB) meningitis is a form of chronic meningitis caused by Mycobacterium tuberculosis.
The body's immune response to this chronic infection is primarily cell-mediated, leading to a predominance of lymphocytes in the cerebrospinal fluid (CSF).
This lymphocytic pleocytosis (increased cell count) is a hallmark finding, often accompanied by low glucose and high protein levels in the CSF.
While neutrophils may be present in the initial few days of the infection, lymphocytes rapidly become the dominant cell type as the disease progresses.

Option B: Eosinophilic pleocytosis (increased eosinophils) is not a feature of tubercular meningitis. It is typically associated with parasitic infections, certain fungal infections, or allergic reactions.
Option C: While monocytes are present in the CSF as part of the mononuclear cell response (along with lymphocytes), they are not the most numerous or predominant cell type. Lymphocytes are significantly more abundant.
Option D: A predominance of neutrophils is the classic sign of acute bacterial (pyogenic) meningitis, not chronic infections like tuberculosis.

Clinical Relevance

Nursing practice connection: Use the key finding related to Cerebrospinal fluid (CSF) analysis in tubercular meningitis to guide bedside assessment, documentation, and the next nursing action.
Analyzing the predominant cell type in CSF is a critical first step in differentiating the cause of meningitis, which directly impacts the choice between antibacterial, antiviral, or anti-tubercular therapy.
The classic CSF triad for TB meningitis is: 1) Lymphocytic pleocytosis, 2) Markedly low glucose (hypoglycorrhachia), and 3) Very high protein.
What if? If the CSF report showed a predominance of neutrophils (greater than 80%), the immediate clinical suspicion would shift to acute bacterial meningitis, warranting urgent administration of broad-spectrum antibiotics, not anti-tubercular drugs.

How to Approach the Question

Identify the core of the question: It asks for the 'predominant cell type' in the CSF for a specific disease, 'tubercular meningitis'.
Categorize the disease process. Tuberculosis is a chronic bacterial infection.
Recall the general patterns of cellular response in CSF: Acute bacterial infections cause a neutrophil response. Chronic infections (like TB) and viral infections cause a lymphocyte response.
Evaluate the options based on this principle: Neutrophils are for acute bacterial meningitis. Eosinophils are for parasitic/fungal infections. Lymphocytes are for chronic/viral meningitis.
Select Lymphocytes as the correct answer because it matches the chronic inflammatory nature of tubercular meningitis.

Concept Tested & Keywords

Concept Tested: Cerebrospinal fluid (CSF) analysis in tubercular meningitis
Stem keywords: cerebrospinal fluid, tubercular meningitis, predominant cell type
Lead-in keywords: Which
Clinical cues: Diagnosis: tubercular meningitis

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E6 Medicine Harrison 22e Part 1 pp. 1174-1176, 1165-1167

Practise the full BTSC Staff Nurse 31 July-2025

Attempt every question from this paper in a timed mock, then review the full solution for each one.