CSF/Serum Alb. Index
Cerebrospinal fluid (CSF)
Part of Cerebrospinal Fluid (CSF) Analysis

CSF/Serum Albumin Index The CSF/Serum Albumin Index is a key diagnostic tool used to assess the integrity of the blood-brain barrier (BBB). It compares albumin concentrations in the cerebrospinal fluid (CSF) and serum. Since albumin is produced exclusively in the liver and not within the central nervous system (CNS), its presence in the CSF indicates passive diffusion across the BBB. An elevated index suggests increased permeability or disruption of the barrier, making it a reliable marker for BBB dysfunction. Clinical Applications This index is used to evaluate a wide range of neurological conditions, including: Inflammatory CNS diseases (e.g., multiple sclerosis, neurosyphilis) CNS infections (e.g., bacterial or viral meningitis, encephalitis) Traumatic brain injury or hemorrhage Neurodegenerative disorders (e.g., Alzheimer’s disease, vascular dementia) Autoimmune conditions (e.g., CNS involvement in lupus or sarcoidosis) Reference Ranges and Interpretation Age-adjusted thresholds: <6.8 for individuals under 45 years <10.2 for individuals over 45 years General impairment categories: <9: Intact BBB 9–14: Slight impairment 14–30: Moderate impairment 30–100: Severe impairment >100: Complete BBB breakdown Elevated values may indicate: Acute CNS infections (e.g., bacterial meningitis) Autoimmune or inflammatory CNS conditions (e.g., multiple sclerosis, autoimmune encephalitis) Tumors or mechanical trauma (e.g., spinal cord injury, hemorrhage) Key Considerations Paired sample testing: Both serum and CSF must be collected at the same time for accurate calculation. Interpretation in context: Best used alongside the IgG Index (for intrathecal antibody production) and oligoclonal banding. Limitations: Reflects both blood-CSF barrier function (choroid plexus) and cerebrovascular endothelial integrity—cannot distinguish between them. Takeaway The CSF/Serum Albumin Index is an essential biomarker for detecting blood-brain barrier dysfunction, helping diagnose and monitor CNS infections, autoimmune diseases, trauma, and neurodegeneration. Accurate interpretation requires age-based reference ranges and correlation with other laboratory and clinical findings.

Optimal range 0 – 8 index Learn more
Cyclospora cayetanensis
Part of 2200 GI Effects Comprehensive Profile - Stool, Genova Diagnostics

Cyclospora cayetanensis is a coccidian (= intestinal) parasite that causes a diarrheal disease known as cyclosporiasis in humans and possibly in other primates. It belongs to the phylum Apicomplexa and the genus Cyclospora. The species name, "cayetanensis," refers to the Cayetano Heredia University in Lima, Peru, where early epidemiological and taxonomic work on this parasite was conducted. Symptoms of cyclosporiasis include watery diarrhea, loss of appetite, weight loss, abdominal cramps, nausea, and sometimes low-grade fever. The severity of the illness can vary based on factors such as age, the condition of the host, and the size of the infectious dose. Infection with Cyclospora cayetanensis occurs when individuals consume food or water contaminated with the parasite. People living or traveling in countries where cyclosporiasis is endemic may be at an increased risk of infection. The oocysts are shed in the stool of infected individuals and need favorable laboratory conditions to sporulate and become infective. Cyclosporiasis can also be acquired from contaminated produce, leading to outbreaks in developed countries. How is Cyclospora infection treated? The recommended treatment is a combination of two antibiotics, trimethoprim-sulfamethoxazole, also known as Bactrim, Septra, or Cotrim. People who have diarrhea should also rest and drink plenty of fluids.

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