CSF profiles

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|| || Color || Opening Pressure || WBC || Diff || RBC || Protein || Glucose || Misc ||
| Normal | Clear, colorless | 70-200 mm H2O | 0-5 | Mononuclear | 0 | <45-50 mg/dL | >2/3 serum | |
| Bacterial meningitis | Cloudy, straw-colored | increased | >100 | PMN | 0 | 100s-1000s | decreased \\ (CSF/serum < 0.2) | Gram stain, culture |
| Viral meningitis | Cloudy, colorless | normal | 10s-100s | Lymphs | 0 | mildly elevated | normal | May see PMNs early |
| Fungal / TB | Cloudy, straw-colored | increased | 10s-100s | Lymphs, Monos \\ (PMNs early) | 0 | 100s | decreased \\ (CSF/serum < 0.3) | AFB fungal cultures |
| HSV / viral encephalitis | Cloudy, straw-colored | normal to increased | ¿ \\ (normal in ~3%) | Lymphs | ¿ in HSV \\ otherwise 0 | normal to ¿ | normal | Check HSV PCR |
| Cancer / Lymphomatous Meningitis | Cloudy, straw-colored | increased | normal to 100s | PMNs and lymphs | ¿¿ | normal to increased | normal to decreased | Cytology positive in ~50% |
| Subarachnoid hemorrhage | Cloudy, pink | increased | RBC/WBC ratio similar to serum | PMNs and lymphs | RBC/WBC ratio similar to serum  | 10s-100s | normal | RBCs last 2 weeks, xanthochromia lasts longer |
| AIDP | Clear, yellow | normal | normal to 10s | Mononuclear | 0 | normal to 100s | normal | Protein normal early on |
| MS | Clear, colorless | normal | normal to 10s | normal or mononuclear predominance | 0 | ¿ | normal | Oligoclonal bands, IgG index |
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Note: these CSF profiles are rules of thumb, and exceptions are frequent. Most importantly, the diff is predominantly lymphocytic in some cases of bacterial meningitis. As another example, PMNs sometimes predominate in viral, fungal, TB, or carcinomatous meningitis.


CSF studies: Volumes & miscellaneous lab info

(compiled from the UMHS pathology handbook)

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|| Study || COE code || Normal volume (mL) || Minimum volume (mL) || Notes ||
| 14-3-3 protein | SENDOUT | 1 | 0.5 | |
| Acanthamoeba / Naegleria exam | ML MISC | 1 | 0.5 | |
| aerobic culture/smear | CSFG | 1 | 0.5 | Specimen collection:  Cleanse area with soap solution, remove soap with 70% ethanol.  Apply 1% tinture of iodine.  Iodine must remain on skin 2-4 minutes for maximum effectivemenss.  Remove with 70% alcohol.  If patient is allergic to iodine, alcohol alone can be used.  DO NOT touch prepared skin during collection of specimen. |
| AFB culture | AFB | 0.5 - 10 | | Staff physician or member of ID service must contact the lab with the clinical necessity for the test before it will be processed.  Clinical indication must be written on requisition. |
| amino acids, quantitative | CAA | 2 | 1 | |
| anaerobe culture | ANNC | 0.5 - 5 | | Same as AFB culture.  Also, specimens with volume < 1 mL must be sent in anaerobic transport. |
| arbovirus antibody panel | ML MISC | 0.75 \\ (+0.75 of serum) | 0.5 \\ (+0.5 of serum) | Includes California encephalitis, Eastern equine encephalitis, St. Louis encephalitis, West Nile Virus, Western equine encephalitis. |
| beta-2 transferrin | OLI BAND | 50 (microL) | 10 (microL) | |
| beta glucuronidase | BGCC | 1 | 0.5 | |
| BKV DNA PCR | | 0.3 - 1 | | |
| Blastomyces antibody | CBLASTO | 4 | 3 | |
| cell count & differential | CSF FC, CSF FD | 1 | 1 | Get to lab within 1 hour. |
| Coccidioides antibody | CCOCCI | 4 | 3 | |
| Cryptococcus antigen | CRAGC | 1 | 0.5 | |
| cytology | CCSF | | 1 | Cannot be split for other tests.  Left over from other CSF samples cannot be used.  Results will not be released without a clinical history provided. |
| Enterovirus DNA PCR | PCREV | 1 | 0.5 | |
| fungal culture | FNG | 0.5 - 10 | | Send immediately to lab.  If suspecting cryptococcal meningitis, a specimen should also be submitted for cryptococcus antigen screen.  Do not refridgerate as this can inhibit Histoplasma growth.  Clinical diagnosis must be written on requisition. |
| fungal antibody panel | FUNCSF | 4 | 3 | |
| glucose | GLCSF | 1 | 0.5 | |
| glutamic acid decarboxylase antibody | | 1 | 1 | |
| HHV-6 DNA PCR | | 0.3 - 1 | | |
| HHV-8 DNA PCR | | 0.3 - 1 | | |
| Histoplasma antibody | CHISTO | 4 | 3 | |
| HSV DNA PCR | PCR HSV | 1 | 0.5 | |
| Immunoglobulin G Index | GIN | 0.5 | 0.5 | Send with 0.5 mL serum.  Serum should be sent in SST tube.  Can be rejected if more than one request in 28 days. |
| Immunoglobulin G and albumin | G ALB | 0.5 | 0.25 | May be rejected if gross hemolysis seen or if more than one specimen received in 28 days. |
| JCV DNA PCR | | 1.5 | 1 | |
| lactic acid dehydrogenase | LDCSF | 1 | 0.5 | |
| lactic acid | LACCSF | 1 | 0.5 | |
| Lyme disease antibody | ML MISC | 0.5 | 0.25 | Requires serum specimen collected at the same time. |
| myelin basic protein | MBPC | 0.5 | 0.25 | |
| oligoclonal bands | OLI BAND | 3 \\ (+ 1 of serum) | 2.5 \\ (+ 0.5 of serum) | CSF and serum may be collected within 3 weeks of each other. |
| paraneoplastic antibody evaluation | PAEVAL | 4 | 3 | |
| Parvovirus B19 DNA PCR | | 1.5 | 1 | |
| protein | PRCSF | 1 | 0.5 | |
| Rubeola virus antibody (IgG & IgM) | ML MISC | 0.25 | 0.1 | |
| VDRL | ML MISC | 0.5 | 0.2 | Should only be performed if serum FTA is reactive, otherwise, may be rejected by lab. |
| Toxoplasma antibody (IgG & IgM) | ML MISC | 1 | 0.5 | |
| viral culture (incl/excl CMV) | | | 2 | Includes HSV culture. |
| West Nile virus antibody (IgG & IgM) | ML MISC | 0.5 | 0.25 | |
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