Child pages
  • CSF Analysis
Skip to end of metadata
Go to start of metadata


CSF profiles

Unknown macro: {table-plus}

 

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


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.

  • WBC corrections
    • Reduce wbc by one cell for every 700 RBC¿OR
    • WBC (corr) = WBC (CSF) ¿ WBC (blood) x RBC(CSF)/RBC (blood)
  • Normal csf glucose is ~ 2/3 of serum glucose
  • Corrected protein: subtract 1mg/ml for every 1000 RBC
  • Opening Pressure is only accurate in the lateral decubitus position with legs extended and patient relaxed.
  • Correct coagulopathy with FFP prior to doing LP (INR needs to be <1.5)
  • CSF studies to send (always send the first 4; other depending on clinical setting)
    • Cell count with differential ¿ usually sent on tubes 1 and 4
    • Glucose
    • Protein
    • Gram stain, culture
    • HSV PCR
    • Cryptococcal Ag
    • TB PCR
    • Cytology
    • Oligoclonal bands, IgG index (demyelination) ¿ don¿t forget to send serum for IgG and O-bands at the same time! Myelin basic protein (very nonspecific).
    • Protein 14-3-3 (CJD)
  • Other tests if indicated (ie more specific viral or fungal tests) ¿ collect more CSF than needed so that if other tests become necessary, can add on. Ask the lab to save a tube.
  • Always hand-carry CSF down to the lab and ask for evaluation of xanthochromia w/centrifugation of cloudy/colored specimens.


CSF studies: Volumes & miscellaneous lab info

(compiled from the UMHS pathology handbook)

Unknown macro: {table-plus}

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

 



  • No labels