Home Borrelia cerebrospinal fluid diagnosis

A dangerous bacteria called Borrelia causes serious infections in man. In late stages of this disease, the human brain is attacked by these bacteria.
Therefore, diagnosis of Borrelia infections in the brain is very important, but involves several complicated calculations of the measurement results of Borrelia diagnostics.
Below, you can see these calculations.


Application version: May 2000

Cerebrospinal Fluid Diagnosis

To be used with
Borrelia IgG recombinant antigen ELISA
(cat.no. BI-21032)
and
Borrelia IgM recombinant antigen ELISA
(cat.no. BI-21042)

Contents

  1. Introduction
  2. Literature
  3. Sample dilution
  4. Calculation & interpretation of the results using MS EXCEL
  5. Test evaluation
  6. Assessment of the results
  7. Calculation of the Borrelia-specific antibody-concentrations in serum and cerebrospinal fluid
  8. Calculation of QIgG, QIgM, QAlb, Qlim(IgG), Qlim(IgM)
  9. Calculation of the specific antibody-indexes AIIgG and AIIgM
  10. Interpretation of the antibody-indexes
  11. Clinical evaluation data
    11.1. Borrelia IgG
    11.2. Borrelia IgM

 

1. Introduction

The diagnosis of neuroborreliosis relies on the detection of inthratecally produced Borrelia-specific IgG and IgM antibodies. IgG and IgM concentrations are estimated in BBU/ml (Biomedica Borrelia Units/ml) by quantitative measurements using IgG and IgM ELISAs.
The ratios between specific Borrelia antibody-concentrations and total immunoglobulin-concentrations are estimated for both serum and cerebrospinal fluid (CSF). These so-called antibody-indexes are used to distinguish between inthratecally produced Borrelia-antibodies, and those who entered the cerebrospinal fluid space passively by passing the blood-brain barrier.

The limit Qlim is calculated using the quotient diagram according to Reiber(1,2), which guarantees that no false-negative antibody-indexes are calculated for a polyspecific inthratecally immune response.

Borrelia-antibodies are estimated quantitatively in serum and cerebrospinal fluid. Only in case of positive cerebrospinal fluid results 5 BBU/ml), total-IgG and/or total-IgM and albumin in serum and cerebrospinal fluid have to be determined in order to calculate the Borrelia-specific antibody-indexes. The following protocol describes the necessary calculations.

 

2. Literature

  1. Reiber H (1995) Die diagnostische Bedeutung neuroimmunologischer Reaktionsmuster im Liquor cerebrospinalis. Lab. med. 19: 444-462
  2. Tumani H, Nlker G und Reiber H (1995) Relevance of cerebrospinal fluid parameters for early diagnosis in neuroborreliosis. Neurology 45: 1663-1670

 

3. Sample dilution

The assay is performed according to the Biomedica Borrelia IgG and IgM ELISA package inserts.

 

Sample dilution

IgG - serum
IgG - cerebrospinal fluid
1 : 101
1 : 3
IgM - serum
IgM - cerebrospinal fluid
1 : 101
1 : 2

Samples with results >30 BBU/ml should be repeated by using higher dilution rates. We suggest dilution rates as described in chapter 7.

 

4. Calculation & interpretation of the results using MS EXCEL

In the following chapters 5-10, it is shown how to evaluate, assess, and interpret the measurement results obtained in chapter 3 according to the Reiber quotient diagram(1,2).
However, these calculations aren't very handy. To simplify the calculation and documentation of the measurement results, an easy-to-use utility was developed, which is basically a MS EXCEL 97 file with a macro in it.

Please click here to download a ZIP-file containing the Excel macro together with instructions for use in PDF-format (size: 287 kB).

 

5. Test evaluation

To evaluate the results, the BBU/ml for sera and cerebrospinal fluides for both IgG and IgM are calculated, as described in the package inserts for IgG and IgM.

The same formula applies to both IgG und IgM:

BBU/ml formula

 

 

Result

Evaluation

Serum > 11 BBU/ml
9 - 11 BBU/ml
< 9 BBU/ml

positive
borderline
negative

Cerebrospinal fluid 5 BBU/ml
< 5 BBU/ml

positive
negative

 

6. Assessment of the results

The results from chapter 5 are assessed as follows:

Result

Assessment and further procedure

Serum 11 BBU/ml
CSF < 5 BBU/ml
This is a negative result for Borrelia IgG-antibodies in serum and cerebrospinal fluid, which means:
no indication for a neuroborreliosis, therefore
estimation of the antibody-index AIIgG not necessary.
Serum > 11 BBU/ml
CSF < 5 BBU/ml
This is a positive result for Borrelia IgG-antibodies in serum, and a negative result for Borrelia IgG-antibodies in cerebrospinal fluid, which means:
evidence for an acute or past Borrelia-infection, therefore
no indication for a neuroborreliosis, estimation of the antibody-index AIIgG not necessary.
Serum 11 BBU/ml
CSF 5 BBU/ml
This is a negative result for Borrelia IgG-antibodies in serum, and a positive result for Borrelia IgG-antibodies in cerebrospinal fluid, which means:
possibility for neuroborreliosis, therefore
estimation of the antibody-index AIIgG is necessary.
Serum > 11 BBU/ml
CSF 5 BBU/ml
This is a positive result for Borrelia IgG-antibodies in serum, and a positive result for Borrelia IgG-antibodies in cerebrospinal fluid, which means:
possibility for neuroborreliosis, therefore
estimation of the antibody-index AIIgG is necessary.

If the result in cerebrospinal fluid is negative, estimation of the Borrelia-specific antibody-index isn't necessary and the protocol should be stopped here.
If either IgG- or IgM-results in cerebrospinal fluid are positive, the protocol should be proceed.
Subsequently, the procedures for IgG- and IgM-calculations are identical.

The Borrelia-specific antibody-index is only calculated upon a positive result for cerebrospinal fluid.

 

7. Calculation of the Borrelia-specific antibody-concentrations in serum and cerebrospinal fluid

The Biomedica Borrelia ELISA results are linear up to 30 BBU/ml.
Serum- and/or cerebrospinal fluid-results above 30 BBU/ml should be re-assayed using higher dilution rates.

Suggestion:

 

original dilutions

further dilutions
Serum IgG and IgM 1:101 1:1010 1:5050
Cerebrospinal fluid IgG
Cerebrospinal fluid IgM
1:3
1:2
1:5 1:10
1:5 1:10

The concentration BBU/ml in the undiluted samples is calculated as follows:

Concentration BBU/ml in the undiluted sample = BBU/ml x dilution


Example serum IgG:

measured BBU/ml: 4.4
dilution rate: 1:1010
4.4 x 1010 = 4444 BBU/ml in the undiluted serum
 
Example cerebrospinal fluid IgG: measured BBU/ml: 8
dilution rate: 1:3
8 x 3 = 24 BBU/ml in the undiluted cerebrospinal fluid

The Borrelia-specific IgG- and IgM-quotients Qspez(IgG) resp. Qspez(IgM) are calculated according to the following formulas:

QspezIgG formula  QspezIgM formula

Example IgG: QspezIgG example

 

8. Calculation of QIgG, QIgM, QAlb, Qlim(IgG), Qlim(IgM)

Total-IgG, total-IgM and albumin-concentrations have to be determined in serum and cerebrospinal fluid.
These protein concentrations are then used to calculate the quotients for IgG, IgM and albumin as follows:

QIgG formula QIgM formula QAlb formula


Example IgG:

conc. cerebrospinal fluid = 8.6 mg/l
conc. serum = 9500 mg/l

 
Example albumin: conc. cerebrospinal fluid = 62.7 mg/l
conc. serum = 49000 mg/l

The limits Qlim(IgG) and Qlim(IgM) are calculated using QAlb, according to the following formulas:

Qlim(IgG)QlimIgG formula
Qlim(IgM)QlimIgM formula


Example IgG:

QAlb = 0.00128
Qlim(IgG) =
=
= 0.00087

 

9. Calculation of the specific antibody-indexes AIIgG and AIIgM

The estimated values for QIgG and Qlim(IgG) as well as QIgM and Qlim(IgM) are compared to each other. AIIgG and AIIgM are calculated as follows:

if QIgG < Qlim(IgG)AIIgG formula if QIgM < Qlim(IgM)AIIgM formula
if QIgG > Qlim(IgG)AIIgG formula if QIgM > Qlim(IgM)AIIgM formula

 

10. Interpretation of the antibody-indexes

AIIgG resp. AIIgM 1.3 = normal

AIIgG resp. AIIgM > 1.3 and < 1.5 = borderline

AIIgG resp. AIIgM 1.5 = pathologic


Normal:

AI-values 1.3
Anti-Borrelia-antibodies detected in cerebrospinal fluid moved passively from the serum through the blood-brain barrier into the cerebrospinal fluid space.
No indication for neuroborreliosis.
 
Borderline: AI-values > 1.3 and < 1.5
No clear evidence for an intrathecally production of anti-Borrelia antibodies.
Repetition of the assay recommended, or new collection of serum and cerebrospinal fluid, and repetition of the assay.
 
Pathologic: AI-values 1.5
Strong evidence for an intrathecal production of anti-Borrelia antibodies.
Possibility for neuroborreliosis.

 

11. Clinical evaluation data

11.1. Borrelia IgG

Code No

Clinical Diagnosis

Anamnesis

Therapy

BBU CSF IgG BBU serum IgG

Q Alb

Q spez IgG
1:50

Q IgG

Q lim IgG

AI IgG
1:50 &
1:5050

CSF diagnosis

1:3

1:50

1:101

1:5050

A1
A2
A3
A4
A5
A6
A7
A8
A9

Radikulopathy C6
Involution depression
Psychogenic dizziness
Polyneuropathy
ZB diabet. neuropathy
Lumbago
Osteoporosis
Neurotic depression
Senile dementia, Alzheimer type

Status post neuroborreliosis
Status post borreliosis, first titer, 1998 (IgG)
Status post neuroborreliosis, 1998
Borreliosis, ZB acrodermatitis chronica
2 x eryth. chr. migrans
Status post neuroborreliosis, 1993
Persistent borreliosis, 1999
Status post borreliosis, 1997
Neuroborreliosis

unknown
Rocephin, afterwards 3 weeks p.os, 1996
Rocephin
Vibramycin 200 mg daily, 3 weeks
Antibiosis some months ago
Antibiosis 1993
Rocephin 2g, 2 weeks
Antibiosis 1997, Rocephin 1999
Rocephin 2g, 3 weeks

 

6.0
2.8
1.3
14.1
4.2
3.1
0.9
2.8
3.7

 

7.9
11.5
6.7
37.2
15.7
7.1
3.2
8.4
2.2

0.00646
0.00734
0.00618
0.00948
0.00688
0.00798
0.00599
0.00736
0.00523

0.00752
0.00241
0.00192
0.00375
0.00265
0.00432
0.00278
0.00330
0.01665

0.00304
0.00306
0.00302
0.00415
0.00277
0.00366
0.00287
0.00315
0.00565

0.00473
0.00550
0.00448
0.00741
0.00509
0.00606
0.00431
0.00552
0.00367

2.47025
0.78877
0.63595
0.90461
0.95564
1.18161
0.97065
1.04686

4.53405

borr. positive
borr. negative
borr. negative
borr. negative
borr. negative
borr. negative
borr. negative
borr. negative

borr. positive

B1
B2
B3
B4
B5
B6
B7
B8
B9

healthy control
healthy control
healthy control
healthy control
healthy control
healthy control
healthy control
healthy control
healthy control

  1.1
0.2
0.3
0.1
0.1
0.1
1.8
0.4
0.1
  21.2
1.0
3.2
1.5
1.4
0.8
13.3
2.7
1.9
  0.00791
0.00391
0.01020
0.00330
0.00664
0.00400
0.00861
0.00735
0.00378

--
--
--
--
--
--
--
--
--

--
--
--
--
--
--
--
--
--

--
--
--
--
--
--
--
--
--

--
--
--
--
--
--
--
--
--

borr. negative
borr. negative
borr. negative
borr. negative
borr. negative
borr. negative
borr. negative
borr. negative
borr. negative

 

11.2. Borrelia IgM

Code No

Clinical Diagnosis

Anamnesis

Therapy

BBU CSF IgM

BBU Serum IgM

Q Alb

Q spez IgM

Q IgM

Q lim IgM

AI IgM

CSF diagnosis

1:2

1:101

A1
A2
A3
A4
A5
A6
A7
A8
A9
A10
A11
A12

Radikulopathy C6
Hepatomegaly
Lumbago
Involution depression
Psychogenic dizziness
Polyneuropathy
ZB diabet. neuropathy
Struma multinodosa
Lumbago
Osteoporosis
Neurotic depression
Senile dementia, Alzheimer type

Status post neuroborreliosis
Status post eryth. chr. migrans, 1990
Status post borreliosis
Status post borreliosis, first titer, 1998 (IgG)
Status post neuroborreliosis, 1998
Borreliosis, ZB acrodermatitis chronica
2 x eryth. chr. migrans
Status post neuroborreliosis, 1 month later
Status post neuroborreliosis, 1993
Persistent borreliosis, 1999
Status post borreliosis, 1997
Neuroborreliosis

unknown
Rocephin, 7 days Dec 1998
unknown
Rocephin, afterwards 3 weeks p.os, 1996
Rocephin
Vibramycin 200 mg daily, 3 weeks
Antibiosis some months ago
nothing
Antibiosis 1993
Rocephin 2g, 2 weeks
Antibiosis 1997, Rocephin 1999
Rocephin 2g, 3 weeks

0.2
0.1
0.1
0.2
0.3
0.2
5.8
12.7
0.2
0.3
0.3
0.4

10.3
52.9
2.4
5.1
21.6
7.4
9.5
21.6
4.8
29.0
4.8
8.9

0.00646
0.00327
0.00349
0.00734
0.00618
0.00948
0.00688
0.01262
0.00798
0.00599
0.00736
0.00523

--
--
--
--
--
--
0.01209
0.01164
--
--
--
--

--
--
--
--
--
--
0.00109
0.01481
--
--
--
--

--
--
--
--
--
--
0.00157
0.00410
--
--
--
--

--
--
--
--
--
--
11.12246
2.84127

--
--
--
--

borr. negative
borr. negative
borr. negative
borr. negative
borr. negative
borr. negative

borr. positive
borr. positive

borr. negative
borr. negative
borr. negative
borr. negative

B1
B2
B3
B4
B5
B6
B7
B8
B9

healthy control
healthy control
healthy control
healthy control
healthy control
healthy control
healthy control
healthy control
healthy control

 

0.1
0.5
0.2
0.2
0.3
0.4
0.3
0.2
0.4

12.2
16.9
1.9
8.3
3.1
1.8
2.1
1.1
0.7

0.00791
0.00391
0.01020
0.00330
0.00664
0.00400
0.00861
0.00735
0.00378

--
--
--
--
--
--
--
--
--

--
--
--
--
--
--
--
--
--

--
--
--
--
--
--
--
--
--

--
--
--
--
--
--
--
--
--

borr. negative
borr. negative
borr. negative
borr. negative
borr. negative
borr. negative
borr. negative
borr. negative
borr. negative

 


Last modified: 11. Jun 05