Welcome to PracticeUpdate! We hope you are enjoying access to a selection of our top-read and most recent articles. Please register today for a free account and gain full access to all of our expert-selected content.
Already Have An Account? Log in Now
Clinical Significance of a Single CSF Immunoglobulin Band
TAKE-HOME MESSAGE
-
The authors of this retrospective study evaluated the clinical significance of a single cerebrospinal fluid immunoglobulin band for the diagnosis of inflammatory neurologic disorders. They identified 214 patients with a single immunoglobulin band. Among these patients, 17 were eventually diagnosed with multiple sclerosis, and 71 were diagnosed with another inflammatory neurologic disorder; this accounted for 41% of the patients with a single immunoglobulin band. Eventually, 37 patients (17%) were diagnosed with cancer.
- These data are important for neurologists in interpreting a single CSF immunoglobulin band. Workup should be repeated as clinically indicated given that over 50% of these patients were eventually diagnosed with an inflammatory disorder.
abstract
This abstract is available on the publisher's site.
Access this abstract nowBACKGROUND
To demonstrate an inflammatory process in the central nervous system, the presence of at least two immunoglobulin (Ig) bands in the cerebrospinal fluid (CSF) is required. So far, the presence of a single abnormal Ig band is considered as negative.
OBJECTIVE
The objective was to assess retrospectively the significance of a single CSF Ig band in clinical practice.
METHODS AND RESULTS
Out of 10,286 CSF analyses, we retained 214 results with single Ig. An inflammatory neurological disorder was diagnosed in 41% of patients.
CONCLUSION
Despite a modest sensitivity, the presence of a single CSF Ig band may be a biomarker of an inflammatory mechanism and, as such, may prompt the clinician to repeat the analysis when the clinical context remains suggestive.
Additional Info
Disclosure statements are available on the authors' profiles:
Clinical Significance of a Single Cerebrospinal Fluid Immunoglobulin Band: A Retrospective Study
Mult. Scler. 2020 Dec 09;[EPub Ahead of Print], M Tusseau, E Cheli, R Marignier, F Poitevin, C Malcus, M Gossez, J Bancel, G Monneret, S VukusicFrom MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
Neurology
In this study, the authors retrospectively assessed clinical data of 214 patients with a single cerebrospinal fluid (CSF) IgG band at isoelectric focusing (IEF). Of these, 41% were diagnosed with an inflammatory central nervous system (CNS) disorder; and, of 14 patients who underwent a follow-up spinal tap, 5 (36%) had at least two CSF-restricted IgG bands.
These findings are in line with those from other studies showing that roughly one-half of patients with this IEF finding have an inflammatory neurological disorder, including multiple sclerosis (MS), and that, at follow-up spinal taps, approximately one-third of patients have developed an oligoclonal response.
Patients with a single CSF IgG band may go unnoticed as some laboratories only report the presence (ie, at least two CSF-restricted IgG bands) or absence of oligoclonal bands (OCB). OCB are markers of an intrathecal activation of the humoral immune system and, as such, are useful in the diagnostic workup of MS and other inflammatory/infectious CNS disorders. The presence of a single CSF IgG band may reflect a very early stage of the pathological inflammatory process, in which an oligoclonal response has yet to develop.
Caution is warranted, however, as the IEF technical shortcomings, as well as the difficulties in interpreting IEF runs, are well-known and also because, on the other hand, approximately one-half of patients with a single CSF IgG band do not have a neurological inflammatory disorder.
In this context, the presence of an elevated kappa index (CSF/serum kappa free light chain divided by the CSF/serum albumin ratio) as a marker of intrathecal Ig synthesis, may be useful in order to correctly classify patients.1
The practical message reinforced by this study is to report the presence of a single CSF IgG band as it alerts the clinician of the possible presence of an inflammatory CNS disorder.
Reference