Cerebrospinal fluid ferritin—Unspecific and unsuitable for disease monitoring

Cerebrospinal fluid biomarkers of superficial siderosis in patients with spontaneous intracranial hypotension

BACKGROUND AND PURPOSE

Spontaneous intracranial hypotension (SIH) is an important etiology of infratentorial superficial siderosis (iSS) of the central nervous system. However, the prevalence of iSS amongst patients with SIH is unknown and the imaging findings of iSS might represent a late stage of disease. The aim was to identify cerebrospinal fluid (CSF) biomarkers of iSS in patients with SIH.

METHODS

Consecutive patients evaluated for SIH at our institution between May 2017 and January 2019 were included. Lumbar CSF samples were analyzed for the presence of ferritin and bilirubin. Magnetic resonance imaging was assessed for the presence of iSS.

RESULTS

Twenty-four patients with SIH were included. CSF samples were positive for bilirubin in 2/19 (10.5%). CSF ferritin was elevated in 7/23 (30.4%). Signs of iSS on imaging were present in four patients (16.7%). All patients with imaging signs of iSS demonstrated elevated CSF ferritin. Ferritin level was significantly higher amongst patients demonstrating iSS compared to those without (median 45.0 vs. 11.0 μg/l; p = 0.003). Symptom duration was longer in patients with iSS than in patients without iSS (median 40 months vs. 9 months, p = 0.018).

CONCLUSION

Cerebrospinal fluid alterations indicative of iSS are prevalent amongst patients with SIH. It is speculated that a preclinical phase without symptoms or imaging signs but during which elevated biomarkers of the disease are apparent from CSF analysis might exist. It is suggested that measurement of CSF ferritin is incorporated in the work-up of patients with SIH to identify those at risk of developing iSS.

Interrelations of Alzheimer´s disease candidate biomarkers neurogranin, fatty acid-binding protein 3 and ferritin to neurodegeneration and neuroinflammation

There is growing evidence that promising biomarkers of inflammation in Alzheimer´s disease (AD) and other neurodegenerative diseases correlate strongest to levels of tau or neurofilament, indicating an inflammatory response to neuronal damage or death. To test this hypothesis, we investigated three AD candidate markers (ferritin, fatty acid binding protein 3 (FABP-3), and neurogranin) in interrelation to established AD and inflammatory protein markers. We further aimed to determine if such interrelations would be evident in pathological subjects only or also under non-pathological circumstances. Cerebrospinal fluid levels of the three proteins were quantified in samples from the University Clinic of Bonn (UKB) Department of Neurodegenerative Diseases & Geriatric Psychiatry, Germany. Data were analyzed based on clinical or biomarker-defined stratification of subjects with adjustment for covariates age, sex, and APOE status. Levels of ferritin, FABP-3 and neurogranin were elevated in subjects with pathological levels of t-tau independent of beta-amyloid status. The three markers correlated with each other, tau isoforms, age, and those inflammatory markers previously described as related to neurodegeneration, predominantly sTREM2, macrophage migration inhibitory factor, soluble vascular endothelial growth factor receptor, soluble vascular cell adhesion molecule 1 (sVCAM-1), and C1q. These interrelations existed in subjects with pathological and sub-pathological tau levels, in particular for FABP-3 and neurogranin. Relations to ferritin were independent of absolute levels of tau, too, but showed differing trajectories between pathological and non-pathological subjects. A specific set of inflammatory markers is highly related to markers of neuronal damage such as tau, neurogranin, or FABP-3. These proteins could be used as readouts of the inflammatory response during the neurodegeneration phase of AD.

S1 guidelines "lumbar puncture and cerebrospinal fluid analysis" (abridged and translated version)

Introduction

Cerebrospinal fluid (CSF) analysis is important for detecting inflammation of the nervous system and the meninges, bleeding in the area of the subarachnoid space that may not be visualized by imaging, and the spread of malignant diseases to the CSF space. In the diagnosis and differential diagnosis of neurodegenerative diseases, the importance of CSF analysis is increasing. Measuring the opening pressure of CSF in idiopathic intracranial hypertension and at spinal tap in normal pressure hydrocephalus constitute diagnostic examination procedures with therapeutic benefits.Recommendations (most important 3-5 recommendations on a glimpse): The indications and contraindications must be checked before lumbar puncture (LP) is performed, and sampling CSF requires the consent of the patient.Puncture with an atraumatic needle is associated with a lower incidence of postpuncture discomfort. The frequency of postpuncture syndrome correlates inversely with age and body mass index, and it is more common in women and patients with a history of headache. The sharp needle is preferably used in older or obese patients, also in punctures expected to be difficult.In order to avoid repeating LP, a sufficient quantity of CSF (at least 10 ml) should be collected. The CSF sample and the serum sample taken at the same time should be sent to a specialized laboratory immediately so that the emergency and basic CSF analysis program can be carried out within 2 h.The indication for LP in anticoagulant therapy should always be decided on an individual basis. The risk of interrupting anticoagulant therapy must be weighed against the increased bleeding risk of LP with anticoagulant therapy.As a quality assurance measure in CSF analysis, it is recommended that all cytological, clinical-chemical, and microbiological findings are combined in an integrated summary report and evaluated by an expert in CSF analysis.

Conclusions

In view of the importance and developments in CSF analysis, the S1 guideline "Lumbar puncture and cerebrospinal fluid analysis" was recently prepared by the German Society for CSF analysis and clinical neurochemistry (DGLN) and published in German in accordance with the guidelines of the AWMF (https://www.awmf.org). /uploads/tx_szleitlinien/030-141l_S1_Lumbalpunktion_und_Liquordiagnostik_2019-08.pdf). The present article is an abridged translation of the above cited guideline. The guideline has been jointly edited by the DGLN and DGN.

Analysis of blood degradation products and ferritin in the cerebrospinal fluid of dogs with acute thoracolumbar intervertebral disk extrusion, a prospective pilot study

Background

Hemorrhage in the spinal canal leads to further damage of the spinal cord influencing outcome in dogs with intervertebral disk (IVD) extrusion. The aim of the study was to evaluate blood degradation products and ferritin in the cerebrospinal fluid (CSF) of dogs with thoracolumbar IVD extrusion, and their association to clinical parameters and MRI findings.

Results

In the CSF of dogs with IVD extrusion, both net oxyhemoglobin absorption (NOA) and net bilirubin absorption (NBA) were significantly higher compared to the control groups of dogs with steroid responsive meningitis arteritis (SRMA) and idiopathic epilepsy (IE) (P < 0.001), but NOA compared to the idiopathic epilepsy group contaminated artificially with blood (IEc) was not (P = 0.890). Ferritin concentration was significantly higher in dogs with IVD extrusion compared to dogs with IE (P = 0.034), but not to dogs with SRMA (P = 0.526). There was no association between NOA, NBA or ferritin concentration and severity or duration of clinical signs. In dogs with a higher ferritin concentration the outcome was better (P = 0.018). In dogs with evidence of hemorrhage on MRI, NOA and NBA were significantly higher (P = 0.016, P = 0.009), but not ferritin (P = 0.0628).

Conclusion and clinical importance

Quantification of blood degradation products and ferritin in the CSF of dogs to assess subarachnoidal hemorrhage is feasible; however, larger case numbers are needed to evaluate the relevance of NBA and ferritin as prognostic indicators.

Elevated serum ferritin level as a predictor of reduced survival in patients with sporadic amyotrophic lateral sclerosis in China: a retrospective study

Objective: The objective of this study was to compare iron metabolic variables in the serum and cerebrospinal fluid (CSF) of patients with sporadic amyotrophic lateral sclerosis (sALS) with those of patients with multiple system atrophy (MSA) and control subjects. We also assessed the correlations of these variables with sALS progression and severity and estimated their roles in predicting prognosis. Methods: We retrospectively collected iron metabolic parameters, including serum levels of iron, ferritin, transferrin levels and total iron binding capacity and the CSF level of ferritin, from 435 sALS patients, 176 MSA patients and 431 control subjects. Results: Serum ferritin levels were significantly higher in the sALS group compared with the MSA and control groups in both males (p = 0.001 and p < 0.0001, respectively) and females (p = 0.034 and p < 0.0001, respectively). However, serum transferrin levels were significantly lower in females of the sALS group compared with the MSA (p = 0.016) and control (p = 0.015) groups. The CSF ferritin level and the serum levels of total iron binding capacity and iron were similar among the sALS, MSA and control groups. Survival analysis demonstrated that higher serum ferritin levels were predictors of reduced survival of sALS patients. No correlations between iron metabolic variables and clinical parameters were found. Conclusion: An elevated serum ferritin level is associated with reduced survival of sALS patients. However, the levels of iron metabolic parameters were not associated with clinical deterioration or disease severity at diagnosis.

Cerebrospinal fluid abnormalities in meningeosis neoplastica: a retrospective 12-year analysis

BACKGROUND

Meningeosis neoplastica is a diffuse metastatic spread of tumor cells in the subarachnoid space. Although first recognized in 1870, systematic investigations regarding cerebrospinal fluid (CSF) constituents in this condition are scarce.

METHODS

Routine CSF samples analyzed from 2001 to 2012 at the Laboratory of Clinical Neurochemistry, University of Göttingen, were re-evaluated. Patients, whose CSF contained malignant cells were included in this study.

RESULTS

Patients (n = 132, age 59.1 ± 29.1, 58% women) were identified, whose CSF contained malignant cells. The most frequent primary tumor was breast cancer (32.6%), followed by lung cancer (25.0%) and hematologic malignancies (21.2%). The most frequent clinical symptoms were affections of cranial nerves (41.7%), psychiatric abmormalities (32.6%) and radicular lesions of the lower extremities (20.5%). CSF cell counts ranged from 0 to 4692 cells/μl (median 4 cells/μl) and were elevated in 50%. The CSF-to-serum albumin ratio was abnormal in 69.4%. It ranged from 1.8 to 330 x 10^-3 (median 17.5 x 10^-3). Total CSF protein ranged from 166 to 15,840 mg/l (median 1012 mg/l). CSF lactate was elevated (>2.4 mmol/l) in 65.2% [3.6 mmol/l (1.3/15.6 mmol/l); median (minimum/maximum)]. In 50% of all patients CSF lactate was ≥3.5 mmol/l. The CSF cell counts correlated significantly with the CSF lactate levels and the CSF protein contents. In 56 of 118 CSF samples (47.5%) ferritin was elevated, and in 25 of 65 carcinoma patients (38.5%) an intrathecal production of carcinoembryonic antigen (CEA) was detected. Granulocytes were found in 52.7% of the CSF samples. The percentages of granulocytes and lymphocytes were higher in samples with an elevated cell count.

CONCLUSION

In approximately 50% of CSF samples with meningeosis neoplastica the CSF cell count is not elevated. Diagnosis may be missed when only CSF samples with elevated cell counts are subjected to cytological analysis. CSF lactate and protein and the CSF-to-serum albumin ratio are frequently increased in meningeosis neoplastica. The differential diagnosis between meningeosis neoplastica and central nervous infections, in particular tuberculous or fungal meningitis, can be difficult.