Autoimmune glial fibrillary acidic protein astrocytopathy mimics infectious meningitis: Two case reports

The discrimination between autoimmune glial fibrillary acidic protein astrocytopathy and tuberculous meningitis

OBJECTIVE

The differential diagnosis between autoimmune glial fibrillary acidic protein astrocytopathy (AGFAPA) mimicking tuberculous meningitis and tuberculous meningitis (TBM) remains challenging in clinical practice. This study aims to identify the clinical, laboratory parameters, and clinical score systems that may be helpful in differentiating AGFAPA from TBM.

METHOD

Overall 22 AGFAPA patients who were initially misdiagnosed as TBM (AGFAPA-TBM) and 30 confirmed TBM patients were included. The clinical, laboratory, imaging parameters, Thwaites systems, and Lancet consensus scoring systems (LCSS) of all patients were reviewed. Logistic regression was employed to establish a diagnostic formula to differentiate AGFAPA-TBM from TBM. The receiver operating characteristic (ROC) curve was applied to determine the best diagnostic critical point of the formula.

RESULTS

Urinary retention was more frequent in AGFAPA-TBM patients (72.7% vs 33.3%, p = 0.012). A significantly lower ratio of T-SPOT. TB was noted in AGFAPA-TBM patients (9.1% vs 82.1%, p < 0.001). We found the LCSS was able to differentiate AGFAPA-TBM from TBM (AUC value 0.918, 95% CI=0.897-0.924). Furthermore, we set up a new scoring system with three variables: urinary retention, T-SPOT. TB, and cerebral imaging criteria in LCSS. The proposed diagnostic score ranges from -8 to 2, and a score of ≥ 0 was suggestive of AGFAPA-TBM (AUC value 0.938, 95% CI=0.878-0.951).

CONCLUSIONS

This study is the first to evaluate the Thwaites system and LCSS in AGFAPA-TBM and TBM. We provide an alternative diagnostic formula to differentiate AGFAPA-TBM from TBM and suggest testing for GFAP antibodies to avoid misdiagnosis when this scoring system meets AGFAPA-TBM.

Glial fibrillary acidic protein astrocytopathy presented as meningitis: A case report

Introduction

Glial fibrillary acidic protein (GFAP) astrocytopathy is a novel autoimmune neurological disorder and is diagnosed by GFAP-IgG in cerebrospinal fluid (CSF) measurement.

Case report

Herein, we described a 10-year-old boy with abnormal neurological symptoms and signs. GFAP-IgG was detected in CSF using cell-based assay (CBA), and his CSF showed an increase in lymphocytes, a slight decrease in glucose and an increase in protein level in the early stage. The cranial MRI showed multiple strips of T2-FLAIR hyperintense signal changes on the surface of medulla oblongata, pons, and gyrus in bilateral cerebral hemispheres. He was treated with immunoglobulin (IVIG) and high-dose methylprednisolone pulse treatment, and his clinical presentations gradually improved.

Conclusion

We highlight that patients with normal inflammatory markers in peripheral blood have obvious meningitis-like symptoms, and clinicians need to consider GFAP astrocytopathy. The early diagnosis and treatment of GFAP astrocytopathy are important for improving the prognosis.

case of autoimmune GFAP astrocytopathy with eosinophils in the cerebrospinal fluid

Cerebrospinal fluid (CSF) eosinophilia is associated with a narrow differential, primarily including parasitic and fungal infections, neoplasm, and chemical meningitis. It has rarely been reported in neuroinflammatory conditions including as a finding of CSF cytology in two autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy cases. Here we describe a case of autoimmune GFAP astrocytopathy with classic clinical and radiographic features as well as presence of eosinophils in the CSF. This case highlights a potential association of eosinophils in the CSF with autoimmune GFAP astrocytopathy, which may suggest its inclusion in the differential diagnosis of eosinophilic meningitis, encephalitis, or myelitis.

Clinical characteristics of patient with GFAP-IgG: a review of 31 patients from two tertiary referral centers in China

OBJECTIVE

This study presents a comprehensive analysis of the clinical characteristics of 31 patients exhibiting cerebrospinal fluid (CSF) and/or serum positivity for GFAP-IgG, with a specific emphasis on 24 cases demonstrating only GFAP-IgG positivity. The investigation thoroughly evaluates their clinical, radiological, and laboratory features, as well as treatment responses, with the objective of offering clinicians potential diagnostic and therapeutic approaches.

METHODS

A total of 31 patients with GFAP-IgG in the CSF and/or serum were registered between August 2016 and August 2021 at the General Hospital of Ningxia Medical University and Huashan Hospital of Fudan University. We retrospectively reviewed their clinical records.

RESULTS

Overall, the patients were positive with GFAP-IgG in their CSF (15/31), in serum (6/31), and both CSF and serum (10/31). Among them, two were eventually diagnosed with astroglioma and primary central nervous system lymphoma, respectively; one patient had typical multiple sclerosis; three exhibited overlapping GFAP-IgG and aquaporin-4-IgG (AQP4-IgG); and one patient was coexisting N-methyl-D-aspartate receptor IgG. The remaining 24 patients were only GFAP-IgG positive. In total, 22 out of the 24 patients had abnormal MRI outcomes, involving the brain, meninges, and spinal cord. Besides, seven of the 24 patients developed optic neuritis. The CSF protein levels positively correlated with the Expanded Disability Status Scale score (EDSSs). Significantly decreased EDSSs, modified Rankin Scale score, GFAP-IgG titer, CSF protein level, and CSF white blood cell counts were observed after immunomodulatory therapy.

CONCLUSION

The clinical manifestations of GFAP-IgG exhibit a wide range of phenotypes that lack specificity. These findings emphasize the significance of not exclusively relying on the presence of antibodies to diagnose GFAP-A, but rather integrating them with the clinical phenotypes. GFAP-IgG testing enables the diagnosis of autoimmune GFAP astrocytopathy, a treatable autoimmune disease affecting the central nervous system. This condition provides opportunities for investigating innovative mechanisms of CNS autoimmunity and inflammation.

Autoimmune glial fibrillary acidic protein astrocytosis mimicking tuberculous meningitis: a retrospective study

BACKGROUND

This study aimed to summarize the clinical features of Autoimmune Glial Fibrillary Acidic Protein Astrocytosis mimicking tuberculosis meningitis to improve clinicians' understanding of this disease.

METHODS

We retrospectively analyzed the clinical manifestations, cerebrospinal fluid results, and imaging data of five patients with Autoimmune Glial Fibrillary Acidic Protein Astrocytosis mimicking tuberculous meningitis who were admitted to Xiangya Hospital Central South University between October 2021 and July 2022.

RESULTS

Five patients were aged 31-59 years, with a male-to-female ratio of 4:1. Among the cases reviewed, four had a history of prodromal infections manifesting as fever and headache. One patient developed limb weakness and numbness with clinical manifestations of meningitis, meningoencephalitis, encephalomyelitis, or meningomyelitis. Cerebrospinal fluid analysis revealed an increased cell count in five cases, with a lymphocyte majority. All five cases had a CSF protein level > 1.0 g/L, CSF/blood glucose ratio < 0.5, and two patients had CSF glucose < 2.2 mmol/L. Decreased CSF chloride was observed in three cases, while increased ADA was observed in one case. Both serum and cerebrospinal fluid were positive for anti-GFAP antibodies in three cases, while in two cases, only CSF was positive for anti-GFAP antibodies. Additionally, hyponatremia and hypochloremia were observed in three cases. No tumors were detected in any of the five patients during tumor screening, and all five cases had a good prognosis following immunotherapy.

CONCLUSION

Anti-GFAP antibody testing should be routinely performed in patients with suspected tuberculosis meningitis to avoid misdiagnosis.

Magnetic Resonance Imaging Characteristics of Autoimmune Glial Fibrillary Acidic Protein (GFAP) Astrocytopathy: A Pediatric Series in Southwest China

Objective

To investigate and summarize the magnetic resonance imaging (MRI) manifestations of autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy in children.

Methods

We retrospectively analyzed data from 17 pediatric patients with autoimmune GFAP astrocytopathy confirmed by the detection of GFAP autoantibodies in cerebrospinal fluid in our single-center. Furthermore, we reviewed current literature and summarized previous findings on the MRI characteristics of this disease in children.

Results

In these 17 patients, the clinical manifestations and results of CSF analysis were suggestive of autoimmune disorder, with a good improvement. The lesions on MRI were most commonly located in the bilateral basal ganglia (70.6%), thalamus (64.7%), cerebral white matter (29.4%). 93.3% of the cerebral lesions were relatively scattered and small, 80% of the spinal lesions presented as longitudinally extensive ones. Both periventricular radial linear (PVRL) (53.8%) and punctate or linear enhancement in basal ganglia and thalamus (53.8%) were commonly observed, followed by the leptomeningeal enhancement (46.2% in the brain and 62.5% in the spinal cord). We then included 55 pediatric patients with MRI data from current literature in our analysis (n = 72, 44 males). Our results revealed similar MRI findings but the enhancement pattern between our series and previously published cases, that is, leptomeningeal enhancement in the brain 46.2% vs 31.4%, in spinal cord 62.5% vs 18.4%, and PVRL enhancement 53.8% vs 11.2%. There were no detailed reports on punctate or linear enhancement.

Conclusion

The MRI characteristics of autoimmune GFAP astrocytopathy in children could be suggestive. Scattered and small lesions (especially punctate or linear) in the bilateral thalamus, basal ganglia, and white matter, as well as longitudinally extensive spinal cord lesions (if present), with punctate, PVRL and leptomeningeal enhancement might be a distinct indication for the early diagnosis of this disorder.

Case report: Autoimmune glial fibrillary acidic protein astrocytopathy misdiagnosed as tuberculous meningitis

Introduction

Autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy is a new form of autoimmunity-mediated central nervous system disease. It is especially easy to misdiagnose when clinical symptoms and cerebrospinal fluid (CSF) indicators are similar to those observed in patients with tuberculous meningitis (TBM).

Methods

We retrospectively analyzed five cases of autoimmune GFAP astrocytopathy that were initially misdiagnosed as TBM.

Results

In the five reported cases, all but one patient had meningoencephalitis in the clinic, and all patients exhibited increased pressure, lymphocytosis, increased protein levels, and decreased glucose levels in their CSF results and did not have typical imaging findings of autoimmune GFAP astrocytopathy. TBM was the initial diagnosis in all five patients. However, we found no direct evidence of tuberculosis infection, and anti-tuberculosis treatment had inconclusive effects. Following a GFAP antibody test, the diagnosis of autoimmune GFAP astrocytopathy was made.

Conclusion

When there is a suspected diagnosis of TBM but TB-related tests are negative, the possibility of autoimmune GFAP astrocytopathy should be considered.

Clinical, imaging features and outcomes of patients with anti-GFAP antibodies: a retrospective study

Objective

To evaluate and compare the clinical features, imaging, overlapping antibodies, and prognosis of pediatric and adult patients with anti-GFAP antibodies.

Methods

This study included 59 patients with anti-GFAP antibodies (28 females and 31 males) who were admitted between December 2019 and September 2022.

Results

Out of 59 patients, 18 were children (under 18 years old), and 31 were adults. The overall cohort's median age at onset was 32 years old, 7 for children, and 42 for adults. There were 23 (41.1%) patients with prodromic infection, 1 (1.7%) patient with a tumor, 29 (53.7%) patients with other non-neurological autoimmune diseases, and 17 (22.8%) patients with hyponatremia. Fourteen (23.7%) patients had multiple neural autoantibodies, with the AQP4 antibody being the most common. Encephalitis (30.5%) was the most common phenotypic syndrome. Common clinical symptoms included fever (59.3%), headache (47.5%), nausea and vomiting (35.6%), limb weakness (35.6%), and disturbance of consciousness (33.9%). Brain MRI lesions were primarily located in the cortex/subcortex (37.3%), brainstem (27.1%), thalamus (23.7%), and basal ganglia (22.0%). Spinal cord MRI lesions often involved the cervical and thoracic spinal cord. There was no statistically significant difference in the MRI lesion site between children and adults. Out of 58 patients, 47 (81.0%) had a monophasic course, and 4 died. The last follow-up showed that 41/58 (80.7%) patients had an improved functional outcome (mRS <3), and children were more likely than adults to have no residual disability symptoms (p = 0.001).

Conclusion

There was no statistically significant difference in clinical symptoms and imaging findings between children and adult patients with anti-GFAP antibodies; Patients with anti-GFAP antibodies may present with normal MRI findings or delayed MRI abnormalities, and patients with overlapping antibodies were common. Most patients had monophasic courses, and those with overlapping antibodies were more likely to relapse. Children were more likely than adults to have no disability. Finally, we hypothesize that the presence of anti-GFAP antibodies is a non-specific witness of inflammation.

Autoimmune glial fibrillar acidic protein astrocytopathy mimicking tuberculous meningitis

Autoimmune glial fibrillar acidic protein (GFAP) astrocytopathy typically presents as acute or subacute meningoencephalitis with or without myelitis. We describe a case of autoimmune GFAP astrocytopathy that mimicked tuberculous meningitis. A man in his 70s was referred to our hospital with lethargy persistent for 2 months, appetite loss for 1 month and fever with headache for 10 days. The cerebrospinal fluid test revealed lymphocytic pleocytosis with elevated adenosine deaminase (ADA). Laboratory investigations ruled out microbial and neoplastic causes. Empirical therapy for tuberculous meningitis combined with corticosteroid improved the patient's condition. Culture for Mycobacterium tuberculosis failed to show microbial growth despite 1 month of incubation. The cerebrospinal fluid was examined for GFAP antibody and returned positive result. Antituberculous agents were discontinued, and corticosteroid was administered until patient's symptoms resolved completely. Thus, clinicians should consider autoimmune GFAP astrocytopathy as one of the differential diagnoses of lymphocytic meningitis with elevated ADA.

Comparison of clinical and radiological characteristics in autoimmune GFAP astrocytopathy, MOGAD and AQP4-IgG+ NMOSD mimicking intracranial infection as the initial manifestation

OBJECTIVE

Several autoimmune CNS inflammatory diseases, including autoimmune glial fibrillary acidic protein astrocytopathy (A-GFAP-A), myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) and aquaporin-4-immunoglobulin-G-positive neuromyelitis optica spectrum disorders (AQP4-IgG⁺NMOSD) often presented initially with similar symptoms mimicking intracranial infection, are not easy to be differentiated during early-onset lacking the detection of autoantibody.

METHODS

In our single-center cohorts, those patients mimicking intracranial infection as initial symptoms, including 9 with A-GFAP-A, 17 with MOGAD and 11 with AQP4-IgG⁺NMOSD, were retrospectively included. The autoantibodies were detected by cell-based assays. The clinical, immunological and radiological characteristics were summarized.

RESULTS

In the cohort, tremor and positive Kernig's sign were predominated in A-GFAP-A (44.4% and 77.8%, respectively) over MOGAD (5.9%, p = 0.034; 29.4%, p = 0.038) and AQP4-IgG⁺NMOSD (0, p = 0.026; 18.2%, p = 0.022). Ten patients (A-GFAP-A, 4; MOGAD, 5; AQP4-IgG⁺NMOSD, 1) were initially misdiagnosed as tubercular or viral meningoencephalitis, however, resistant to empiric anti-tuberculosis or anti-viral treatment, and finally were in partial or complete remission with the immunotherapy when adjusted treatments. On cerebrospinal fluid (CSF) examination, white blood cell counts in CSF was higher in A-GFAP-A cohort (median, 90×10⁶/L [IQR, 41-209]) compared to AQP4-IgG⁺ NMOSD (median, 6 × 10⁶/L [IQR, 1-10], p = 0.018). Importantly, the higher increase in CSF protein (1319 mg/L [IQR, 1035-1519]), lactate dehydrogenase (LDH, 53.9 ± 37.2 U/L), lactic acid (3.50 ± 0.88 mmol/L), IgG (130.9 ± 60.4 mg/L), IgM (8.6 ± 6.1 mg/L) and IgA (23.0 ± 11.4 mg/L) levels in A-GFAP-A was found compared to MOGAD (CSF protein: 441 mg/L [IQR, 330-776], p = 0.004; LDH: 53.9  ±  37.2 U/L, p = 0.005; lactic acid: 2.15 ± 0.62 mmol/L, p = 0.001; IgG: 77.9 ± 71.3 mg/L, p = 0.018; IgM, 2.7 ± 2.9 mg/L, p = 0.015) and AQP4-IgG⁺ NMOSD (CSF protein: 386 mg/L [IQR, 369-453], p = 0.002; LDH: 23.7 ± 11.0 U/L, p = 0.048; lactic acid: 2.40  ±  0.66 mmol/L, p = 0.040; IgG, 53.2 ± 30.3 mg/L, p = 0.015; IgM, 2.1 ± 3.9 mg/L, p = 0.004; IgA, 5.2 ± 5.0 mg/L, p < 0.001). Of Note, smaller (< 2 cm), symmetrical lesions in ganglia and thalamus (5/8, 62.5%) were showed in over half of the A-GFAP-A patients (5/8, 62.5%), but never in MOGAD (0%, p = 0.001) and AQP4-IgG⁺NMOSD (0%, p = 0.026). In addition, diffuse meningeal enhancement was more common in A-GFAP-A (8, 88.9%) compared to MOGAD (5, 29.4%, p = 0.011) and AQP4-IgG⁺NMOSD (1/6, 16.7%, p = 0.011), respectively. Acute disseminated encephalomyelitis (ADEM) -like lesions occurred more frequently in MOGAD (6/16, 37.5%) but never in A-GFAP-A and AQP4-IgG⁺NMOSD (p = 0.02).

CONCLUSION

Our study demonstrates that several distinct features including the symptom of tremor, higher CSF immunological profiles, bilateral symmetrical lesions in ganglia, and diffuse meningeal enhancement are frequent in A-GFAP-A, whereas ADEM-like lesions seem to occur mainly in MOGAD. These signs provide crucial clinical implications in differential diagnosis for those mimicking intracranial infection as initial symptoms. Clinicians should consider the possibility of these autoimmune CNS inflammatory diseases masquerading as intracranial infection.

Clinical, neuroradiological, diagnostic and prognostic profile of autoimmune glial fibrillary acidic protein astrocytopathy: A pooled analysis of 324 cases from published data and a single-center retrospective study

Autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy is a recently defined autoimmune meningoencephalomyelitis, associated with GFAP-IgG antibody. A pooled analysis of 324 cases from published literature and a retrospective single-center study were performed, firstly reveals the possibility that patients with myelitic lesions respond better to initial immunotherapy, but are prone to relapse, suggesting a more aggressive and long-term immunosuppressive medication for them. Moreover, our results showed using tacrolimus at maintenance stage exhibited a less tendency to relapse, providing a possibly new choice to future clinical treatments.

Meningitis as a recurrent manifestation of anti-AQP4/anti-MOG negative neuromyelitis optica spectrum disorder: a case report

Background

Neuromyelitis optica spectrum disorders (NMOSD), a group of autoimmune neurological diseases, involve the optic nerve, spinal cord, and brain. Meningitis is rarely reported as the primary clinical manifestation of both anti-aquaporin-4 (AQP4)/ anti-myelin oligodendrocyte glycoprotein (MOG) antibody-negative NMOSD (NMOSD^neg).

Case presentation

A 30-year-old man initially presented with fever, headache, and neck stiffness. Lumbar puncture revealed mixed cell reaction and decreased glucose levels. As a result, tuberculous meningitis was suspected. After 1 month, the patient developed longitudinally extensive transverse myelitis and area postrema syndrome. This was followed by the presentation of meningitis-like symptoms once again in the third attack, but his condition eventually improved after corticosteroid treatment without relapse for 2 years. However, he was readmitted to our hospital owing to symptoms of diplopia, hiccup, and numbness in the right hand. Brain magnetic resonance imaging (MRI) revealed that the area postrema still contained lesions. Spinal MRI revealed several segmental enhancements at the C4–C5, T1, and T5 levels. Anti-AQP4 and anti-MOG antibodies were persistently absent in the serum and cerebrospinal fluid (CSF). The patient was finally diagnosed with NMOSD^neg.

Conclusions

Meningitis could be a recurrent manifestation of NMOSD^neg and requires more careful evaluation.