Omics-Based Approach Reveals Complement-Mediated Inflammation in Chronic Lymphocytic Inflammation With Pontine Perivascular Enhancement Responsive to Steroids (CLIPPERS)

Unusual CLIPPERS presentation with a predominant spinal cord involvement: case report and review of the literature

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is a discrete nosological entity characterized by punctate and curvilinear gadolinium enhancement "peppering" the pons and a strong response to steroids. MRI images typically show pontine and cerebellar punctate-enhancing lesions, which occasionally spread up to the juxtacortical areas and down to the spinal cord. Interestingly, the more distant the lesion is from the pons, the less intense they become. Herein, we describe an extremely rare case of CLIPPERS presenting with predominant spinal cord involvement; then, we searched in the literature the available cases with a similar presentation. Our case focuses attention on a rare MRI CLIPPERS presentation. Since CLIPPERS has a dramatic response to corticosteroid treatment, it is fundamental to promptly recognize its MRI pattern to start treatment as soon as possible.

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS): contemporary advances and current controversies

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is an inflammatory syndrome with characteristic clinical, radiological, and pathological features, and can be effectively treated with corticosteroid-based immunotherapies. The exact pathogenesis of CLIPPERS remains unclear, and specific diagnostic biomarkers are not available. According to the 2017 diagnostic criteria, probable CLIPPERS should be considered in middle-aged patients with subacute onset of pontocerebellar symptoms and typical punctuate and curvilinear gadolinium enhancement lesions ("salt-and-pepper" appearance) located in the hindbrain (especially pons) on magnetic resonance imaging. In addition, CLIPPERS-mimics, such as central nervous system (CNS) lymphoma, and several antibody-associated autoimmune CNS diseases (e.g., myelin oligodendrocyte glycoprotein antibody-associated disease, autoimmune glial fibrillary acidic protein astrocytopathy, and anti-N-methyl-D-aspartate receptor encephalitis), should be extensively excluded. The prerequisite for definite CLIPPERS is the perivascular T-cell-predominant inflammatory infiltration observed on pathological analysis. A biopsy is strongly suggested when clinical/radiological red flags are present. Most patients with CLIPPERS respond well to corticosteroids and have a good prognosis. Long-term low-dose corticosteroid maintenance therapy or corticosteroids coupled with immunosuppressants are recommended to prevent the recurrence of the syndrome. The potential progression of CLIPPERS to lymphoma has been suggested in some cases; therefore, at least 2-year clinical and radiological follow-up is essential. Here, we critically review the recent developments and provided an update on the clinical characteristics, diagnostic criteria, differential diagnoses, and therapeutic management of CLIPPERS. We also discuss the current controversies in this context that can be resolved in future research studies.

LaCOme: Learning the latent convolutional patterns among transcriptomic features to improve classifications

OMIC is a novel approach that analyses entire genetic or molecular profiles in humans and other organisms. It involves identifying and quantifying biological molecules that contribute to a species' structure, function, and dynamics. Finding the secrets of OMIC is like deciphering the biochemical code, but building data-driven models to mine the hidden phenotypic trait information has been a research hotspot. Transcriptome analysis is a popular biological technology for characterizing living systems' overall health, including cells and tissues. Individual transcript expression levels are known to be correlated with those of other transcripts. Nevertheless, most computational studies do not fully exploit these inter-feature correlations. Differential expression analyses, for example, assume that the expression levels of the transcripts are independent. Thus, we propose extracting these inter-feature correlations using the convolutional neural network (CNN) and transforming the transcriptomic features into a new space of convolutional transcriptomic (LaCOme) features. On most transcriptomic datasets in use, a series of comprehensive experiments have demonstrated that engineered LaCOme features outperform the original transcriptomic features in classification performances. Based on experimental results, OMIC data from biological samples could be further enriched using CNN to enhance computational analysis results. Also, feature rough screening can be used to extract valuable information from OMIC, regardless of the algorithm used to select features. It may always be better to create a novel feature than to keep the original. Furthermore, we investigated the feasibility of the feature construction method through cross-validation and independent verification, hoping to develop a more efficient and effective method.

Multimerin-1 and cancer: a review

Multimerin-1 (MMRN1) is a platelet protein with a role in haemostasis and coagulation. It is also present in endothelial cells (ECs) and the extracellular matrix (ECM), where it may be involved in cell adhesion, but its molecular functions and protein–protein interactions in these cellular locations have not been studied in detail yet. In recent years, MMRN1 has been identified as a differentially expressed gene (DEG) in various cancers and it has been proposed as a possible cancer biomarker. Some evidence suggest that MMRN1 expression is regulated by methylation, protein interactions, and non-coding RNAs (ncRNAs) in different cancers. This raises the questions if a functional role of MMRN1 is being targeted during cancer development, and if MMRN1’s differential expression pattern correlates with cancer progression. As a result, it is timely to review the current state of what is known about MMRN1 to help inform future research into MMRN1’s molecular mechanisms in cancer.

Chronic Lymphocytic Inflammation With Pontine Perivascular Enhancement Responsive to Steroids: An Acute Presentation

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is a rare disease with an unknown etiology which most commonly results in subacute diplopia and ataxia. Diagnosis is achieved through a triad of the following findings: lymphocytic pleocytosis with increased CD4+ T cells on cerebrospinal fluid (CSF) analysis; perivascular punctate and curvilinear hemorrhages in the pons, medulla, or cerebellum on magnetic resonance imaging (MRI) with contrast; and the cessation of symptoms after the initiation of corticosteroids. Here, we report the case of a 23-year-old male who presented with non-specific signs and symptoms, including diffuse weakness in all limbs, ataxia, and slurred speech. The diagnosis was achieved through a contrast MRI of the brain, suggestive of brainstem encephalitis, and a CSF analysis, which revealed elevated glucose and protein levels. Intravenous methylprednisolone was administered for five days and resulted in acute improvement of the patient’s clinical status. Repeat CSF analysis and MRI of the brain with contrast two weeks later showed resolution of previous findings. CLIPPERS syndrome is a newly identified disease thought to cause a predominantly inflammatory reaction in the pons, medulla, cerebellum, and supratentorial region. MRI with contrast tends to reveal a “salt and pepper appearance” in a punctate and curvilinear fashion. The hallmark of treatment is corticosteroid therapy, and discontinuation of therapy should be done with caution as relapse of the syndrome with corticosteroid withdrawal has been documented.

[Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids]

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is an inflammatory disease of the central nervous system, mainly affecting the brain stem, cerebellum and spinal cord. The clinical picture includes gradually developing ataxia, double vision, dysarthria, pyramidal and cognitive impairment. Morphological examination reveals T-cell perivascular lymphocytic infiltration with CD4 lymphocytes predominance over CD8 lymphocytes. The cause of the disease is unknown. The article describes two patients (a 18-year-old woman and a 40-year-old man) with typical clinical and MRI manifestations of CLIPPERS, which was confirmed by brain biopsy in the female patient. The duration of follow-up was 3 and 7 years, respectively. Both patients survived an infection 2-3 weeks before the onset of disease that allows one to discuss its role in CLIPPERS pathogenesis. Both patients had a clear clinical and MRI responsiveness to steroids. In the female patient, steroids were replaced by intramuscular administration of the TNF-α blocker adalimumab. During 1,5 years of its use, there were no clinical relapses and pathological brain changes on MRI.

CLIPPERS, a syndrome of lymphohistiocytic disorders

BACKGROUND

CLIPPERS (chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids) is a chronic central nervous system (CNS) inflammatory disorder. It may be associated with lymphoma and macrophage activation, while the related report of histiocytes (macrophage) activation involved in pathogenesis of CLIPPERS is rare. We present the first "probable CLIPPERS" case associated with histiocytic sarcoma (HS) progressed to hemophagocytic syndrome (HPS) in a 38-year-old man patient.

CASE PRESENTATION

The 38-year-old man presented with facial numbness, diplopia, gait ataxia and glossolalia for 29 months. Brain MRI showed gadolinium enhancement peppering the pons and extending into the midbrain, medulla, brachium pontis, cerebellum and thalamus. The patient's CNS symptoms were improved significantly and accompanied by marked radiological improvement after glucocorticoids therapy, while the disease courses presented relapsing-remitting and glucocorticoids-dependent. Multiple nodules in the abdomen were accidentally discovered by the abdominal Computed tomography (CT) during the remission period. HS was diagnosed by histological examination of the abdominal node biopsy accompanied by CLIPPERS relapse, and eventually progressed to HPS.

CONCLUSIONS

CLIPPERS could be a syndrome of lymphohistiocytic disorders.

CLIPPERS and its mimics: evaluation of new criteria for the diagnosis of CLIPPERS

OBJECTIVE

To evaluate the accuracy of the recently proposed diagnostic criteria for chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS).

METHODS

We enrolled 42 patients with hindbrain punctate and/or linear enhancements (<3 mm in diameter) and tested the CLIPPERS criteria.

RESULTS

After a median follow-up of 50 months (IQR 25-82), 13 out of 42 patients were CLIPPERS-mimics: systemic and central nervous system lymphomas (n=7), primary central nervous system angiitis (n=4) and autoimmune gliopathies (n=2). The sensitivity and specificity of the CLIPPERS criteria were 93% and 69%, respectively. Nodular enhancement ( ≥ 3 mm in diameter), considered as a red flag in CLIPPERS criteria, was present in 4 out of 13 CLIPPERS-mimics but also in 2 out of 29 patients with CLIPPERS, explaining the lack of sensitivity. Four out of 13 CLIPPERS-mimics who initially met the CLIPPERS criteria displayed red flags at the second attack with a median time of 5.5 months (min 3, max 18), explaining the lack of specificity. One of these four patients had antimyelin oligodendrocyte glycoprotein antibodies, and the three remaining patients relapsed despite a daily dose of prednisone/prednisolone ≥ 30 mg and a biopsy targeting atypical enhancing lesions revealed a lymphoma.

CONCLUSIONS

Our study highlights that (1) nodular enhancement should be considered more as an unusual finding than a red flag excluding the diagnosis of CLIPPERS; (2) red flags may occur up to 18 months after disease onset; (3) as opposed to CLIPPERS-mimics, no relapse occurs when the daily dose of prednisone/prednisolone is ≥ 30 mg; and (4) brain biopsy should target an atypical enhancing lesion when non-invasive investigations remain inconclusive.