Case Report: Malignant Melanoma Associated With COVID-19: A Coincidence or a Clue?

Following SARS-CoV-2 infection in humans, there is upregulation of proinflammatory molecules S100 calcium binding protein B (S100B), high-mobility group box-1 (HMGB1), osteopontin (OPN), tumor necrosis factor alpha (TNF-α), and other cytokines that promote hyperinflammation. The same immunoregulatory proteins that fuel the COVID-19 "cytokine storm" are also produced by melanoma cells and various other cancers to promote tumorigenesis. We report three cases of malignant melanoma (MM) associated with severe COVID-19, the first two with amelanotic melanoma and the third with hypopigmented melanoma. It is noteworthy that we did not search for these cases. Patient 1 is a personal acquaintance and cases 2 and 3 were hospitalized and worked at our rehabilitation center, respectively. We hypothesize that SARS-CoV-2 induced inflammatory tumorigenic proteins in the microenvironment that may have contributed to the de novo development (case 1), aggressive growth (case 2), or recurrence (case 3) of these malignant tumors. Moreover, high concentrations of the same proinflammatory proteins found in the "cytokine storm" associated with COVID-19, including TNF-α, interleukin (IL)-1α, IL-1ß, IL-6, and ferritin, also induce skin depigmentation or hypopigmentation by interfering with tyrosinase synthesis, the enzyme that catalyzes the rate-limiting step of pigmentation. Hence, the marked elevation of the biological effectors that decrease skin pigmentation may also reduce pigmentation in MMs, resulting in amelanotic or hypopigmented lesions. Although it is certainly possible that the occurrence of melanoma following COVID-19 is coincidental, the ability of SARS-CoV-2 to increase expression of proinflammatory and tumorigenic molecules warrants further investigations to determine if there is an association between these disease processes or implications for patients with melanoma or other cancers who develop COVID-19.

Tumor Necrosis Factor-Alpha Signaling May Contribute to Chronic West Nile Virus Post-infectious Proinflammatory State.

Background: West Nile virus (WNV) causes a spectrum of human disease ranging from a febrile illness (WNV fever) to severe neuroinvasive disease (meningitis, encephalitis, acute flaccid paralysis). Since WNV gained entry into North America in 1999, clinicians caring for WNV survivors have observed persistent neurological symptoms occurring long-after the production of neutralizing antibodies and clearance of the virus. Accordingly, alternative pathogeneses other than direct viral invasion have been hypothesized to explain these post-infectious symptoms. The dominant hypothesis is that antiviral inflammatory responses triggered initially to clear WNV may persist to promote a post-infectious proinflammatory state. Methods: In 4 serologically-confirmed WNV patients with persistent post-infectious symptoms (3 WNV fever, 1 neuroinvasive disease), we ordered a comprehensive cytokine panel at weeks 8, 10, 12, and 36 months post-onset of illness, respectively, to better understand the pathophysiology of the protracted symptoms. Results: All patients had abnormally elevated tumor necrosis factor alpha (TNF-α), a major molecule triggering antiviral cytokines and chronic inflammation in many human autoimmune diseases, but heretofore not reported to be upregulated in human WNV infection. Three patients also had elevations of other proinflammatory proteins. Major symptoms included fatigue, arthralgias, myalgias, generalized or multifocal pain or weakness, imbalance, headaches, cognitive problems, and symptoms of dysautonomia. Conclusion: The findings provide support for an extended post-infectious proinflammatory state that may contribute to chronic inflammation and long-term morbidity in some WNV survivors and further suggest that TNF-α may play a pathogenic role in initiating this inflammatory environment. Clinical trials may be warranted to determine if TNF-α inhibitors or other immunosuppressive agents can improve patient outcomes.

Current Understanding of West Nile Virus Clinical Manifestations, Immune Responses, Neuroinvasion, and Immunotherapeutic Implications.

West Nile virus (WNV) is the most common mosquito-borne virus in North America. WNV-associated neuroinvasive disease affects all ages, although elderly and immunocompromised individuals are particularly at risk. WNV neuroinvasive disease has killed over 2300 Americans since WNV entered into the United States in the New York City outbreak of 1999. Despite 20 years of intensive laboratory and clinical research, there are still no approved vaccines or antivirals available for human use. However, rapid progress has been made in both understanding the pathogenesis of WNV and treatment in clinical practices. This review summarizes our current understanding of WNV infection in terms of human clinical manifestations, host immune responses, neuroinvasion, and therapeutic interventions.

Exteroceptive suppression of voluntary activity in thenar muscles by cutaneous stimulation: How many trials should be averaged?

OBJECTIVE: To determine a minimum number of trials that preserve input-output (I-O) properties of duration and magnitude of exteroceptive EMG suppression (eEMGs). PATIENTS AND METHODS: eEMGs was recorded in 16 healthy subjects from thenar muscles following index finger stimulation at 2.5, 5, 10, and 20 times sensory threshold (xST). Individual trials were rectified and incrementally averaged in blocks of 5, 10, 20, 30, 40, 50, and 60. To determine if the block size affects I-O properties, the goodness of curve fit parameter R2 for each block was compared to R2 of the global function across all blocks combined. RESULTS: eEMGs was found in all subjects at 10xST and 20xST (100%, respectively) but less often at 5xST (63-75%) and 2.5xST (25-56%). A quadratic function best described both duration and magnitude of eEMGs. The quadratic R2 did not significantly differ between any individual block function (5-60) and the global function (eEMGs duration 0.647-0.704 vs 0.679; magnitude 0.525-0.602 vs 0.560, respectively). CONCLUSIONS: Averaging 5 trials consistently shows eEMGs at and above 10xST. I-O properties of eEMGs do not differ whether 5 or up to 60 trials are averaged. Clinical studies of eEMGs in thenar muscles are possible with as few as 5 trials averaged.

Malignant Glial Neuronal Tumors After West Nile Virus Neuroinvasive Disease: A Coincidence or a Clue?

Following acute West Nile virus (WNV) infection in humans, there is upregulation of pro-inflammatory molecules that promote neuroinflammation, including S100 calcium binding protein B (S100B), high-mobility group box-1 (HMGB1), and osteopontin (OPN). The effects of S100B and HMGB1 are transduced by the receptor for advanced glycation end products (RAGE). Interestingly, the same immunoregulatory proteins that fuel neuroinflammation can also promote tumorigenesis. We present 2 cases of glial neuronal tumors, a glioblastoma multiforme and dysembryoplastic neuroepithelial tumor, in patients with severe West Nile neuroinvasive disease (WNND). In these cases, the viral infection was a precursor to the development of the aggressive brain tumors. We describe a potential mechanism where the presence of tumorigenic proteins in the microenvironment induced by WNV, and subsequent RAGE and OPN signaling, may contribute to development or aggressive growth of these tumors. Although it is certainly possible that the occurrence of primary brain tumors following WNND is coincidental, the ability of WNV to alter cellular signaling and increase expression of pro-inflammatory and tumorigenic molecules merits further investigations to determine whether there is an association between these disease processes or implications for brain tumor patients who develop WNV infection.

Lazarus Effect of High Dose Corticosteroids in a Patient With West Nile Virus Encephalitis: A Coincidence or a Clue?

West Nile virus (WNV) causes severe neuroinvasive disease in humans characterized by meningitis, encephalitis, and acute flaccid paralysis (poliomyelitis variant). In neuroinvasive disease, WNV infection of neurons resulting in neuronal loss is generally presumed to be the anatomical substrate for the high morbidity and mortality. However, on a molecular level, WNV infection also results in a significant upregulation of important proinflammatory molecules that have been reported to promote neuroinflammation and cytotoxicity. Currently, there is no specific treatment for the neurological complications of WNV infection. We present a 71-year-old woman who developed WNV infection that rapidly progressed to severe generalized weakness and encephalitis manifesting with bulbar signs (dysphagia, dysarthria) and persistent delirium and stupor. Consciousness remained impaired for 9 days and then she received a 5-day course of high-dose intravenous methylprednisolone (1,000 mg daily). After the first day, voluntary movement and spontaneous eye-opening increased and by the end of the second day, she was awake and responding to commands. Thereafter, she remained awake and responsive. Although the rapid improvement from stupor to wakefulness following treatment with an anti-inflammatory immunosuppressant could merely be coincidence, since these observations are of one patient, it may also provide a clue that in some cases of WNV neuroinvasive disease a post-infectious pro-inflammatory state, rather than neuronal loss, may also contribute to morbidity. Further clinical trials are warranted to determine if high dose corticosteroids and other drugs that can alter this neuro-inflammatory cascade may be potentially beneficial in the treatment of WNV neuroinvasive disease.

Cutaneous silent periods - Part 2: Update on pathophysiology and clinical utility.

Testing of exteroceptive electromyographic modulation of ongoing voluntary muscle activity is of increasing interest as a diagnostic tool in clinical neurophysiology. The cutaneous silent period (CSP) is a robust and reproducible nociceptive EMG suppression, mediated at the spinal level by small-diameter A-delta afferents. The techniques and physiological principles of CSP testing, which are a fundamental prerequisite for a valid and thoughtful clinical application, are reviewed separately in part 1 (Kofler et al., 2019). This comprehensive review surveys the literature on pathophysiological conditions in which CSPs have been reported, and aims at a critical overview on the clinical utility of CSP testing. The most useful clinical applications seem to be the functional diagnostics of intramedullary, in particular centromedullary, dysfunctions, and the assessment of small fiber neuropathies, in particular those affecting A-delta fibers. CSPs have in addition been studied in a variety of movement disorders and in neuropathic pain and other painful conditions, including fibromyalgia.

Differential Expression of Genes Related to Innate Immune Responses in Ex Vivo Spinal Cord and Cerebellar Slice Cultures Infected with West Nile Virus.

West Nile virus (WNV) infection results in a spectrum of neurological symptoms, ranging from a benign fever to severe WNV neuroinvasive disease with high mortality. Many who recover from WNV neuroinvasive infection present with long-term deficits, including weakness, fatigue, and cognitive problems. While neurons are a main target of WNV, other cell types, especially astrocytes, play an important role in promoting WNV-mediated central nervous system (CNS) damage. Conversely, it has been shown that cultured primary astrocytes secrete high levels of interferons (IFNs) immediately after WNV exposure to protect neighboring astrocytes, as well as neurons. However, how intrinsic responses to WNV in specific cell types and different regions of the brain modify immune protection is not fully understood. Here, we used a mouse ex vivo spinal cord slice culture (SCSC) and cerebellar slice culture (CSC) models to determine the innate immune responses specific to the CNS during WNV infection. Slices were prepared from the spinal cord and cerebellar tissue of 7⁻9-day-old mouse pups. Four-day-old SCSC or CSC were infected with 1 × 10³ or 1 × 105 PFU of WNV, respectively. After 12 h exposure to WNV and 3 days post-infection in normal growth media, the pooled slice cultures were processed for total RNA extraction and for gene expression patterns using mouse Affymetrix arrays. The expression patterns of a number of genes were significantly altered between the mock- and WNV-treated groups, both in the CSCs and SCSCs. However, distinct differences were observed when CSC data were compared with SCSC. CSCs showed robust induction of interferons (IFNs), IFN-stimulated genes (ISGs), and regulatory factors. Some of the antiviral genes related to IFN were upregulated more than 25-fold in CSCs as compared to mock or SCSC. Though SCSCs had twice the number of dysregulated genes, as compared CSCs, they exhibited a much subdued IFN response. In addition, SCSCs showed astrogliosis and upregulation of astrocytic marker genes. In sum, our results suggest that early anti-inflammatory response to WNV infection in CSCs may be due to large population of distinct astrocytic cell types, and lack of those specialized astrocytes in SCSC may make spinal cord cells more susceptible to WNV damage. Further, the understanding of early intrinsic immune response events in WNV-infected ex vivo culture models could help develop potential therapies against WNV.

West Nile virus induces a post-infectious pro-inflammatory state that explains transformation of stable ocular myasthenia gravis to myasthenic crises.

West Nile virus (WNV) infection has been reported to promote myasthenia gravis (MG) and various other diseases that have a presumed autoimmune pathogenesis. Molecular mimicry between WNV proteins and host proteins has been postulated as the major mechanism for WNV-triggered breaking of immunological self-tolerance. We present a patient with stable ocular MG and positive anti-acetylcholine receptor antibodies who progressed to myasthenic crisis after WNV neuroinvasive disease. In this case of stable autoimmune disease with proven auto-antibodies, transformation to generalized disease cannot be attributed to molecular mimicry, which requires that an immune response first be generated against an infectious agent. Rather, the evidence supports the concept of a post-infectious pro-inflammatory state that may contribute to the amplification and promotion of autoimmune disease in some WNV survivors.

Osteopontin facilitates West Nile virus neuroinvasion via neutrophil "Trojan horse" transport.

West Nile virus (WNV) can cause severe human neurological diseases including encephalitis and meningitis. The mechanisms by which WNV enters the central nervous system (CNS) and host-factors that are involved in WNV neuroinvasion are not completely understood. The proinflammatory chemokine osteopontin (OPN) is induced in multiple neuroinflammatory diseases and is responsible for leukocyte recruitment to sites of its expression. In this study, we found that WNV infection induced OPN expression in both human and mouse cells. Interestingly, WNV-infected OPN deficient (Opn -/-) mice exhibited a higher survival rate (70%) than wild type (WT) control mice (30%), suggesting OPN plays a deleterious role in WNV infection. Despite comparable levels of viral load in circulating blood cells and peripheral organs in the two groups, WNV-infected polymorphonuclear neutrophil (PMN) infiltration and viral burden in brain of Opn -/- mice were significantly lower than in WT mice. Importantly, intracerebral administration of recombinant OPN into the brains of Opn -/- mice resulted in increased WNV-infected PMN infiltration and viral burden in the brain, which was coupled to increased mortality. The overall results suggest that OPN facilitates WNV neuroinvasion by recruiting WNV-infected PMNs into the brain.

Pleural "drop metastases" 21 years after resection of a thymoma.

INTRODUCTION: We describe an unusual case of pleural drop metastases 21 years after complete resection of an encapsulated thymoma in a Southeast Asian patient with myasthenia gravis (MG). METHODS: This investigation includes a case report and brief review of the literature. RESULTS: The patient presented in 2015 with generalized weakness, fatigue, and shortness of breath, but no diplopia, ptosis, dysphagia, or dysarthria. Because these symptoms were atypical for an MG exacerbation, a de-novo work-up was performed. Chest computed tomography (CT) showed numerous pleural nodules ("drop metastases"), and CT-guided biopsy revealed metastatic thymoma. CONCLUSIONS: The average disease-free interval for thymoma ranges from 68 to 86 months. Pleural and mediastinal recurrence are more common than distant hematogenous recurrence. Adverse prognostic factors include an initial higher Masaoka stage, incomplete resection, older age, and pleural or pericardial involvement. Despite apparent complete resection of thymoma, clinicians should remain vigilant for recurrence for as long as 20 years after initial management. Long-term follow-up with radiologic surveillance is recommended. Muscle Nerve 56: 171-175, 2017.

Complete dislocation of the ulnar nerve at the elbow: a protective effect against neuropathy?

INTRODUCTION: Recurrent complete ulnar nerve dislocation has been perceived as a risk factor for development of ulnar neuropathy at the elbow (UNE). However, the role of dislocation in the pathogenesis of UNE remains uncertain. METHODS: We studied 133 patients with complete ulnar nerve dislocation to determine whether this condition is a risk factor for UNE. In all, the nerve was palpated as it rolled over the medial epicondyle during elbow flexion. RESULTS: Of 56 elbows with unilateral dislocation, UNE localized contralaterally in 17 elbows (30.4%) and ipsilaterally in 10 elbows (17.9%). Of 154 elbows with bilateral dislocation, 26 had UNE (16.9%). Complete dislocation decreased the odds of having UNE by 44% (odds ratio = 0.475; P = 0.028), and was associated with less severe UNE (P = 0.045). CONCLUSIONS: UNE occurs less frequently and is less severe on the side of complete dislocation. Complete dislocation may have a protective effect on the ulnar nerve. Muscle Nerve 56: 242-246, 2017.

Interleukin-17A Promotes CD8+ T Cell Cytotoxicity To Facilitate West Nile Virus Clearance.

CD8+ T cells are crucial components of immunity and play a vital role in recovery from West Nile virus (WNV) infection. Here, we identify a previously unrecognized function of interleukin-17A (IL-17A) in inducing cytotoxic-mediator gene expression and promoting CD8+ T cell cytotoxicity against WNV infection in mice. We find that IL-17A-deficient (Il17a-/-) mice are more susceptible to WNV infection and develop a higher viral burden than wild-type (WT) mice. Interestingly, the CD8+ T cells isolated from Il17a-/- mice are less cytotoxic and express lower levels of cytotoxic-mediator genes, which can be restored by supplying recombinant IL-17A in vitro and in vivo Importantly, treatment of WNV-infected mice with recombinant IL-17A, as late as day 6 postinfection, significantly reduces the viral burden and increases survival, suggesting a therapeutic potential for IL-17A. In conclusion, we report a novel function of IL-17A in promoting CD8+ T cell cytotoxicity, which may have broad implications in other microbial infections and cancers. IMPORTANCE: Interleukin-17A (IL-17A) and CD8+ T cells regulate diverse immune functions in microbial infections, malignancies, and autoimmune diseases. IL-17A is a proinflammatory cytokine produced by diverse cell types, while CD8+ T cells (known as cytotoxic T cells) are major cells that provide immunity against intracellular pathogens. Previous studies have demonstrated a crucial role of CD8+ T cells in recovery from West Nile virus (WNV) infection. However, the role of IL-17A during WNV infection remains unclear. Here, we demonstrate that IL-17A protects mice from lethal WNV infection by promoting CD8+ T cell-mediated clearance of WNV. In addition, treatment of WNV-infected mice with recombinant IL-17A reduces the viral burden and increases survival of mice, suggesting a potential therapeutic. This novel IL-17A-CD8+ T cell axis may also have broad implications for immunity to other microbial infections and cancers, where CD8+ T cell functions are crucial.

TLR8 Couples SOCS-1 and Restrains TLR7-Mediated Antiviral Immunity, Exacerbating West Nile Virus Infection in Mice.

West Nile virus (WNV) is a neurotropic ssRNA flavivirus that can cause encephalitis, meningitis, and death in humans and mice. Human TLR7 and TLR8 and mouse TLR7 recognize viral ssRNA motifs and induce antiviral immunity. However, the role of mouse TLR8 in antiviral immunity is poorly understood. In this article, we report that TLR8-deficient (Tlr8-/-) mice were resistant to WNV infection compared with wild-type controls. Efficient WNV clearance and moderate susceptibility to WNV-mediated neuronal death in Tlr8-/- mice were attributed to overexpression of Tlr7 and IFN-stimulated gene-56 expression, whereas reduced expression of the proapoptotic gene coding Bcl2-associated X protein was observed. Interestingly, suppressor of cytokine signaling (SOCS)-1 directly associated with TLR8, but not with TLR7, indicating a novel role for TLR8 regulation of SOCS-1 function, whereas selective small interfering RNA knockdown of Socs-1 resulted in induced IFN-stimulated gene-56 and Tlr7 expression following WNV infection. Collectively, we report that TLR8 coupling with SOCS-1 inhibits TLR7-mediated antiviral immunity during WNV infection in mice.

Zika Virus and Guillain-Barre Syndrome: Is There Sufficient Evidence for Causality?

Worldwide concern over Zika virus causing Guillain-Barre syndrome (GBS) soared after recent reports that Zika-related weakness was due to GBS. A global strategic response plan was initiated with recommendations for at-risk countries to prepare for GBS. This plan has major economic implications, as nations with limited resources struggle to implement costly immunotherapy. Since confirmation of causality is prerequisite to providing specific management recommendations, it is prudent to review data endorsing a GBS diagnosis. We searched PubMed for manuscripts reporting original clinical, laboratory, and electrodiagnostic data on Zika virus and GBS. Five papers met criteria; four case reports and one large case-control study (French Polynesia) that attributed 42 paralysis cases to a motor variant of GBS. Brighton criteria were reportedly used to diagnose GBS, but no differential diagnosis was presented, which violates criteria. GBS was characterized by early onset (median 6 days post-viral syndrome), rapid progression (median 6 days from onset to nadir), and atypical clinical features (52% lacked areflexia, 48% of facial palsies were unilateral). Electrodiagnostic evaluations fell short of guidelines endorsed by American Academy of Neurology. Typical anti-ganglioside antibodies in GBS motor variants were rarely present. We conclude that there is no causal relationship between Zika virus and GBS because data failed to confirm GBS and exclude other causes of paralysis. Focus should be redirected at differential diagnosis, proper use of diagnostic criteria, and electrodiagnosis that follows recommended guidelines. We also call for a moratorium on recommendations for at-risk countries to prepare costly immunotherapies directed at GBS.

Concurrent West Nile virus infection in pneumococcal meningitis: clinical and MRI features.

We report the clinical and neuroimaging findings of an immunocompetent patient with concurrent pneumococcal and West Nile virus meningoencephalitis with relapsing clinical course despite a full course of antibiotic treatment. The patient developed acute oculomotor nerve palsy with pupillary involvement and bilateral hearing loss, and delayed right leg monoparesis. We speculate that coexisting bacterial and viral neuroinvasive infections contributed to the unusual clinical and imaging manifestations, and that overwhelming laboratory and clinical features of bacterial meningitis masked the typical features of CNS viral infection. Therefore, atypical presentations of bacterial meningitis should raise a high index of suspicion for coexisting infections, even in immunocompetent patients, and evolving neuroimaging findings may be helpful in substantiating clinical suspicion and guiding further management.

Keep an eye out for myasthenia gravis patients with an eye out.

Eye trauma and blindness are common in the United States, with an incidence of over 2 million cases/year and 25 million blind adults, respectively. However, literature is surprisingly scarce on the potential confounding effect of eye trauma or blindness on the diagnosis of myasthenia gravis (MG), an autoimmune neuromuscular disease in which fluctuating ocular symptoms are the most distinguishing feature. We present the case of a 75-year-old man with eye enucleation referred for electrodiagnostic evaluation of the right upper limb after an accidental fall. Neurological examination showed proximal muscle weakness, but MG was not initially considered because the patient lacked the classic ocular symptoms of MG. The delay in diagnosis resulted in worsening of systemic MG symptoms, although in other patients it may have precipitated MG crisis or possibly death. Greater awareness that eye trauma or blindness can prevent expression of ocular symptoms in neuromuscular disorders is needed to avoid morbidity associated with an erroneous or delayed diagnosis.

West nile virus infection and myasthenia gravis.

INTRODUCTION: Viruses are commonly cited as triggers for autoimmune disease. It is unclear if West Nile virus (WNV) initiates autoimmunity. METHODS: We describe 6 cases of myasthenia gravis (MG) that developed several months after WNV infection. All patients had serologically confirmed WNV neuroinvasive disease. None had evidence of MG before WNV. RESULTS: All patients had stable neurological deficits when they developed new symptoms of MG 3 to 7 months after WNV infection. However, residual deficits from WNV confounded or delayed MG diagnosis. All patients had elevated acetylcholine receptor (AChR) antibodies, and 1 had thymoma. Treatment varied, but 4 patients required acetylcholinesterase inhibitors, multiple immunosuppressive drugs, and intravenous immune globulin or plasmapheresis for recurrent MG crises. CONCLUSIONS: The pathogenic mechanism of MG following WNV remains uncertain. We hypothesize that WNV-triggered autoimmunity breaks immunological self-tolerance to initiate MG, possibly through molecular mimicry between virus antigens and AChR subunits or other autoimmune mechanisms.

Glial S100B is elevated in serum across the spectrum of West Nile virus infection.

INTRODUCTION: We previously reported that protein biomarkers of neuronal death and glial pathology were elevated in the cerebrospinal fluid of patients with West Nile virus (WNV) infection, including WNV fever. Therefore, we hypothesized that the glial biomarker S100B would also be elevated in serum across the spectrum of WNV disease. METHODS: Serum levels of S100B were measured by enzyme-linked immunoassay (ELISA) in 90 WNV patients (35 with neuroinvasive disease and 55 with WNV fever) and compared with 34 healthy controls. RESULTS: Serum S100B was significantly higher in patients (median 0.17 ng/ml) than in controls (0.09 ng/ml, P < 0.0001). Serum S100B was elevated in 16 cases (46%) with neuroinvasive disease and in 19 cases (35%) with WNV fever. CONCLUSIONS: The increase in serum S100B reaffirms pathological changes across the spectrum of WNV disease. The elevated S100B in over one third of WNV fever cases implies that neuroinvasion occurs in a much greater proportion of patients than anticipated by clinical and epidemiological data.