Marzia Puccioni-Sohler

Background and Objectives: HTLV-1-associated myelopathy (HAM) is a chronic progressive inflammatory disease of the spinal cord. This study assesses the diagnostic accuracy of the neuroinflammatory biomarkers neopterin and cysteine-X-cysteine motif chemokine ligand 10 (CXCL-10) in cerebrospinal fluid (CSF) for HAM. Methods: CSF samples from 75 patients with neurological disorders—33 with HAM (Group A), 19 HTLV-1-seronegative with other neuroinflammatory diseases (Group B), and 23 HTLV-1-seronegative with non-neuroinflammatory diseases (Group C)—were retrospectively evaluated. CSF examination included routine analysis, neopterin, and CXCL-10. The diagnostic potential of the biomarkers was evaluated using receiver operating characteristic curves. Results: Higher white cell counts and concentrations of protein, neopterin, and CXCL-10 in CSF were detected in group A (patients with HAM) and group B (p < 0.05). Neopterin showed good accuracy for HAM (A) (cut-off 15 nmol/L, 80% sensitivity, 74% specificity) and other neuroinflammation (group B) (cut-off 20 nmol/L, 79% sensitivity, 83% specificity). CXCL-10 demonstrated the highest accuracy in both groups, with Group A (cut-off 110 pg/mL, 97% sensitivity, 96% specificity) and Group B (cut-off 220 pg/mL, 100% sensitivity, 100% specificity). Conclusions: Neopterin and CXCL-10 in CSF are accurate biomarkers for detecting neuroinflammation, including HAM. CXCL-10, in particular, is the superior biomarker for both chronic and acute neuroinflammatory diseases.

Dengue is the main urban arbovirus in the Americas. The disease manifests in a varied spectrum: from asymptomatic cases to those with neurological involvement, which is considered a severe form of the disease. Its annual reemergence represents a serious public health problem. The rise in the number of cases causes an increase in the number of patients with neurological manifestations of the disease, which can range from headaches to more serious conditions such as encephalitis and Guillain-Barré syndrome, with high potential of death or sequelae. Dengue prevention and control strategies should also be a concern for neurologists. The aim of the present study is to carry out a narrative review of the current methods to prevent dengue fever and its severe forms, such as cases with neurological complications. The main control measures include vaccination, which is still carried out on a small scale, vector control, and individual protection. The CYD-TDV/Dengvaxia and TAK-003/DENVax vaccines, licensed for use by the Brazilian National Health Regulatory Agency (Agência Nacional de Vigilância Sanitária, ANVISA, in Portuguese), show efficacy against hospitalizations of 72.7% (95% confidence interval [95%CI]: 62.3–80.3%) and of 90.4% (95%CI: 82.6–94.7%) respectively. The TV003/TV005 vaccine, which is being studied by Intituto Butantan in Brazil, shows promising results, with an efficacy of 79.6% for symptomatic dengue. Vector control is based on biotechnological and behavioral measures, as well as on the improvement of basic sanitation conditions. The main individual protection measure is the use of topical repellents (icaridin). All of these actions represent important tools for the prevention of dengue fever and its neurological complications.

Neurological involvement has been widely reported in SARS-CoV-2 infection. However, viral identification in the cerebrospinal fluid (CSF) is rarely found. The aim of this study is to evaluate the accuracy of virological and immunological biomarkers in CSF for the diagnosis of neuroCOVID-19. We analyzed 69 CSF samples from patients with neurological manifestations: 14 with suspected/confirmed COVID-19, with 5 additional serial CSF samples (group A), and as a control, 50 non-COVID-19 cases (group B—26 with other neuroinflammatory diseases; group C—24 with non-inflammatory diseases). Real-time reverse-transcription polymerase chain reaction (real-time RT-PCR) was used to determine SARS-CoV-2, and specific IgG, IgM, neopterin, and protein 10 induced by gamma interferon (CXCL-10) were evaluated in the CSF samples. No samples were amplified for SARS-CoV-2 by real-time RT-PCR. The sensitivity levels of anti-SARS-CoV-2 IgG and IgM were 50% and 14.28%, respectively, with 100% specificity for both tests. CXCL-10 showed high sensitivity (95.83%) and specificity (95.83%) for detection of neuroinflammation. Serial CSF analysis showed an association between the neuroinflammatory biomarkers and outcome (death and hospital discharge) in two cases (meningoencephalitis and rhombencephalitis). The detection of SARS-CoV-2 RNA and specific immunoglobulins in the CSF can be used for neuroCOVID-19 confirmation. Additionally, CXCL-10 in the CSF may contribute to the diagnosis and monitoring of neuroCOVID-19.

Dengue, zika, and chikungunya are arboviruses of great epidemiological relevance worldwide. The emergence and re-emergence of viral infections transmitted by mosquitoes constitute a serious human public health problem. The neurological manifestations caused by these viruses have a high potential for death or sequelae. The complications that occur in the nervous system associated with arboviruses can be a challenge for diagnosis and treatment. In endemic areas, suspected cases should include acute encephalitis, myelitis, encephalomyelitis, polyradiculoneuritis, and/or other syndromes of the central or peripheral nervous system, in the absence of a known explanation. The confirmation diagnosis is based on viral (isolation or RT-PCR) or antigens detection in tissues, blood, cerebrospinal fluid, or other body fluids, increase in IgG antibody titers between paired serum samples, specific IgM antibody in cerebrospinal fluid and serological conversion to IgM between paired serum samples (non-reactive in the acute phase and reactive in the convalescent). The cerebrospinal fluid examination can demonstrate: 1. etiological agent; 2. inflammatory reaction or protein-cytological dissociation depending on the neurological condition; 3. specific IgM, 4. intrathecal synthesis of specific IgG (dengue and chikungunya); 5. exclusion of other infectious agents. The treatment of neurological complications aims to improve the symptoms, while the vaccine represents the great hope for the control and prevention of neuroinvasive arboviruses. This narrative review summarizes the updated epidemiology, general features, neuropathogenesis, and neurological manifestations associated with dengue, zika, and chikungunya infection.

The impact of coronavirus disease 2019 (COVID-19) on people living with human T-cell leukemia virus type 1 (HTLV-1) is unknown. The aim of this study is to evaluate the COVID-19 risk factors and outcomes of HTLV-1-infected individuals. A retrospective study of seropositive HTLV-1 outpatients seen during the COVID-19 pandemic period (2020–2022) was conducted in a Tertiary Hospital in Rio de Janeiro, Brazil. We compared the demographic and comorbidity/risk factors in patients with COVID-19 and non-COVID-19 diagnoses. In addition, the clinical features of COVID-19 and vaccination status were also investigated in 51 HTLV-1-infected individuals. The majority (88.2%) had COVID-19 comorbidity/risk factors. Seven cases were vaccinated against COVID-19. Overall, 19 out of 51 (37.3%) individuals were diagnosed with COVID-19. We found differences only in the frequency of anxiety in both groups: 57.9% in the COVID-19 group vs. 15.6% in the non-COVID-19 (p < 0.05) group. Thirteen out of nineteen (68%) of the COVID-19 cases progressed to mild/moderate illness, one remained asymptomatic, and 26.3% progressed to severe illness. All of the individuals recovered at home, but the majority (57.9%) developed post-COVID-19 symptoms: anosmia and ageusia (31.6%), worsening anxiety (15.8%), and a feeling of pain in the legs (15.8%). The patients with post-COVID-19 conditions were unvaccinated. Our findings show that HTLV-1 did not increase the risk of lethal COVID-19 and underline the importance of promoting mental health in HTLV-1-infected individuals.

The origin of brain white matter lesion found in HTLV-1-associated myelopathy (HAM/TSP) remains undefined. We investigated the association between white matter lesions in HAM/TSP with cardiovascular risk factors. The group of 40 patients with HAM/TSP included 60% females and mean age of 58.6 ± 8 years old. The probability of 10-year cardiovascular disease was low in 53%, moderate in 38%, and high in 10% of the patients. There was no difference between the cardiovascular risk factors in HAM/TSP patients with and without brain lesions (p > 0.05). Our data suggest that the brain white matter abnormalities are not associated to increased cardiovascular risk in HAM/TSP.

Dengue (DENV) and chikungunya viruses (CHIKV) cause severe neurological complications, sometimes undiagnosed. Therefore, the use of more accessible neuroinflammatory biomarkers can be advantageous considering their diagnostic and prognostic potential for aggravated clinical outcomes. In this study, we aimed to evaluate neopterin and C-X-C motif chemokine ligand 10 (CXCL-10) in cerebrospinal fluid (CSF) for the diagnosis of neuroinvasive DENV and CHIKV. We analyzed the CSF of 66 patients with neurological disorders, comprising 12 neuroinvasive DENV/CHIKV, 20 inflammatory control (viral, bacterial, and fungal meningitis, and autoimmune disorders), and 24 noninflammatory control (cerebrovascular disease, dementia, neoplasm). There was no difference between the concentration of CSF neopterin in the neuroinvasive DENV/CHIKV and control groups. However, there was a significant difference in the CXCL-10 level when comparing the neuroinvasive DENV/CHIKV group and the non-inflammatory control (p < 0.05). Furthermore, we found a linear correlation between neopterin and CXCL-10 CSF levels in the three groups. For the DENV/CHIKV neuroinvasive diagnosis, the ROC curve showed the best cut-off values for CSF neopterin at 11.23 nmol/L (sensitivity of 67% and specificity of 63%), and for CSF CXCL-10 at 156.5 pg/mL (91.7% sensitivity and specificity). These results show that CXCL-10 in CSF represents an accurate neuroinflammatory biomarker that may contribute to neuroinvasive DENV/CHIKV diagnosis.

The association between high proviral load (PVL) in peripheral blood mononuclear cells (PBMC), cognitive disturbance and white matter brain lesions in HTLV-1-infected individuals is still undefined. A cross-sectional study included 62 participants: 22 asymptomatic carriers (mean age 43.4 ± 13.1 years old), 22 patients with HTLV-1-associated myelopathy (HAM/TSP) (mean age 51.5 ± 8.7 years old), and 18 uninfected controls (mean age 52.3 ± 11.1 years old). All individuals fulfilled the following criteria: between 18 and 65 years of age, more than 4 years of formal education, and completed neuropsychological evaluation and HTLV-1 serology. Infected individuals underwent brain conventional magnetic resonance imaging and PVL quantitative PCR (qPCR). Statistical analysis was adjusted in the models by age and education. Cognitive deficit was observed in all groups. Patients with HAM/TSP showed higher neurocognitive deviation in attention and motor skills, higher frequency (84%) of brain white matter lesions, and higher PVL median (range) 8.45 (0.5–71.4) copies/100 PBMC. Brain white matter lesion was associated with verbal memory deficit in HTLV-1-infected individuals (HAM/TSP and asymptomatic carriers) (p = 0.026). In addition, there was a correlation between higher PVL and neurocognitive dysfunction score (processing speed of visuomotor information and visuoconstructive praxis) in HTLV-1-infected patients. The study demonstrates an association between HTLV-1 infection, neurocognitive disorder, and white matter brain lesions on MRI as well as a correlation with higher HTLV-1 PVL, suggesting that the central nervous system involvement by HTLV-1 is not restricted to the spinal cord but involves the whole neuro-axis. HTLV-1-infected individuals should be tested for cognitive impairment.