Isolated Acute Cerebrovascular Involvement in COVID-19 without Fever and Respiratory Symptoms: An Indian Perspective.

BACKGROUND: Stroke in COVID-19 has been reported in critically ill patients globally. Stroke as a singular manifestation of COVID-19 in absence of typical symptoms (fever, cough and dyspnea) is under- recognized. OBJECTIVE: Comparative study of clinical and laboratory parameters of COVID-19 stroke patients without typical symptoms at onset with stroke cases without COVID-19 infection. METHODS: 28consecutive stroke patients, eight with coronavirus infection and twenty without COVID-19 admitted to neurology department of a tertiary care centre of North West India between 20 June,2020 and 19 July,2020 were enrolled in this retrospective study. RESULTS: COVID-19 patients had higher frequency of seizures (4[50%]) vs 2[10%];p= 0.03)and altered mental status(6[75%] vs 6[30%] p= 0.04). Severity of ischemic stroke(NIHSS >20, 3[75 %] vs 2[18%])and mortality(p=0.04)despite comparable vascular risk factors for stroke between the two groups was higher in COVID-19 patients. Three out of four COVID-19 young strokes died. Two females with COVID-19 did not develop any typical symptoms, six males(75%) developed fever with dyspnea after a mean delay of 2.7 days(Standard deviation 1.7) from stroke onset. All six patients who developed fever subsequently expired. Inflammatory markers (neutrophil to lymphocyte ratio;p<0.001and ESR: p<0.001), transaminases(p=0.038) and creatinine (p=0.009) were significantly elevated in COVID-19 patients. CONCLUSION: Isolated cerebrovascular involvement can be a presentation of COVID-19.Stroke severity and mortality is higher in COVID-19 with young strokes being no exemption. Development of fever was associated with clinical worsening. COVID-19 pandemic is far from over in India, such atypical presentations need to be recognized early and warrant stringent diagnostic protocols.

Aquaporin 5 regulates cigarette smoke induced emphysema by modulating barrier and immune properties of the epithelium.

Chronic obstructive pulmonary disease (COPD) causes significant morbidity and mortality. Cigarette smoke, the most common risk factor for COPD, induces airway and alveolar epithelial barrier permeability and initiates an innate immune response. Changes in abundance of aquaporin 5 (AQP5), a water channel, can affect epithelial permeability and immune response after cigarette smoke exposure. To determine how AQP5-derived epithelial barrier modulation affects epithelial immune response to cigarette smoke and development of emphysema, WT and AQP5(-/-) mice were exposed to cigarette smoke (CS). We measured alveolar cell counts and differentials, and assessed histology, mean-linear intercept (MLI), and surface-to-volume ratio (S/V) to determine severity of emphysema. We quantified epithelial-derived signaling proteins for neutrophil trafficking, and manipulated AQP5 levels in an alveolar epithelial cell line to determine specific effects on neutrophil transmigration after CS exposure. We assessed paracellular permeability and epithelial turnover in response to CS. In contrast to WT mice, AQP5(-/-) mice exposed to 6 months of CS did not demonstrate a significant increase in MLI or a significant decrease in S/V compared with air-exposed mice, conferring protection against emphysema. After sub-acute (4 weeks) and chronic (6 mo) CS exposure, AQP5(-/-) mice had fewer alveolar neutrophil but similar lung neutrophil numbers as WT mice. The presence of AQP5 in A549 cells, an alveolar epithelial cell line, was associated with increase neutrophil migration after CS exposure. Compared with CS-exposed WT mice, neutrophil ligand (CD11b) and epithelial receptor (ICAM-1) expression were reduced in CS-exposed AQP5(-/-) mice, as was secreted LPS-induced chemokine (LIX), an epithelial-derived neutrophil chemoattractant. CS-exposed AQP5(-/-) mice demonstrated decreased type I pneumocytes and increased type II pneumocytes compared with CS-exposed WT mice suggestive of enhanced epithelial repair. Absence of AQP5 protected against CS-induced emphysema with reduced epithelial permeability, neutrophil migration, and altered epithelial cell turnover which may enhance repair.