A complex pathophysiological mechanism is involved in brain injury following cerebral infarction. The neurovascular unit (NVU) is a complex multi-cellular structure consisting of neurons, endothelial cells, pericyte, astrocyte, microglia and extracellular matrix, etc. The dyshomeostasis of NVU directly participates in the regulation of inflammatory immune process. The components of NVU promote inflammatory overreaction and synergize with the overactivation of autonomic nervous system to initiate stroke-induced immunodepression (SIID). SIID can alleviate the damage caused by inflammation, however, it also makes stroke patients more susceptible to infection, leading to systemic damage. This article reviews the mechanism of SIID and the roles of NVU in SIID, to provide a perspective for reperfusion, prognosis and immunomodulatory therapy of cerebral infarction.
Humans ; Endothelial Cells ; Stroke ; Neurons/physiology* ; Immunosuppression Therapy/adverse effects* ; Cerebral Infarction

Adult ; Antiviral Agents ; therapeutic use ; Colonic Neoplasms ; diagnosis ; etiology ; therapy ; Cyclosporine ; adverse effects ; Esophageal Neoplasms ; diagnosis ; etiology ; therapy ; Female ; Ganciclovir ; therapeutic use ; Humans ; Immunosuppression ; adverse effects ; Immunosuppressive Agents ; adverse effects ; Liver Neoplasms ; diagnosis ; etiology ; therapy ; Liver Transplantation ; adverse effects ; Lymphoproliferative Disorders ; diagnosis ; etiology ; therapy ; Middle Aged ; Pharyngeal Neoplasms ; diagnosis ; etiology ; therapy ; Survival Analysis ; Tacrolimus ; adverse effects ; Time Factors

A 51-yr-old female was referred to our outpatient clinic for the evaluation of generalized edema. She had been diagnosed with idiopathic thrombocytopenic purpura (ITP). She had taken no medicine. Except for the ITP, she had no history of systemic disease. She was diagnosed with systemic lupus erythematosus. Immunosuppressions consisting of high-dose steroid were started. When preparing the patient for discharge, a generalized myoclonic seizure occurred at the 47th day of admission. At that time, the laboratory and neurology studies showed hyperglycemic hyperosmolar syndrome. Brain MRI and EEG showed brain atrophy without other lesion. The seizure stopped after the blood sugar and serum osmolarity declined below the upper normal limit. The patient became asymptomatic and she was discharged 10 weeks after admission under maintenance therapy with prednisolone, insulin glargine and nateglinide. The patient remained asymptomatic under maintenance therapy with deflazacort and without insulin or medication for blood sugar control.
Edema ; Epilepsies, Myoclonic/complications/drug therapy ; Female ; Humans ; Hyperglycemia/*chemically induced ; Immunosuppression ; Insulin/therapeutic use ; Lupus Nephritis/*complications/drug therapy ; Middle Aged ; Prednisolone/administration & dosage/*adverse effects/therapeutic use ; Purpura, Thrombocytopenic, Idiopathic/complications/*drug therapy

Reactivation of polyoma virus (BK virus) is a significant cause of morbidity in kidney transplant patients. This seemingly insignificant viral infection that affects the majority of population at a young age, once reactivated by immunosuppression, is a major factor contributing to graft loss. Screening techniques have been developed for early prediction of BK virus reactivation. These include plasma and urine assays for detection of BK virus DNA by PCR, urine cytology for detection of "decoy cells" and electron microscopy. Combining urine cytology and serology screening can be more effective for early detection of BK virus reactivation. Immunohistochemistry can be utilized as an additional tool to support the diagnosis. Once screening tests reveal a suspicious BK virus reactivation, tissue biopsy should be performed to confirm the diagnosis, rule out acute cellular rejection and plan treatment approaches. Treatment normally includes decreasing immunosuppression and the use of antiviral drug therapy. Unfortunately, disease outcome is often unfavorable and can culminate with eventual graft loss. Renal retransplantation has been performed with mixed results. As new data emerges, we will gain a better understanding of the disease caused by BK virus and respond with improved early diagnosis and treatment to preserve graft function.
Antiviral Agents/therapeutic use ; *BK Virus ; Humans ; Immunosuppression/*adverse effects ; Kidney Diseases/pathology/*virology ; *Kidney Transplantation ; Polyomavirus Infections/*complications/drug therapy/etiology ; Tumor Virus Infections/*complications/drug therapy/etiology

Infection of the central nervous system with Nocardia sp. usually manifests as supratentorial abscesses. Supratentorial and cerebellar abscesses from infection with Nocardia sp. following immunosuppression with long-term corticosteroids for idiopathic thrombocytopenia (ITP) have not been reported. An 83 years-old, human immunodeficiency virus (HIV)-negative, polymorbid male with ITP for which he required corticosteroids since age 53 years developed tiredness, dyspnoea, hemoptysis, abdominal pain, and progressive gait disturbance. Imaging studies of the lung revealed an enhancing tumour in the right upper lobe with central and peripheral necrosis, multiple irregularly contoured hyperdensities over both lungs, and right-sided pleural effusions. Sputum culture grew Nocardia sp. Neurological diagnostic work-up revealed dysarthria, dysphagia, ptosis, hypoacusis, tremor, dysdiadochokinesia, proximal weakness of the lower limbs, diffuse wasting, and stocking-type sensory disturbances. The neurological deficits were attributed to an abscess in the upper cerebellar vermis, myopathy from corticosteroids, and polyneuropathy. Meropenem for 37 days and trimethoprime-sulfamethoxazole for 3 months resulted in a reduction of the pulmonary, but not the cerebral lesions. Therefore, sultamicillin was begun, but without success. Long-term therapy with corticosteroids for ITP may induce not only steroid myopathy but also immune-incompetence with the development of pulmonary and cerebral nocardiosis. Cerebral nocardiosis may not sufficiently respond to long-term antibiotic therapy why switching to alternative antibiotics or surgery may be necessary.
Adrenal Cortex Hormones/*adverse effects/*therapeutic use ; Aged, 80 and over ; Cerebellar Diseases/*chemically induced/*diagnosis/pathology ; Humans ; Immunosuppression ; Male ; Muscular Diseases/*chemically induced/pathology ; Nocardia Infections/*diagnosis ; Purpura, Thrombocytopenic, Idiopathic/*drug therapy