Neuropsychiatric Systemic Lupus Erythematosus: Molecules Involved in Its Imunopathogenesis, Clinical Features, and Treatment

Systemic lupus erythematosus (SLE) is an idiopathic chronic autoimmune disease that can affect any organ in the body, including the neurological system. Multiple factors, such as environmental (infections), genetic (many HLA alleles including DR2 and DR3, and genes including C4), and immunological influences on self-antigens, such as nuclear antigens, lead to the formation of multiple autoantibodies that cause deleterious damage to bodily tissues and organs. The production of autoantibodies, such as anti-dsDNA, anti-SS(A), anti-SS(B), anti-Smith, and anti-neuronal DNA are characteristic features of this disease. This autoimmune disease results from a failure of the mechanisms responsible for maintaining self-tolerance in T cells, B cells, or both. Immune complexes, circulating antibodies, cytokines, and autoreactive T lymphocytes are responsible for tissue injury in this autoimmune disease. The diagnosis of SLE is a rheumatological challenge despite the availability of clinical criteria. NPSLE was previously referred to as lupus cerebritis or lupus sclerosis. However, these terms are no longer recommended because there is no definitive pathological cause for the neuropsychiatric manifestations of SLE. Currently, the treatment options are primarily based on symptomatic presentations. These include the use of antipsychotics, antidepressants, and anxiolytic medications for the treatment of psychiatric and mood disorders. Antiepileptic drugs to treat seizures, and immunosuppressants (e.g., corticosteroids, azathioprine, and mycophenolate mofetil), are directed against inflammatory responses along with non-pharmacological interventions.

Molecular characterization of methicillin-resistant Staphylococcus aureus isolates from rural community settings in Trinidad and Tobago

Aims

To determine the virulence and antimicrobial resistant genes in methicillin resistant Staphylococcus aureus isolates recovered from patients attending two rural health centers in Trinidad and Tobago.

Settings and Design

Cross-sectional observational analysis of patients from two local health centers located in communities in northern region of the country.

Materials and Methods

Nasal and wound swabs from 300 patients were analyzed using standard and molecular techniques. Multiplex polymerase chain reaction was used to detect 16S rRNA, mec A, Staphylococcal chromosomal cassette SCC mec types, pvl, alpha hemolysin (hla), and Toxic Shock Syndrome Toxin 1 (tst 1) genes. S. aureus ATCC 33591 and Staphylococcus epidermidis ATCC 12228 were used for quality control, respectively.

Results

Over a quarter (26.7%, 80/300) of the surveyed patient's samples grew bacterial isolates of which 45% (36/80) were S. aureus and 44.4% (16/36) were mecA-positive. Majority (62.5%, 10/16) possessed the pvl gene, whereas 25% (4/16) possessed the alpha hemolysin (hla) gene. None of the methicillin-resistant Staphylococcus aureus (MRSA) isolates possessed the tst 1 gene. Also, 18.8% (3/16) isolates possessed both virulence genes, pvl and hla. Although the SCCmec types IV and V were detected, but none of the SCCmec I, II, and III were harbored by the isolates.

Conclusions

SCCmec type IV and the pvl genes were common among the MRSA isolates from the community. The hla gene was found infrequently, but none of the isolates possessed the tst 1 gene. Knowledge of this is important for robust surveillance of such cases from the community in the country.