QCM : Immunosuppressants and Chemotherapy Strategies — 9 questions

Explication

Immunosuppressant classes are categories of drugs that inhibit or reduce the activity of the immune system, used in preventing organ rejection and treating autoimmune diseases. They include corticosteroids, calcineurin inhibitors, antimetabolites, mTOR inhibitors, and monoclonal antibodies, each with distinct mechanisms of action.

Explication

Cyclosporine is a cornerstone calcineurin inhibitor that prevents T-cell activation, essential in transplant immunosuppression. Methotrexate is an antimetabolite, Rituximab is a monoclonal antibody, and Paclitaxel is a mitotic inhibitor.

Explication

Cyclophosphamide is an alkylating agent that adds alkyl groups to DNA bases, leading to cross-linking and strand breaks, which induce apoptosis in cancer cells. Methotrexate is an antimetabolite that inhibits DNA synthesis, Doxorubicin intercalates into DNA and inhibits topoisomerases, and Vincristine inhibits microtubule formation during mitosis.

Explication

mTOR inhibitors like Sirolimus inhibit the mTOR pathway, reducing T-cell proliferation and angiogenesis. They are distinct from corticosteroids and calcineurin inhibitors, which have different mechanisms.

Explication

Lymphocytes are central to the adaptive immune system, with B cells producing antibodies and T cells orchestrating immune responses and killing infected cells. Their main function is to recognize specific antigens and generate targeted, long-lasting immunity, unlike innate immune components that provide immediate, non-specific defense.

Explication

Alkylating agents cause DNA cross-linking by adding alkyl groups, which leads to strand breaks and apoptosis. This mechanism is distinct from antimetabolites, mitotic inhibitors, and intercalators.

Explication

Antimetabolites like Methotrexate mimic natural metabolites and interfere with DNA synthesis during the S phase. Alkylating agents damage DNA generally, while mitotic inhibitors disrupt division, and intercalators obstruct transcription.

Explication

Rituximab specifically targets CD20 on B cells, making it useful in lymphomas and autoimmune diseases. Basiliximab targets IL-2 receptor, Tacrolimus is a calcineurin inhibitor, and Cyclophosphamide is an alkylating agent.

Explication

Nephrotoxicity is a well-known side effect of calcineurin inhibitors such as Tacrolimus and Cyclosporine, requiring careful monitoring during therapy.