Question

immunology clinical case questions:

-While he was in the hospital, SARS-CoV-2 was again detected at days 5–6 in nasopharyngeal, sputum and fecal samples, but was undetectable from day 7. Blood C-reactive protein was elevated at 83.2, with normal counts of lymphocytes and neutrophils. No other respiratory pathogens were detected. His management was intravenous fluid rehydration without supplemental oxygenation. No antibiotics, steroids or antiviral agents were administered. Chest radiography demonstrated bi-basal infiltrates at day 5 that cleared on day 10. He was discharged to home isolation on day 1

During his time at the hospital explain:

1. What is the immunological relevance of the elevated C-reactive protein (CRP)? What is the function of CRP in inflammation?

b.Explain which adaptive humoral immune responses (cells and antibodies) are acting in this patient while he is in the hospital (days 5-10).

c.Explain the role(s) of the activated T cells and molecular effectors. Explain cell-cell interactions and resulting cytokine/chemokine production.

d.Explain how the lungs become cleared on day 10. Which immune mechanisms (effectors) are important to restore homeostasis?

Answer 1

1) CRP is produced by the body in liver when there is inflammation. High amount of CRP indicates the presence of inflammation in body which can be due to some infection of bacteria or virus, autoimmune disorder or cardiovascular disorder. CRP is an acute phase protein which helps in activation of complement system and phagocytosis of pathogen.

2) in the period of 5-10 days B cells were acting like antigen presenting cells which presents the foreign peptide to T cells via MHC molecule which in turn activates the Bcells to produce specific antibodies secreating plasma cells and memory B Cells.

2) there are three types of Tcells

a) helper t cells- these cells recognise the foreign peptide presented by MHC II molecule on APC.( B cells and dendritic cells). they also rapidly divide and secrete cytokines

b) cytotoxic t cells - these cells recognise foreign peptide present on MHC 1 molecule on all nucleated cells. these mainly secrete IL2 AND INF gamma.

c) suppressor t cells - they supress the action t cells and b cells when not needed.

4) lungs become cleared by the combine action of various immune cells which are T cells ,Bcells ,cytokines macrophages etc.