Patho3c - Cdsa-infectious And Autoimmune

SITUATIONAL ANALYSIS TISSUE REACTIONS TO INJURY Part 3: Immune Reactions to Injury

Principles of Infectious Disease, Autoimmune Disease, and Immune Deficiencies Prepared by EMMANUEL R. de la FUENTE, M.D.

Objectives 2. To recognize the patterns of inflammation in the different types of infectious disease 3. To discuss the essential mechanisms of important autoimmune, primary and acquired immunodeficiency diseases 4. To state the essential morphologic features of the above (no. 2)

Principles of Infectious Disease

Different types of infectious disease give different patterns of inflammation and necrosis. These patterns are: 2. Acute inflammation with liquefactive necrosis (pyogenic inflammation) 3. Acute inflammation with coagulative necrosis (which may become purulent later on) 4. Granulomas with or without caseous necrosis 5. Predominantly lymphohistiocytic inflammatory response

Situation No. 1 A 14 year old boy was admitted to a hospital because of dyspnea. Crackles were heard on all lung fields. These were accompanied by fever and cough. Antibiotics were given but his condition worsened; he died four days after admission.

1. State the problem of this case. 2. What are the facts that support your problem statement? 3. Give hypotheses as possible explanations to the problem.

The next set of microscopic pictures shows the different stages of development of the lesions not in chronological order.

Slide no. 1. Identify and describe the lesion. What phase of acute inflammation is seen?

Slide no. 2. Identify and describe the lesion. What phase of acute inflammation is seen?

Slide no. 3. Identify and describe the lesion. What pattern of inflammation and necrosis is seen?

Slide no. 4. Identify and describe the lesion. What pattern of inflammation and necrosis is seen?

1. Arrange now the previous slides into their sequence of development. 2. What biological characteristics do these organisms have that give rise to this pattern of inflammation and necrosis? 3. Correlate these lesions with the clinical situation (final hypothesis).

Identify and describe the gross lesions and correlate with the microscopic lesions.

Situation No. 2 A 67 year old woman who had been diabetic for the past 30 years had persistent fever for the past 3 wks. This was accompanied by chronic cough and difficulty of breathing. The attending physician had suspected pneumonia, and she was given antibacterial chemotherapy which afforded no relief. Sputum culture showed filamentous fungal elements. After a week her pulmonary manifestations became more severe, and further, she developed weakness of the left upper and lower extremities. She died shortly thereafter.

1. State the problem of this case. 2. What are the facts that support your problem statement? 3. Give hypotheses as possible explanations to the problem.

Filamentous fungal elements seen in sputum culture.

This is a silver stain of an arteriole of the brain which stains the fungal elements. Similar lesions are seen in other organs. Identify the organism and predict the consequences.

The lung. Identify and describe the lesion. What type of necrosis do you expect to see? Discuss the pathogenesis of the lesion.

A section of the brain. Identify and describe the lesion. What type of necrosis do you expect to see? Discuss the pathogenesis of the lesion.

1. What type of immune response do you expect to see in this type of infection? 2. Explain why? 3. Correlate these lesions with the clinical situation (final hypothesis).

Situation No. 3 Patient no. 1 is a 3 year old girl who developed signs and symptoms of measles. Four days later, she developed severe dyspnea and died. Patient no. 2 is a neighbor of similar age who also developed measles at approximately the same time. She, however, became well after a week.

1. State the problem of this situation. 2. What are the facts that support your problem statement? 3. Give hypotheses as possible explanations to the problem.

This is a section of the lung of that girl who died. Identify and describe the lesion.

Most areas of the lung show this lesion. Identify and describe the lesion. Identify the lesion in the inset and the structure indicated by the arrow.

1. Discuss the immune response seen in the lung sections. 2. Give possible reasons why numerous giant cells with inclusion bodies are formed. 3. Is this infection caused by a DNA or RNA virus? 4. Give possible explanations why patient no. 1 despite the presence of an immune response died while patient no. 2 lived.

Immune Deficiencies Review the history and immune responses of the 3 previous cases. If the failure of the immune response to neutralize and/or destroy the infectious agent is due to some immune deficiencies, discuss the possible areas of failure of the immune system.

Autoimmune Disease 2.Organ-specific 3.Systemic

Situation No. 1 A 48 year old woman was diagnosed to have Hashimoto’s Disease of the thyroid. Which of the two gross thyroids is consistent with the diagnosis? Describe and explain the gross.

1 cm

1 cm

Microscopic sections. Identify and describe the lesion. What type of immune response is represented by this type of morphology? Explain.

40 x

400 x

Situation No. 2 An 18 year old girl developed erythematous rashes all over her skin. She was diagnosed as a case of lupus erythematosus. Characteristic “butter” rash was seen on her face. A biopsy of her skin lesion was done.

Sections of the skin. Identify and describe the lesion. The arrow indicates an arteriole. Discuss the immune response as manifested by this morphologic pattern.

An immunofluorescence stain with antibody to complement shows the brightly fluorescing band along the dermal epidermal junction (arrow). This indicates the presence of immune complex deposits. Explain this phenomenon.

Transplantation Pathology

Situation No. 1 An allograft transplanted heart rejected by the host. Identify and describe the lesion. Discuss the immune response.

Situation No. 2 An allograft transplanted kidney rejected by the host. Identify and describe the lesion. Discuss the immune response.

The End