Difference between revisions of "Lymphoid system caselets"

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*Flow cytometry
 
*Flow cytometry
 
*Immunomarkers
 
*Immunomarkers
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[[Category:Immunology]] [[Category:Pathology]]

Latest revision as of 07:42, 4 November 2011

Case 1

Mrs. M. S. is a 56 year old female who received an orthotopic liver transplant two weeks ago. Five years prior to transplantation, she had jaundice and pruritis. Liver function tests, performed at the time, showed mild elevation of bilirubin, with striking elevation of the alkaline phosphatase. There was moderate elevation of serum transaminase and elevated serum IgM. The diagnosis of primary biliary cirrhosis (PBC) was considered and the patient's serum was tested for antimitochondrial antibodies and found positive. A liver biopsy showed classic features of PBV with presence of chronic inflammatory infiltrates around bile ducts in the portal tracts, as well as non necrotizing granulomas.

She was treated symptomatically, but her condition was deteriorating over the years; she developed portal hypertension, ascites and encephalopathy. A liver biopsy confirmed liver cirrhosis.

The patient was put on the transplant list and received an orthotopic liver transplant. The surgery went well with no complications. Cyclosporin A, and the monoclonal antibody, OKT3, were received by the patient. Postoperatively, the patient's condition was stable. However, two weeks after, her liver enzymes were elevated. A liver biopsy was performed. The pathologist was immediately contacted to have the biopsy rapidly processed and reported.

What do you think the patient might have?

  • The patient is rejecting the organ (acute rejection)

What is a granuloma?

  • An organized collection of histiocytes
  • Could be necrotizing or non-necrotizing granulomas
  • Infectious diseases (especially Tb) are the most common cause of granulomas
  • In non-infectious diseases, a foreign body (that is not alive) is the cause


How can the pathologist be helpful to the clinicians in this situation?

  • Buy lunch
  • Try to identify if it's actually rejection or something else that they're vulnerable for

What are the different subtypes of hypersensitivity reactions?

  1. Type I: Anaphylactic hypersensitivity
  2. Type II: Antibody-dependent cytotoxic hypersensitivity
  3. Type III: Immune complex mediated hypersensitivity
  4. Type IV: Cell-mediated (delayed-type) hypersensitivity
  5. Type V: Stimulatory hypersensitivity

Explain the mechanism of liver injury in this case

What are the cell types seen in acute rejection?

  • T Cells (CD4/helper and CD8/cytotoxic)

How can acute rejection be treated?

  • more immunosuppression (i.e., increased dose)
  • Drastic increases of immunosuppression result in more opportunistic infections

What are the common types of infection that can be seen in patients taking immunosuppressive drugs?

  • Pneumonias
  • Tuberculosis
  • Viral more common than bacterial
  • Similar to AIDS patients (but not exact)

What are the main dangers after transplantation?

  • Rejection
  • Infection
  • Recurrence of original disease
  • post-transplant lymphoproliferative disorder; PTLPD (e.g., lymphomas)

What role do flow cytometric studies play as follow up in treating patients with acute rejection?

  • The study of cells that distinguishes between B Cells and T cells
  • This patient will show more T cells

Case 2

A 55 year old female presented to her family physician with weakness, fatigue, and shortness of breath. In addition, she had weight loss of 8 lb within the last six months, night sweats and fever. The patient was known to have active connective tissue disease (systematic lupus erythematosus) for the last 15 years, which required a long term, low maintenance dose of corticosteroid.

On examination, she was found to be pale, thin, and short of breath. The cervical and axillary lymph nodes were enlarged. There was mild hepatosplenomegaly as well.

The family physician ordered several tests, including CBC

What are your differential diagnoses?

  • It is probably due to the immunosuppression (the low-dose corticosteroid)
  • The differential diagnosis should account for the minor immunosuppression and SLE

What are the tests that should be ordered?

Chest X-Ray

  • Look for tubercles (as with tuberculosis)
  • Hints at whether the lung involvement is localized or diffuse

Complete blood count (CBC)

  • tells if there is an elevated white cell count
  • Shows if there is neutrophilia

Lymph node FNA or biopsy

  • If lymphoma is not suspected, then FNA is more desired

Mantaux (tuberculin) test

  • Causes Type IV hypersensitivity reaction in 48 - 72 hours

Define anemia

  • See Anemia entry
  • Lack of oxygen-carrying capacity due to decreased hemoglobin
  • Could be due to red cell mass or a hemoglobin problem

Explain its pathogenesis in this patient

  • As part of SLE, the patient is prone to anemia
  • Causes weakness and fatigue (and maybe even shortness of breath)

What are the specific tests that may lead you to the proper diagnosis?

  • Mantaux test, lymph node biopsy and chest X-Ray

List some of the indications for lymph node biopsies and their diagnostic potentials

  • Enlarged lymph nodes
  • FNA (less invasive) does not show a complete picture of the architecture, but in biopsies, it is.

Case 3

An anxious mother of a five year old healthy young girl visited her family physician due to presence of a "lump" in her daughter's right neck. The mother stated that her child never complained of any pain related to the lump. She could not recall any fever, weight loss or decrease of general activities. However, she remembered that her daughter had a flu-like illness two weeks prior to her visit.

On examination, the child had localized lymphadenopathy of the right cervical nodes. The nodes were soft, mobile and non-tender. There was no evidence of any other lymphadenopathy or hepatosplenomegaly. The family physician preferred the "watch and wait" approach for two weeks.

On re-visit, the lymphadenopathy had lessened, but had not disappeared completely. The mother was greatly concerned, therefore the family physician referred the patient to a surgeon. An excisional biopsy was undertaken.

Ten days after the surgery, the mother was told that the condition was benign, called "follicular hyperplasia".

Are there any additional questions that you should ask the mother about?

  • Pets, other skin lesions, etc

What are your differential diagnoses?

  • Reactive hyperplasia (reactive enlargement that is benign)
  • Some other infection
  • Malignancy (such as leukemia)

Which lesions are more common, benign or malignant?

  • Benign

How should the physician handle a lymph node biopsy?

  • Fill out a form
  • Fill in patient details and clinical history
  • Do not fix in formalin

What are the ancillary studies that can be performed in the pathology lab?

  • Cytogenetics
  • Flow cytometry
  • Immunomarkers