What are the lymph node structures?
Follicle
Medulla
Paracotex
What is the function of the Follicle of the LN?
Site of B cell localization and prolif
- in out cortex
- 1’ follicles are dense and dormant
- 2’ follicles have pale central germinal centers and are active
What is the function of the medulla of the LN?
Consists of medullar cords and medullar sinuses
- medullary sinus comm with efferent lymphatics and contain reticular cells (Fibroblasts) and macs
What is the medullar cord?
Closely packed lymphocytes and plasma cells
What is the function of paracortex of the LN?
Houses T Cells
- Region of cortex between follicles and medulla
- contains high endothelial venules through which T and B cells enter from blood
- Not well dev in pt with DeGeorge
- enlarges in extreme cellular immune response like viral infection
what is contained in the marginal zones of the spleen?
Macs and specialized B cells and where the APC’s capture blood borne Ags for recognition
What in terms of immune system is deficient in a pt with a splenectomy?
Decreased IgM
Decreased Complement
Decreased C3b
Increased susceptibility of encapsulated organisms
What are the encapsulated organisms we worry about with a person with a splenectomy?
Please SHINE my SKiS Pseudomonas Strep p Haemophilis Influenzae Neisseria m E coli Salmonella** Klebsiella p Group B strep
What is isoniazid?
It is a TB antibiotic
- INH Injures Neurons and Hepatocytes
What process of synthesis can it interfere with?
heme synthesis by B6 deficiency
- one taking Isoniazid should be put on a B6 supplement in the pyridoxine form
- CNS effects, anemia, and peripheral neuropathy
- sideroblastic anemia
Wha is B6 needed for?
Cysthationine heme niacin histamine and 5ht, Epi, NE, DA and GABA
What are the main suspects if you have elevated conjugate (direct)bilirubin?
Biliary obstruction
tumor of liver
What would you suspect if you elevated unconjugated bilirubin?
Haemolysis- the liver can keep up with the degradation of RBC’s and thus starts to secrete unconjugated
Gilberts syndrom
What is prophyria?
group of disorders resulting from deficiencies in enzymes in the pathway for heme biosynthesis
What is the classical presentation of acute porphyria?
Abdominal pain + neuro disturbances
- must have very high suspicion to Dx it
What is porphyria cutanea tarda?
Deficiency in hepatic Uroporphyrinogin Decarboxylase
- cant make Coproporphyinogen III from Uroporphyrinogen III
- More commonly acquired by rare homozygous inheritance
- Risk factors: Increased iron stores, Hep C, estrogens, HFE hemochromatosis, African iron overload
What are the symptoms for Porphyria Cutanea Tarda?
Bullous dermatosis- blistering skin lesions
- Scarring
- Hyperpigmentation
- Hypertrichosis- abnormal Excessive hair
How do you Dx a person who you think has Porphyria Cutanea Tarda?
Lesions
- elevated Urine prophyrins with uroporphyrin..coproporphy
What is the treatment for Porphyria Cutaea Tarda?
Avoid alcohol
Phlebotomy 500ml/week
Iron chelation
What are the 2 forms of dietary iron?
- Heme iron- best absorbed from hemoglobin and myoglobin of chicken beef and fish
- Non-heme iron- cereal and vegetables. Taken up less avidly and vegetarians needs to be careful since must be converted from Fe3 to Fe2+
what are the common lab findings for a person with iron deficient anemia?
low serum iron
Low serum ferritin- less than 10
Low transferrin iron saturation
Increase in total iron binding capacity
Transferrin production is increased but low transferrin iron saturation45 year old man who is iron deficient, low iron and ferritin, increased total iron binding capacity. What is the next test?
Colonoscopy searching for a GI bleed
what are some chronic non-hematolitic conditions associated with Anemia of Chronic Disease?
Infectious like TB, endocarditis and AIDs
Malignant like Hodkin’s, NHL, Metastatic Dz
Immunologic like RA, SLE and vasculitis
Ischemic heart disease
Traumatic
how does one dx anemia of a chronic disease?
Low serum iron
Increase or normal serum ferritin (iron in cell)
Low transferrin
