Hereditary spherocytosis.

Functionally normal cells which are destroyed .in spleen because of the structural abnormality. It is transmitted as an autosomal dominant trait 

Congenital hemolytic anemia due to genetically determined abnormal spectrin and ankyrin molecules, leading to defects in red blood cell membrane, causing spherical shape and lack of plasticity
Red blood cells become trapped within spleen and have less than usual 120 day lifespan
Splenic function is normal
Osmotic fragility: increased; basis for diagnostic testing 

Description

Firm, deep red tissue, thin capsule, no grossly identifiable malpighian follicles, 100-1000g
Peripheral blood images
Marked congestion in cords
Sinuses appear empty but actually contain ghost red blood cells
May have prominent endothelial lined sinuses, hemosiderin deposition, erythrophagocytosis

Graves disease 

Graves disease is an organ-specific autoimmune disorder that results in thyrotoxicosis due to overstimulation of the thyroid gland by autoantibodies. 
- It is the most common form of thyrotoxicosis, females being affected more than males by 8: 1. 
- It is usually associated with a diffuse enlargement of the thyroid.

Pathogenesis
 
IgG-type immunoglobulins bind to TSH membrane receptors and cause prolonged stimulation of the thyroid, lasting for as long as 12 hours 
(cf. 1 hour for TSH). The autoantibody binds at a site different to the hormone-binding locus and is termed the TSH-receptor autoantibody (TRAb); 95% of Graves’ disease patients are positive for TRAbs

Gross features 
- The thyroid gland is diffusely and moderately enlarged
- It is usually smooth, soft, and congested  

Histologically
- the gland shows diffuse hypertrophy and hyperplasia of acinar epithelium, reduction of stored colloid and local accumulations of lymphocytes with lymphoid follicle formation.

Clinical features

- Exophthalmos (protrusion of the eyeballs in their sockets)—due to the infiltration of orbital tissues by fat, mucopolysaccharides and lymphocytes. May cause compression of the optic nerve, hence blindness. However, only about 5% of Graves’ patients show signs of exophthalmos.
- Thyroid acropachy—enlargement of fingernails. 
- Pretibial myxoedema—accumulation of mucoproteins in the deep dermis of the skin.

Treatment is as for thyrotoxicosis.

Acute pericarditis

1. Characterized by inflammation of the pericardium.
2. Causes include:
a. Viral infection.
b. Bacterial infection, including Staphylococcus, Pneumococcus.
c. Tuberculosis.
d. MI.
e. Systemic lupus erythematosus.
f. Rheumatic fever.

3. Signs and symptoms include:
a. Pericardial friction rub on cardiac auscultation.
b. Angina.
c. Fever.

4. Consequences include constrictive pericarditis,which results from fusion and scarring of the pericardium. This may lead to the restriction of ventricular expansion, preventing the heart chambers from filling normally.

ANAEMIA
Definition. Reduction of the hemoglobin level below the normal for the age and sex of the patient

Classification
1. Blood loss anaemia:
- Acute.
- Chronic (results in iron deficiency).

2. Deficiency anaemia:

- Iron deficiency.
- Megaloblastic anaemia-BI2 and Folic acid deficiency.
- Protein deficiency.
- Scurvy-Vitamin C deficiency.

3. Marrow dysfunction:
- Aplastic anaemia.
- Marrow infiltration.
- Liver failure.
- Renal failure.
- Collagen diseases.

4 Increased destruction (Heamolysis)
- Due to corpuscular defects.
- Due to extra corpuscular defects
 

Acute tubular necrosis

Characterized by impaired kidney functions due to the destruction of the renal tubule epithelium.

Caused by a variety of conditions that lead to ischemia of the renal tubules, usually resulting from renal tubular injury or problems with vascular flow. It can also be induced by ingesting toxins or drug-related toxicity (e.g., gentamicin). 
The most common cause of acute renal failure.
Is a reversible condition, although it can be fatal.

Joint pathology
1. Rheumatoid arthritis
a. Cause is autoimmune in nature.
b. More common in women aged 20 to 50.
c. Characterized by inflammation of the synovial membrane. Granulation tissue, known as pannus, will form in the synovium and expand over the articular cartilage. This causes the destruction of the underlying cartilage and results in fibrotic changes and ankylosis.
Scarring, contracture, and deformity of the joints may occur.
d. Clinical symptoms include swollen joints. It can affect any joint in the body.

2. Osteoarthritis
a. Most common arthritis.
b. Cause is unknown.
c. Higher incidence in women, usually after age 50.
d. Characterized by degeneration of the articular cartilage and the formation of osteophytes (bony spurs) at the margins of affected areas.
Clinical signs and symptoms include:
(1) Stiff and painful joints affecting joints in the hand (phalangeal joints) and weight-bearing joints.
(2) Heberden’s nodes—nodules at the distal interphalangeal joint.
(3) Bocard’s nodes—nodules at the proximal interphalangeal joint.