Nephritic syndrome

Characterized by inflammatory rupture of the glomerular capillaries, leaking blood into the urinary space.

Classic presentation: poststreptococcal glomerulonephritis. It occurs after a group A, β–hemolytic Streptococcus infection (e.g., strep throat.)

Caused by autoantibodies forming immune complexes in the glomerulus.

Clinical manifestations: 

oliguria, hematuria, hypertension, edema, and azotemia (increased concentrations of serum urea nitrogen
and creatine).

Lupus erythematosus
 - chronic discoid lupus is primarily limited to the skin, while SLE can involve the skin and other systems.
 - pathogenesis: light and other external agents plus deposition of DNA (planted antigen) and immune complexes in the basement membrane.
 Histology:
 - basal cells along the dermal-epidermal junction and hair shafts (reason for alopecia) are vacuolated (liquefactive degeneration)
 - thickening of lamina densa as a reaction to injury.
 - immunofluorescent studies reveal a band of immunofluorescence (band test) in involved skin of chronic discoid lupus or involved/uninvolved skin of SLE.
 - lymphocytic infiltrate at the dermal-epidermal junction and papillary dermis.  

HAEMORRHAGIC DISORDERS

Normal homeostasis depends on

 -Capillary integrity and tissue support.

- Platelets; number and function

(a) For integrity of capillary endothelium and platelet plug by adhesion and aggregation

(b) Vasoactive substances for vasoconstriction

(c) Platelet factor for coagulation.

(d) clot retraction.

- Fibrinolytic system(mainly Plasmin) : which keeps the coagulation system in check.

Coagulation disorders

These may be factors :

Deficiency .of factors

• Genetic.
• Vitamin K deficiency.
• Liver disease.
• Secondary to disseminated intravascular coagulation.or defibrinatian

Overactive fibrinolytic system.

Inhibitors of  the factors (immune, acquired).

Anticoagulant therapy as in myocardial infarction.

Haemophilia. Genetic disease transmitted as X linked recessive trait. Common in Europe. Defect in fcatorVII   Haemophilia A .or in fact .or IX-Haemaphilia B (rarer).

Features:

• May manifest in infancy or later.
• Severity depends  on degree of deficiency.
• Persistant wound bleeding.
• Easy Bruising with Hematoma formation

Nose bleed , arthrosis, abdominal pain with fever and leukocytosis

Prognosis is good with prevention of trauma and-transfusion of Fresh blood or fTesh plasma except for danger of developing immune inhibitors.

Von Willebrand's disease. Capillary fragility and decreased factor VIII (due to deficient stimulatory factor). It is transmitted in an autosomal dominant manner both. Sexes affected equally

Vitamin K  Deficiency. Vitamin K is needed for synthesis of factor II,VII,IX and X.

Deficiency maybe due to:

Obstructive jaundice.

Steatorrhoea.

Gut sterilisation by antibiotics.

Liver disease results in :

Deficient synthesis of factor I II, V, Vll, IX and X  Incseased fibrinolysis (as liver is the site of detoxification of activators ).

Defibrination syndrome. occurs when factors are depleted due to disseminated .intravascular coagulation (DIC). It is initiated by endothelial damage or tissue factor entering the circulation.

Causes

Obstetric accidents, especially amniotic fluid embolism. Septicaemia. .

Hypersensitivity reactions.

Disseminated malignancy.

Snake bite.

Vascular defects : (Non thrombocytopenic purpura).

Acquired :

Simple purpura a seen in women. It is probably endocrinal

Senile parpura in old people due to reduced tissue support to vessels

Allergic or toxic damage to endothelium due to  Infections like Typhoid Septicemia

Col!agen diseases.

Scurvy

Uraemia damage to  endothelium (platelet defects).

Drugs like aspirin. tranquillisers, Streptomvcin pencillin etc.

Henoc schonlien purpura Widespeard vasculitis due to hypersensitivity to bacteria or foodstuff

It manifests as :

Pulrpurric rashes.

Arthralgia.

Abdominal pain.

Nephritis and haematuria.

Hereditary :

(a) Haemhoragic telangieclasia. Spider like tortous vessels which bleed easily. There are disseminated lesions in skin, mucosa and viscera.

(b) Hereditary capillary fragilily similar to the vascular component of von Willbrand’s disease

.(c) Ehler Danlos Syndrome which is a connective tissue defect with skin, vascular and joint manifestations.

Platelet defects

These may be :

(I) Qualitative thromboasthenia and thrombocytopathy.

(2) Thrombocytopenia :Reduction in number.

(a) Primary or idiopathic thrombocytopenic purpura.

(b) Secondary to :

(i) Drugs especially sedormid

(ii) Leukaemias

(iii) Aplastic-anaemia.

Idiopathic thrombocytopenic purpura (ITP). Commoner in young females.

Manifests as :

Acute self limiting type.

Chronic recurring type.

Features:

(i) Spontaneous bleeding and easy bruisability

(ii)Skin (petechiae), mucus membrane (epistaxis) lesions and sometimes visceral lesions involving any organ.

Thrombocytopenia with abnormal forms of platelets.

Marrow shows increased megakaryocytes with immature forms, vacuolation, and lack of platelet budding.

Pathogenesis:

hypersensitivity to infective agent in acute type.

Plasma thrombocytopenic factor ( Antibody in nature) in chronic type

EMBOLISM

Definition: transportation of an abnormal mass of an abnormal mass of undissolved material from one part of circulation to another. The mass transported is called embolus.

Types
I .Thrombi and clots.
2. Gas or air.
3. Fat
4.Amniotic fluid.
5.Tumour

Thromboembolism 
This is the commonest type of embolus and may be formed of the primary thrombus  or more often of propagated clot region which is loosely attached.

Emboli from venous thrombi can result In impaction in the pulmonary  arteries and result in sudden death.
Embolism from cardiac or arterial thrombi results in systemic embolism causing infraction and gangrene.

Gaseous
This occurs when gas is introduced into the circulation:
•    Accidental opening of large veins during surgery.
•    Mismanaged transfusion. .
As air is  readily absorbed into blood only  sudden introduction or large quantities of air produces effects
Caisson’s Disease  bubbling of nitrogen from the blood during sudden decompression as seen during deep sea diving.

Fat Embolism
Causes
•    Fractures especially of long bones and multiple
•    Crush injuries.

Sites of impaction:

o    Lungs.
o    Systemic: causing -
    →    petechial skin haemorrhages.
    →    Embolism to brain leading to coma and death.
    →     Conjunctival and retinal haemorrhages
    
Tumor Embolism.

Invasion of vascular channe1.s is a feature of malignant neoplasms and this leads to:
•    Metastatic deposits,
•    DlC
 

Verruca vulgaris
1. Commonly known as warts.
2. Caused by the human papillomavirus (HPV).
3. Warts can be seen on skin or as an oral lesion (vermilion border, oral mucosa, or tongue).
4. Transmitted by contact or autoinoculation.
5. A benign lesion.

TOXOPLASMOSIS

Infection with Toxoplasma gondii, causing a spectrum of manifestations ranging from asymptomatic benign lymphadenopathy to life-threatening CNS disease, chorioretinitis, and mental retardation.

Symptomatic infections may present in several ways

Acute toxoplasmosis may mimic infectious mononucleosis with lymphadenopathy, fever, malaise, myalgia, hepatosplenomegaly, and pharyngitis. Atypical lymphocytosis, mild anemia, leukopenia, and slightly abnormal liver function tests are common. The syndrome may persist for weeks or months but is almost always self-limited.

A severe disseminated form characterized by pneumonitis, myocarditis, meningoencephalitis, polymyositis, diffuse maculopapular rash, high fevers, chills, and prostration. Acute fulminating disease is uncommon.

Congenital toxoplasmosis usually results from a primary (and often asymptomatic) acute infection acquired by the mother during pregnancy. The risk of transplacental infection increases from 15% to 30 to 60% for maternal infections acquired in the 1st, 2nd, or 3rd trimester of gestation, respectively