Question

Clinical application

Claire Diego is an 11 year old girl living in Los Angeles. She complains of having to urinate more frequently with a large urine volume. She also is very thirsty. She has no previous illnesses, except that 6 weeks ago she developed a sore throat. It persisted for 2.5 weeks until she was seen by her pediatrician. At that time it cleared over the next 2 weeks with antibiotics. She is current on her vaccinations. She has had no travel out of the State of California in her life. The family has no pets or contact with wildlife.

Her physical exam is unremarkable.

Her blood pressure is 120/77.

Other lab values:

Blood sugar = 99

ADH level = normal

Aldosterone level = normal

Urinalysis:

albumin = 5+

RBC’s = 40-50/HPF

Urine culture = negative

***If I said this was a renal corpuscle problem, what link can you see to the sore throat in her history?

Hint: how could antigen/antibody complexes and complement, then inflammation, from the immune system be involved in the etiology of the abnormality?

Look again at filtration pressures in the renal corpuscle. Which one of the pressures would now be abnormal in this patient? _____________.

Assign that pressure 14 mmHg.

Now draw a picture of the forces effecting filtrate flow through this patient’s renal corpuscle and show why she is she urinating more. Show her NFP.

Answer 1

Answer 1) From the clinical information available Clarie Diego is suffering from Poststreptococcal Glomerulonephritis(PSGN) .PSGN is common in 2 to 14 years of age . Th e onset of disease is generally sudden after 1-2 weeks of streptococcal infection, most frequently of the throat (e.g. streptococcal pharyngitis) and sometimes of the skin (e.g. streptococcal impetigo).So from Sore throat it is related to PSGN.

Answer 2)Particularly nephritogenic are types 12,4,1 and Red Lake of group A -haemolytic streptococci.Antibodies are formed against this and Th e glomerular lesions appear to result from deposition of immune complexes in the glomeruli. Persistence of low-grade microbial infection

A low grade infection with bacteria Group A Streptococcus stimulates a somewhat weak antibody response. Persistence of infection (antigen) and corresponding weak antibody response leads to chronic antigen-antibody complex formation. Since these complexes fail to get eliminated from body fluids, they are instead deposited in tissues e.g.glomeruli .which is followed by activation of the complement system and infl ammatory reaction, resulting in cell injury.

Answer 3)As the albumin is present in urine it shows the Albumin is not reabsorbed in blood so the Colloid osmotic pressure of the Glomerulus decreases .So value of 14 mm hg is the Osmotic pressure in Glomerulus .Normal is 32 mm hg

The NFP( Net filtration pressure ) is the algebraic sum of the hydrostatic pressures and the osmotic pressures resulting from pro-tein-the oncotic, or colloid osmotic pressures-on the two sides of the capillary wall. There are four pressures to consider: two hydrostatic pressures and two oncotic pressures.

These are the Starling forces.

NFP = [(PGC – PBS) + (πBS – πGC)]

= [(60 – 18) + (0 – 14)] mm Hg

= 28 mm Hg

GC = Glomerular capillary, BS = Bowman’s space, P = Hydrostatic pressure, π = Oncotic pressure.

Hydrostatic pressure always try to push the fluids out of the compartment either Glomerular capillary or Bowman space .

Oncotic pressure always try to retain the fluids in the compartment ( Either Glomerular or Bowmans space ).

Normally there is retention of urine in PSGN as the Glomerulus is inflammed but as she is passing more urine and ADH and Aldosterone levels are normal.As she is passing more urine and also thirsty she may be suffering from Diabetes Mellitus ( juvenile ) .Otherwise passage of urine is less in PSGN .Also there is retention of urine and swelling of hands ,feet ,raised blood pressure in PSGN .