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250 Chapter 6: Genitourinary system

Management Pathophysiology
Any underlying cause should be treated. Where no cause The GBM is more permeable to proteins but the cause
hasbeenidentified,treatmentisdisputed,asthecourseis of this is unclear.
often slow and spontaneous remission may occur. There Podocyte damage: The initial problem may be dam-
is evidence that intensive immunosuppression with cor- age to the epithelial cells (podocytes), attached to the
ticosteroids and chlorambucil or cyclophosphamide for GBM, possibly due to a circulating factor.
6months improves prognosis, but this has a significant Glomerulosclerosis: Denudement of the basement
risk of adverse effects. Other treatments include ACE membrane may lead to adhesion to the Bowman’s
inhibitors, NSAIDs and omega-3 fatty acids (fish oils). capsule. Alternatively large plasma proteins may
leak through the capillary wall, accumulate in the
subendothelial space and compress the capillary
Prognosis
lumen.
Approximately 50% develop CRF over 10 years; 25%
Over time, the sclerosis affects more segments of the
undergo remission; 25% have stable, persistent protein-
glomerulus, leading to global sclerosis and permanent
uria. Some patients develop a rapidly progressive course
loss of the function of that nephron.
to end-stage renal failure.
Clinical features
Focal (segmental) glomerulosclerosis In children and young adults with rapid onset of
nephrotic syndrome, FSGS is suggested by atypical fea-
Definition tures such as non-selective proteinuria, haematuria, hy-
Focal segmental glomerulosclerosis (FSGS) is one of the pertension or renal impairment at the onset of nephrotic
two most common primary causes of nephrotic syn- syndrome. These may develop later in the course of
drome in adults and the second most common cause the illness. Steroid non-responsiveness in a patient
in children. with apparent minimal change disease also suggests
FSGS.
Incidence/prevalence
Causes ∼20% of cases of nephrotic syndrome in adults Macroscopy/microscopy
and children. Increase in the mesangial matrix in glomeruli in a focal
segmental pattern, with collapse of the adjacent capillary
loop.Theremaybetubularatrophyandinterstitialfibro-
Aetiology sis.Immunofluorescenceusuallyshowsalackofimmune
There are several classifications of FSGS, for example by deposits, apart from some non-specific binding of gran-
the likely cause: ular IgM and C 3 in the sclerosed areas of mesangium.
Primary FSGS: This is the idiopathic form, which

tends to present with overt nephrotic syndrome in
Investigations
children and young adults.
Definitive diagnosis can only be made on renal biopsy.
Secondary FSGS: This tends to present with protein-

Because of the focal nature of the disease and the ten-
uria and renal insufficiency, without nephrotic syn-
dency for the juxta-medullary glomeruli to be affected
drome, usually in older adults. It is thought to be part
first, the disease may be missed on renal biopsy (and
of a physiological response to glomerular hyperfiltra-
hence a diagnosis of minimal change disease made).
tion/hypertrophy (e.g. in unilateral renal agenesis, re-
flux nephropathy, diabetes, pre-eclampsia) or previ-
ous focal damage to the glomerulus and then heal- Management
ing by scarring such as following vasculitis or lupus Almost all patients are treated with ACE inhibitors and
nephritis. cholesterol-loweringagents.ACE-inhibitorslowerintra-
Specific causes such as drugs, toxins, HIV, heroin and glomerular pressure and so reduce proteinuria (with a

familial forms. probable slowing of deterioration of renal function).