Cystic kidney diseases by nephrology resident Mariam Mustafa presented during KUC weekly meeting on 2nd Nov 2021

1. Cystic kidney
diseases
Mariam Mustafa

2. Classification of cystic renal diseases:
A) Non genetic cystic renal diseases:
Simple cysts
Complex cysts
Cystic neoplasms
Multi-cystic dysplasia
B) Genetic cystic renal diseases
Autosomal dominant polycystic kidney disease
Autosomal dominant tubulointerstitial kidney disease
Multi-organ syndromes with pluricystic kidneys: Tuberous sclerosis, Von Hipple
Lindau

3. Simple cysts

5. Complex cysts
The most important issue is the differential diagnosis from the malignant tumors

8. ● Benign multiloculated cystic nephroma (MLCN), cystic Wilms
tumor and cystic renal cell carcinoma (RCC) are the most
frequent neoplasms.
● MLCN is a rare and benign neoplasm with an excellent prognosis
with bimodal distribution of age, children within 2 years of age and
in adults over 30 years
● Cystic RCCs make up almost 5% percent of all RCCs and are usually
of clear cell type. They have a better prognosis than the solid RCCs
Cystic renal cell neoplasms

9. Medullary sponge kidney
Some patients with MSK are asymptomatic. In such patients, the disease either remains
undiagnosed or is discovered incidentally with a radiographic study performed for some
other indication.

10. Medullary sponge kidney
● MSK is a well known cause of nephrocalcinosis and calcium kidney
stones
● (MSK) has an excellent long-term prognosis .
● The plasma creatinine concentration remains normal in most
cases. However, stone-induced episodes of obstruction can lead
to transient reductions in the (GFR), and numerous episodes of
obstruction and/or recurrent infection can occasionally lead to
(ESKD)

13. Medullary Cystic Kidney Diseases (MCKD)
Medullary Cystic Kidney Diseases (MCKD)

15. Tubular
damage and
interstitial
fibrosis
CKD
and
ESRD
In abscence of
glomerular
lesion
01 02 03

16. Autosomal Dominant polycystic
Kidney Disease
(ADPKD)
16

18. • Autosomal dominant polycystic kidney disease (ADPKD) is a common disorder,
occurring in approximately 1 in 1000 live births
• ADPKD affects about 12.5 million individual worldwide
• The fourth most common cause of renal replacement therapy worldwide
• ADPKD is more common than sickle cell disease, Down syndrome, cystic fibrosis,
hemophilia and Huntington disease combined
ADPKD is an inherited, progressive, incurable, multisystem disorder leading to ESRD
in 50% of patients by the age of 60
Epidemiology

21. Pathophysiology and genetics

31. The dosage model of cystogenesis

35. Warburg effect

40. Imaging modalities

44. CRISP showed total
kidney volume (TKV)
increases exponentially
in autosomal dominant
polycystic kidney disease
(ADPKD).
CRISP also
showed that
TKV is
prognostic of
faster decline in
renal function.
The Consortium for Radiological Imaging Studies of
PKD (CRISP)
• ADPKD patients with steeper
increases in TKV can be
identified years before
progressive decline in GFR.
• Establishing a causal link
between TKV and renal
function is critical for future
applications of TKV as a
surrogate marker.

46. Mayo TKV classification

55. Tight BP control
The HALT PKD Study A trial compared intensive (95–110/60–75 mm Hg) and standard
(120–130/70–80 mm Hg) BP control in 15- to 49-year-old patients with eGFR>60
• Intensive treatment lowered the percent TKV increase by 14.2%
• After month 4, eGFR decline was marginally slower with intensive treatment
We recommend a rigorous BP target (<110/ 75 mm Hg) if tolerated in young hypertensive
adults with an eGFR>60, particularly those with severe kidney disease (class C–E by the imaging
classification) or cardiovascular associations such as intracranial aneurysms or valvular heart
disease.

58. Hydration
Two hydration trials are ongoing:
• PREVENT-ADPKD
• the Impact of Increased Water Intake in CKD trial
Until more information becomes available, our recommendation is for moderately
enhanced hydration spread out over 24 hours (during the day, at bedtime, and at night if
waking up) to maintain an average urine osmolality of #280 mOsm/L
A large body of evidence suggests that vasopressin is important not only in the development
of cystic disease in ADPKD but also in the progression of CKD in general

59. ● Dietary salt restriction
Dietary sodium was significantly associated with rates of TKV increase in
HALT PKD Study A and of eGFR decline
We recommend a daily sodium intake of 2.3 g
● Moderate phosphorus restriction
800mg/day
● excess phosphate contributes to CKD progression and limits the reno-
protective effect of ACE inhibition, possibly through stimulation of
fibroblast growth factor 23 (FGF23) secretion and FGF23-mediated
inhibition of nitric oxide production
● Moderate protein restriction
0.8-1g/kg ideal body weight
Dietary restrictions

60. Mild reduction in food intake was recently shown to slow polycystic kidney disease (PKD)
progression in mouse models, but whether the effect was due to solely reduced calories or
some other aspect of the diet has been unclear
we now show that the benefit is due to the induction of ketosis. Time-restricted feeding,
without caloric reduction, strongly inhibits mTOR signaling, proliferation, and fibrosis in the
affected kidneys in a PKD rat model
A ketogenic diet had a similar effect and led to regression of renal cystic burden. Acute fasting in
rat, mouse, and feline models of PKD results in rapid reduction of cyst volume, while oral
administration of the ketone β-hydroxybutyrate (BHB) in rats strongly inhibits PKD progression.
Individuals with ADPKD and type 2 diabetes have significantly larger total kidney volume
(TKV) than those with ADPKD alone and overweight or obesity associates with faster
progression in early-stage ADPKD

61. Pathophysiology/therapeutic targets

70. Thank you