17_HST110 Introduction to the Histology of the Kidney-The Basic Techniques

Question 1

What stains are used in light microscopy analysis of morphological feature of the kidney?

Answer 1

H&E, PAS, silver methenamine (Jones), trichrome, (Congo red; von Kossa, alizarin red)

Question 2

Under immunohistochemistry, what proteins are tagged in immunofluorescence?

Answer 2

IgG, IgA, IgM, kappa, lambda, C3, C1q, C4d, albumin, fibrin, (protein A, transthyretin, collagen)

Question 3

Under immunohistochemistry morphological techniques, what does IMPOX look for?

Answer 3

viruses (BK, CMV, adenovirus), lymphocyte and other cell markers, lysozyme, hemoglobin, myoglobin, etc.

Question 4

What does one look for using electron microscopy of renal tissues?

Answer 4

podocyte integrity, lysosomal inclusions, location of EDD, substructure in EDD, fibrillary material and measurements, texture and thickness of the BM, viral particles, mitochondrial changes, etc.

Question 5

What fixative is used for light microscopy preservation and preparation before paraffin embedding?

Answer 5

Formaldehyde solution

Question 6

What solution is used to prevent protease-dependent protein disturbance for immunofluorescence microscopy?

Answer 6

Michel’s solution

Question 7

What fixative solution is used for electron microscopy preservation and preparation?

Answer 7

Paraformaldehyde/glutaraldehyde solution (Karnovsky’s Fixative)

Question 8

PAS (periodic acid Schiff) is a histochemical technique detecting sugar moieties to highlight (X). PAS stains glycosylated proteins (Y)

Answer 8

X = basement membrane
Y = purple

Question 9

What cellular features need to be considered in glomerular pathology by LM?

Answer 9

Type of cells (mononuclear, PMN, Eos etc.)
Location of cells (tuft vs. Bowman’s space
Capillaries vs. mesangial space)
Intensity and frequency

Question 10

What spaces need to be considered in glomerular pathology by LM?

Answer 10

Capillary lumen (open, occluded, collapsed) Bowman’s space (open, distended, cells)

Question 11

What matrix features need to be considered in glomerular pathology by LM?

Answer 11

Basement membrane (thickness, “spikes” and “craters”, duplicated (double contours)

Mesangial matrix (nodules, PAS-positivity, Congo red); scar collagen

Question 12

What is the definition of a focal issue?

Answer 12

A subset of elements is involved (<50%)

Question 13

What is the definition of a diffuse issue?

Answer 13

All elements are involved (>50%)

Question 14

What is the definition of a global issue?

Answer 14

The entire element (e.g glomerulus) is involved

Question 15

What is the definition of a segmental issue?

Answer 15

A segment or sector of the element (e.g. glomerulus) is involved

Question 16

What does endocapillary mean?

Answer 16

Affecting the tuft

Question 17

What does extracapillary mean?

Answer 17

Affecting the Bowman’s space

Question 18

What does proliferative mean?

Answer 18

Increase in number of cells, exudative (inflammatory)

Question 19

What does membranous mean in the context of renal pathophysiology?

Answer 19

Thickened capillary walls (“spikes”)

Question 20

What does membranoproliferative mean in the context of renal pathophysiology?

Answer 20

Thickened capillary wall (double contours) and increase in the number of cells

Question 21

The hematoxylin and eosin stains nuclei in (X) and the cytoplasm and various proteins in (Y)

Answer 21

X = blue
Y = red-pink-orange

Question 22

Hemoglobin is not strongly stained by (X) (RBCs not strongly glycosylated)

Answer 22

X = PAS

Question 23

Lysosomal accumulation of proteins (as in (X) disease) can lead to massive vacuolization of the (Y) since they are never regenerated (other cells affected, but can be renewed before extensive vacuoles accumulate)

Answer 23

X = Fabry
Y = podocytes

Question 24

Glomerulitis is (X) of the glomerulus, either segmental or global

Answer 24

X = inflammation

Question 25

A global glomerulitis is mostly due to infilration of (X) inflammatory cells exhibiting a lobular pattern of injury

Answer 25

X = mononuclear

Question 26

A cellular crescent, focal fibrinoid necrosis, and shrunken glomerulus can result in the case of inflammation due to the accumulation of (X) and parietal epithelial cells in Bowman's space

Answer 26

X = macrophages/monocytes

Question 27

Nodular accumulation of PAS-positive matrix in the mesangium is a classic presentation in (X)

Answer 27

X = DM (Diabetes Mellitus)

Question 28

Amyloid deposits stain weekly with PAS and exhibit a characteristic (X) when stained with Congo red and viewed under polarized light

Answer 28

X = apple green birefringence

Question 29

(X) are commonly seen in Membranoproliferative glomerulonephritis, where a second basement membrane is deposited after injury

Answer 29

X = Double contours

Question 30

What type of collagen is considered the scar collagen seen in the healing of a focal necrotizing lesion?

Answer 30

Collagen I (Lightly staining in PAS)

Question 31

For IF microscopy section preparation, the tissue is not fixed. Instead, it is (X)

Answer 31

X = snap frozen

Question 32

What are the major elements to consider in glomerular pathology by IFM?

Answer 32

``` The antibodies used are chain-specific The distribution of the deposits Type of deposits Location of the deposits Intensity of staining (0 to 3+ or 4+) ```

Question 33

What chain -specific antibodies are considered in IFM?

Answer 33

anti-IgG=anti-g heavy chain; etc.

Question 34

What are potential locations of deposits seen in IFM?

Answer 34

peripheral capillary wall, mesangium, capillary lumen, Bowman space, tubular basement membranes, vascular wall, nuclear staining

Question 35

What cells produce the kappa or lambda light chains which have affinity for the glomerulus?

Answer 35

B cells and plasma cells

Question 36

Tissue is embedded in hard (X) to achive ultra-thin sections of the tissue on the ultramicrotome for EM

Answer 36

X = epoxy resin

Question 37

High protein content can be seen as (X) regions under EM. E.g. RBCs

Answer 37

electron dense

Question 38

(X) on the endothelium in the kidney is much higher than in other organs with lower perfusion/gram (such as the brain). Higher pressure also seen in this system. Thus, the kidney expresses thrombotic and cardiovascular diseases long before other organs become clinically involved

Answer 38

X = Shear stress

Question 39

What type of hemoglobin forms the fibrils seen in sickle cell anemia?

Answer 39

Hemoglobin S

Question 40

Lyme disease exhibits (X) in the glomerular basement membrane

Answer 40

X = double contours

Question 41

Immune complex accumulation on the luminal side of glomerular capillaries is a classic presentation of (X)

Answer 41

X = serum sickness

Question 42

Deposits in monoclonal IgG/kappa deposition disease appear almost (X)

Answer 42

X = crystalline

Question 43

AL (Lambda-derived) amyloidosis shows podocytes being pushed aside by (X) of fibrils, in appearance similar to crystal growth

Answer 43

X = spicules

Question 44

(X) can be used to analyze local protein content to discover and/or back-calculate abnormal quantities, types, or localizations

Answer 44

X = Laser microdissection + peptide extraction + tandem spectrometry