title: Podocin and beta dystroglycan expression to study podocyte-podocyte and basement membrane matrix connections in adult protienuric states.
abstract: BACKGROUND
  Podocytes can be the primary site of injury or secondarily involved in various protienuric states. Cross talk between adjacent foot processes and with basement membrane is important for slit diaphragm function. Does expression of podocyte associated proteins in kidney biopsies alter with site/type of primary injury? Genetic mutations of podocin result in steroid resistant FSGS. Can protein expression of podocin predict resistant cases to initiate further genetic evaluation?
  
  
  METHODS
  Adult patients (n-88) with protienuria- minimal change disease(MCD)-22, focal segmental glomerulosclerosis(FSGS)-21,membranous glomerulonephritis(MGN)-25 and IgA nephropathy(IgAN)-20 were selected for immunohistochemistry with podocin and beta dystroglycan . Results were graded (0 - 3+scale )and compared with control biopsies and internal control. Treatment and follow up (6 months -2 ½ years) of FSGS and MCD cases were collected.
  
  
  RESULTS
  There was intense to moderate staining of the podocytes with podocin and β dystroglycan in the glomeruli in all cases (MCD, FSGS, IgAN and MGN) except for weak staining with β dystroglycan in 3 cases of MCD. There was loss of immunostains in areas of segmental/global sclerosis. There was no significant difference in the staining pattern between the groups. In primary podocytopathies, staining pattern did not differ between steroid resistant, sensitive or dependent cases.
  
  
  CONCLUSIONS
  Immunohistochemical expression of podocin and β dystroglycan does not differ in nephropathies which have different site of injury depending on absence (MCD and FSGS) or presence of immune deposits and their localization (MGN and IgAN). Podocin and β dystroglycan staining did not differentiate steroid sensitive and resistant cases, hence, does not give clue to initiate genetic studies. However, analysis of bigger cohort may be required.
  
  
  CONCLUSIONS
  Podocin and β dystroglycan immunohistochemistry was done to analyze podocyte - podocyte and podocyte -basement membrane matrix connections in adult protienuric states. Primary podocytopathies i.e. MCD and FSGS and secondary podocytopathy due to immune complex deposition, i.e., MGN (subepithelial) and IgAN (mesangial) were analyzed. There was no difference in staining patterns between primary and secondary podocytopathies or between steroid sensitive, resistant and dependent cases of FSGS and MCD.
  The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2258608781052786.
authors.forename: Praveen B
authors.initials: PB
authors.lastname: Shankar
authors.affiliation: Department of Histopathology, Post Graduate Institute of Medical Education and Research, Chandigarh 160012, India. ritamduseja@yahoo.com.
authors.forename: Ritambhra
authors.initials: R
authors.lastname: Nada
authors.forename: Kusum
authors.initials: K
authors.lastname: Joshi
authors.forename: Ashwani
authors.initials: A
authors.lastname: Kumar
authors.forename: Charan Singh
authors.initials: CS
authors.lastname: Rayat
authors.forename: Vinay
authors.initials: V
authors.lastname: Sakhuja
mesh_terms: D001485:Basement Membrane / Q000378:metabolism / Q000473:pathology*; D049030:Dystroglycans / Q000032:analysis / Q000096:biosynthesis*; D006801:Humans; D007150:Immunohistochemistry; D047908:Intracellular Signaling Peptides and Proteins / Q000032:analysis / Q000096:biosynthesis*; D007674:Kidney Diseases / Q000378:metabolism / Q000473:pathology*; D008565:Membrane Proteins / Q000032:analysis / Q000096:biosynthesis*; D050199:Podocytes / Q000378:metabolism / Q000473:pathology*; D011507:Proteinuria / Q000378:metabolism / Q000473:pathology*; D012189:Retrospective Studies
chemical_list: C483081:DAG1 protein, human; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C407223:NPHS2 protein; D049030:Dystroglycans