In the NEWS:-Pregnancy and the Kidney

http://onlinedigeditions.com/publication/?m=15191&l=1
ASN Kidney News July 2011 has an entire issue on Pregnancy and Kidney Disease from basics to transplant related issues.

TOPIC DISCUSSION: Methotrexate in the urine

Methotrexate can cause renal damage is well known but precipitation in the urine and appearance in urine analysis is unique.  Tubular obstruction damage and urine precipitation noted in a recent picture in Kidney International highlights this toxicity.  Check it out below

Ref:
http://www.nature.com/ki/journal/v80/n2/abs/ki201197a.html

TOPIC DISCUSSION: Dendritic Cells and Renal disease

Dendritic cells(DC) are traditional thought to be anti infectious and a link between the innate and the adaptive immune system.  A nice breakdown of DC role in kidney disease recently discusses its role in homeostatic, anti inflammatory and pro inflammatory roles in kidney diseases.
In terms of homeostatic roles: there is evidence that DCs can do some immune tolerance in renal allografts, and small molecular weight antigens.  The anti inflammatory roles have been in mostly nephrotoxic nephritis(drug induced) especially cisplatin nephrotoxicity. Some data is also present in suppressing pro inflammatory cytokines in ischemic reperfusion injury. Most of the data is in being pro inflammatory in nature and that is in causing proteinuria, promoting ANCA through Th cells, IL-12 secretion in lupus and Th1 response in tubular insterstitial disease.
This leads us to believe that there might be many types of DC and there are.  CD11B like DC due immune surveillance and activate Th cells and are present in kidney in certain glomerular diseases.  CD8 like DC are found in renal lymph nodes and have some T cell activation role.  Inflammatory DC regulate Th cells and Plasmacytoid DC may have some role in lupus nephritis.

Check out these recent references.

Ref:
http://www.ncbi.nlm.nih.gov/pubmed/21613986
http://www.ncbi.nlm.nih.gov/pubmed/19276627
http://www.ncbi.nlm.nih.gov/pubmed/19381017

Many guidelines equal no guildelines for cardiac evaluation before renal tranplantation

The degree of cardiac testing for potential transplant recipients is highly variable and depends on the practices of the particular transplant center. Multiple guidelines have been proposed by experts in the field however there is a huge variability between each guideline. At the two ends of the spectrum are the KDOQI guidelines which suggest universal testing for CAD at regular intervals depending on risk, and the ACC/ AHA who recommend testing only for symptomatic patients or patients who can not achieve 4 mets of activity. A recent article in cJASN by Friedman et al. demonstrates this beautifully(1). The authors had performed cardiac testing in 87% of their patients then retrospectively applied the KDOQI, AST, Lisbon and ACC/AHA criteria to thier patients to assess how many would have been tested. Turns out that 100%, 92%, 68% and 20% would have been screened respectively. The authors discovered ischemic disease in 17 (10%) of their patients and 10 of them underwent revascularization (7 had single vessel PCI). KDOQI and AST guidelines would have picked up all of the cases, Lisbon criteria would have picked up 16 patients and ACC/AHA would have picked up 4 of the patients with ischemia. The problem is that it is not clear whether identifying ischemia or performing revascularization in such patients is of any benefit in reducing cardiovascular event rates! In fact there are well designed studies that show pre-surgical revascularization in all patients with ischemic heart disease does not reduce cardiovascular morbidity and mortality in patients undergoing major vascular surgery(2) - but of course these studies were not in dialysis patients...

What we need is a large multicenter randomized controlled trial to evaluate the potential benefit in pre-transplant cardiac testing +/- revascularization in reducing cardiac morbidity and mortality in patients undergoing renal transplantation - to settle the question once and for all.

Reference:
1. Friedman et al. A Call to Action: Variability in Guidelines for Cardiac Evaluation before Renal Transplantation. cJASN 2011;6:1185
2. McFalls et al. Coronary-artery revascularization before elective major vascular surgery. N Engl J Med 2004;351: 2795
2804, 2004

Topic Discussion: Warfarin Related Nephropathy

A commonly used agent is warfarin for anticoagulation.  Recently there have been some published case reports of warfarin induced nephropathy(WRN). More recent, an original article on the incidence and prevalence of this entity in CKD has also been mentioned.

What is this entity? High INR was associated with a rise in crt in biopsy of patients showed glomerular hemorrahge and renal tubular obstruction with red blood cell casts.  A recent retrospective review of over 15000 patients who were on warfarin and had an INR >3 and creatinine at the same time were reviewed.  A presumptive diagnosis of warfarin induced toxicity in the kidney was made if crt increased by 0.3mg/dl in 1 week after INR was >3.  WRN occurred in 20.5%,and 33% of the patients with CKD.  The mortality was also higher with people with this entity.  Other diagnosis that could have cause an acute renal injury were considered in those 4006 patients and carefully ruled out by looking at the chart.

The study highlighted few important points:
1. This entity should be considered in the differential diagnosis with AKI on warfarin
2. The risk factors to make this risk higher were age, DM, HTN and CVD but most important risk factor that doubled the risk was CKD.
3. Average INR to show this entity was only 4
4. The higher risk of WRN in CKD patients maybe be more likely due to having a sub therapeutic INR
5. There is no correlation of WRN and level of INR
6. WRN has substantial decreased survival rate but unclear if this is purely from WRN or other co morbid conditions.
7. Glomerular hemorrhage leading to tubular cast obstruction leading to ATN is the most likely mechanism
RFN also blogged about this in 2010 at
http://renalfellow.blogspot.com/2010/08/warfarin-induced-aki.html
Read more at the following references:
http://www.ncbi.nlm.nih.gov/pubmed/21389969
http://www.ncbi.nlm.nih.gov/pubmed/20413993
http://www.ncbi.nlm.nih.gov/pubmed/19577348

TOPIC DISCUSSION: Wunderlich Syndrome

Wunderlich syndrome can be seen in dialysis patients.  It is spontaneous non traumatic renal hemorrhage.  Usually this is seen in angiomyolipomas and sometimes even in urothelial cell cancers. Some cancers are common in dialysis patients, renal cell or urothelial can be seen.  Usually the syndrome presents with back pain, flank pain or hip pain.  CT scan can diagnosis it. If they are not making urine, blood in the urine might not be noted.  A high index of suspicion in at-risk patients therefore is important to timely identify and manage this disease.

A recent AJKD article describes this entity.

Ref:

http://www.ncbi.nlm.nih.gov/pubmed/21684433

http://www.ncbi.nlm.nih.gov/pubmed/21566314

ASN Podcast on Nephrology Blogging Part 1

Check out the Nephrology Blogging world get interviewed by ASN Kidney News: It features Blogging world of Nephrology via discussions with Renal Fellow Network and Nephronpower editors.

http://www.asn-online.org/publications/kidneynews/podcast.aspx