Q.670. How could patient survival after renal transplantation be affected?
Solid-organ transplant (SOT) TR are immunocompromised and may be at higher risk for severe COVID-19 disease as compared to general population. Two large observational studies of SOT recipients with COVID-19, about 80-90 % of ptns required hospitalization; of those, nearly 40 % required intensive care & 30 % required mechanical ventilation. At one month, mortality (MR) exceeds > 20 %. These findings suggest: TR are at a higher risk for poor outcomes, multivariate analyses in both studies reported that age & chronic co-morbidities were the primary drivers of MR rather than immunosuppression.
Leeaphorn N, Thongprayoon C, Chon WJ, et al. Outcomes of kidney retransplantation after graft loss as a result of BK virus nephropathy in the era of newer immunosuppressant agents. Am J Transplant 2020; 20: 1334.
Kates OS, Haydel BM, Florman SS, et al. COVID-19 in solid organ transplant: A multi-center cohort study. Clin Infect Dis 2020.
I. General topics.
III. Drugs of transplantation.
IV. Rejection after transplantation.
V. Complications of transplantation.
VIII. Stem cell transplantation.
﴾﴾ I. General Topics. ﴿﴿
Q.670. How could patient survival
after renal transplantation be affected?
A. Kidney Tx. is ➳ ttt of choice for selected ptn é ESRD. It confers the highest survival benefit among all different RRT. Survival benefit hs bn obs. in: [diabetics, African-Americans, obese ptn.s & in ptn in all age groups, as well as in those who’re recip. of marginal kidneys] . Reasons are unclear. Despite survival benefit conferred by Tx. comp. to DX., R. recip. still have a high M.R. comp. é controls. Survival rates vary based é source of allograft, age & pres. & degree of severity of comorbid dis.. Other factors:[Gender, race & degree of im/m.].
C.V.S. dis. leading cause of death for adult R. allograft recip.. De novo H.F. is common after R.Tx. & associated é poor survival. Among ptn. requiring intervention for CAD after Tx.,“myocardial revascularization” is associated é acceptable immediate & long-term survival & similar outcomes in percutaneous & surgical techniques. Survival of diabetics after R.Tx. is lower thn tht for nondiabetics due to pres. of PVD.. However, survival é Tx. diabetics is still markedly better thn tht é DX. .
Infections🠞leading cause of mortality é early post Tx. period & are related to the level of overall im/m. rather thn the use of a sp. im/m. agent. Particular causes of death hs changed over time & varies é age. Single center study: % of deaths due to: cardiac dis., cancer & stroke appear to hv increased.
Q.671. How could a living unrelated donor share in R.Tx.?
A. Trials to increase No. of available kidney allografts including the use of living kidney donors. This including: kidney donation by biologically unrelated persons. Ethical considerations é living unrelated organ donation in U.S. are somewhat similar to those involved in living related organ donation. So far, living unrelated kidney donation has been based upon altruistic ideals and has not been driven by economic incentives. Basic medical evaluation🠞same as living related donors. A major concern é living donors 🠞long-term impact of having a solitary kidney.
Outcomes fr. HLA-mismatched pairing are similar to haploidentical relatives. One-y. values are comparable to living-related donors & better than é deceased donor kid.. Multiple efforts to expand living unrelated donor pool, e.g. paired-kidney-exchange program & non-directed live-kidney donor (altruistic donors or "good samaritan" donors) 🠞to donate a kidney, but do not identify sp. recipient. Incr. living donation rates, related/unrelated, needs to improve ptn. education.
Q.672. How could you evaluate a living kidney donor?
A.Thorough medical, surgical & psychosocial evaluation of prospective donor is performed. In U.S.,“Independent Living Donor Advocate” is mandated: a separate person é clear understanding of Tx. to promote the best interest of the potential donor, advocate for his rights & assist the donor to obtain & understanding information regarding: [consent & evaluation, surgical procedure]. “Purpose of evaluation”🠞ensure donor is in good health, has normal kid. function, structure & not a risk to dis. transmission. So, large No. of clinical tests us. performed for donor evaluation. Donor may be accepted, excluded, or require more assessment. There’re a signif. No. of generally accepted absolute C.I.. There’s also inter-center variability in relative exclusion criteria for donation. Decision-making is a nuanced one & incorporates donor autonomy (D.A.), which’s determined by donor’s risk understanding, relationship to recip. & benefit of donation.
Since black & Hispanic donors are more likely to develop CKD, H.T.& D.M. after donation comp.to white donors, African-American & Hispanics should be counseled regarding these findings by living donor advocate. Also, African-American or Hispanic ethnicity, we recommend utilizing the most conservative assessment of GFR, 24-h. ambulatory B.P. monitoring & glucose tolerance testing. Women of child -bearing age underwent nephrectomy adverse effect upon future pregnancies: [fetal loss, gestational D.M., gestational H.T. & pre-eclampsia] é pregnancy after kid. donation. So, it’s recommended: women should have completed planned child-bearing prior to donation. Nevertheless, the generally good outcomes should not exclude donors who have not completed child-bearing.
Q.673. What are the absolute contraindications for kidney donation " What are the“relative contraindications”?
A. Absolute contraindications including:
1) Proteinuria and/or hematuria.
2) Impaired renal function (defined as GFR <80 mL/min/1.73 m2).
3) Markedly abn. urologic & renal vascular abn.
4) Active infection.
5) Ch. active viral infec. (HIV, HTLV, Hepatitis B & C virus)
6) Active malignancy.
7) Hist. of malignancy: lung, breast, R., urologic, G.I., melanoma, etc.
8) Ch. illness: Pulm., liver, autoimmune, neurologic, or cardiac dis.
9) Clinically significant H.T..
11) Nephrocalcinosis, bilateral kid. stones, or recurrent nephrolithiasis
12) Poorly controlled psychosis.
13) Active substance abuse.
15) Diso. requiring anticoagulation .
- Relative C.I. to kid. donation, incl. the foll.:
1) Active peptic ulcer dis..
2) History of nephrolithiasis
3) Urological abnormals (eg, multiple renal vessels)
4) Morbid obesity, most commonly defined as B.M.I.>35 y.
5) Age >65 or <18 y.s
6) Strong F.H. of D.M. or H.T.
7) F.H. of renal cell cancer.
8) ABO or HLA incompatibility, wch may allow for Dsz.
Exclusion criteria: older age; borderline/mild H.T., borderline/ low GFRØ variable. Risk of D.M.: F.H. of D.M., gestational D.M., FBS strictly observed. Exclusion criteria based upon FBS or OGTT. varies by Tx. center. Obtaining H.B. A1C or a formal OGTT may also be used to assess presenseor risk for D.M. . " Age: Previously, older donors, (50 y), were not considered suitable. However, kidn. fr. such donors are now commonly used if these individuals are in good physiccal & mental condition & hv adequate kid. function. In U.S. almost 60 % of centers hd No upper age limit for kid. donors. As regard lower age limit, most centers report: an age < 18 y. is an absolute exclusion criterion. " Renal function: Most centers recomm. GFR of at least 80 mL/min. If R. function Eval-uated via a cr.cl., adequacy of 24 h. urine collection shd be carefully assessed. Furthermore, dietary intake of protein should be at least 1 g of protein/kg/B.W., since a low protein diet may Cr.Cl. by as much as 10 mL/min. Difficulties to get accur-ate Cr.Cl., incl. variability in urine collections spurious results. Some centers use estimated GFR e.g. MDRD equation for initial screen. Donors é GFR< 80 mL/min by initiallyisotopic scan. DRD-epi🠞GFR more accurately thn MDRD equation among those é true GFR > 60 mL/min. How ever, equations are frequently inaccurate. Ideally, protein excretion should be on ¸ 24 h. collection. Some centers use spot ur. protein/cr. ratio or microalbumin/Cr. ratio. Most centers exclude ptn é 300 mg/d., while others hv lower threshold of >150 mg/d. Definition of hematuria vary é each center. In U.S., some centers define hematuria as at least 10 RBC/hpf, while others: 3 RBC/hpf. Others only accept donor é hematuria if urologic evaluation & R. biopsy are -ve. H.T.: Alth. florid H.T. is clearly a C.I. for donation, precise risk to donors é border-line H.T. & those é F.H. of H.T. is less clear. Larger Tx. centers tend to use such donors é greater frequency thn those é smaller programs. History of nephrolithiasis: In U.S., majority of Tx. centers accept a donor é P.H. of nephrolithiasis if evaluation reveals abs. of stones & Normal metabolic studies.