ESPN 50th Annual Meeting

ESPN 2017


 
Kidney transplantation in small children: A match-controlled risk assessment
Marcus Weitz 1 Guido F. Laube 1 Lars Pape 4 Luca Dello Strologo 3 Luisa Murer 5 Martin Konrad 8 Silvio Nadalin 13 Florian Thiel 7 Anja Büscher 9 Dominik Müller 11 Nicholas Webb 12 Bernd Hoppe 14 Martin Pohl 15 Therese Jungraithmayr 16 Michael Kaabak 17 Rezan Topaloglu 18 Heiko Billing 10 Kai Krupka 2 Burkhard Tönshoff 2 on behalf of the CERTAIN research network 6

1- University Children Hospital Zurich, Switzerland
2- Department of Paediatrics I, University Children’s Hospital, Heidelberg, Germany
3- Clinica Trapianto Renale Bambino Gesu, Rome, Italy
4- Children’s Hospital of the Medical High School, Hanover, Germany
5- Paediatric Nephrology Dialysis and Transplant Unit, Department of Paediatrics, , University of Padua, Padua, Italy
6- www.certain-registry.eu
7- University Children’s Hospital, Hamburg-Eppendorf. Germany
8- University Children’s Hospital, Muenster, Germany
9- University Children’s Hospital, Essen, Germany
10- University Children’s Hospital, Paediatrics I, Tübingen, Germany
11- Charité Campus Virchow Hospital, Paediatric Nephrology, Berlin, Germany
12- Royal Children’s Hospital, Manchester, UK
13- University Hospital Tuebingen, Germany
14- University Children’s Hospital, Bonn, Germany
15- University Children’s Hospital, Freiburg, Germany
16- Children’s Hospital, Memmingen, Germany
17- Boris Petrousky Scientific Center of Surgery RAMS, Moscow, Russia
18- Hacettepe University, Faculty of Medicine, Department of Pediatric Nephrology, Ankara, Turkey
 
Introduction:

Paediatric renal transplantation (RTx) is the treatment of choice for children with end-stage renal failure. Infants < 10 kg of body weight, however, represent a small patient group which is often not considered suitable for RTx. The objective of this retrospective, matched cohort study is the comparison of short-term outcomes (for 2 years post-transplant) in low-weight children (<10 kg) and in a control group of children with 10 -15 kg body weight at time of engrafting in order to refute or confirm the common current weight threshold (10 kg) for paediatric RTx.

Material and methods:

We conducted a multicentre, retrospective cohort study on paediatric renal transplant recipients with a body weight below 10 kg at RTx (low-weight group, n=38) compared to a matched control group (cases matched with two controls each) with a body weight of 10 -15 kg at RTx (control group, n=76) from data entered into the Cooperative European Paediatric Renal Transplant Initiative (CERTAIN) Registry. RTx from non-heart beating donors and AB0-incompatible transplantations were excluded. The matching criteria were as follows: (1) primary renal disease group (defined by risk of potential recurrence of primary renal disease and/or systemic organ impairment), (2) graft source (living or deceased donor), (3) immunosuppressive therapy (including calcineurin-inhibitor (cyclosporine microemulsion or tacrolimus), antiproliferative agent (mycophenolate mofetil (MMF) or azathioprine) with or without corticosteroids, and antibody induction therapy), and (4) number of HLA-mismatches (with a maximum difference of 1). Outcome variables were categorized as follows: (i) variables related to transplant surgery and the immediate postoperative period, (ii) transplant function (eGFR), (iii) number of treated acute rejection episodes (ARE) and (iv) transplant-related viral infections.

Results:

Cases and controls were well comparable regarding demographics and clinical characteristics beside the expected differences in anthropometric data. Surgical-related complications were rare and not significantly different (8% in the low-weight group, 17% in the control group; P=0.379) (Table 1).

Table 1. Outcome measures of the surgical transplant procedure

Complications

Low-weight group (n=38)

Control group (n=76)

P-value

Vascular

 

 

 

  Renal artery thrombosis

0 (0)

1 (1)

1.000

  Renal vein thrombosis

0 (0)

0 (0)

---

  Laceration of the renal artery

0 (0)

0 (0)

---

  Renal artery stenosis

0 (0)

0 (0)

---

Ureteral

 

 

 

  Leakage

0 (0)

0 (0)

---

  Obstruction

2 (5)

5 (7)

1.000

  Necrosis

0 (0)

0 (0)

---

Fluid collection

 

 

 

  Lymphocele

1 (3)

4 (5)

0.663

  Perirenal hematoma

0 (0)

0 (0)

---

  Seroma/urinoma

0 (0)

0 (0)

---

Miscellaneous*

 

 

 

  Graft compression

1 (3)

2 (3)

1.000

  Wound infection

1 (3)

1 (1)

1.000

Total *

3 (8)

12 (17)

0.379

* leading to surgical re-intervention.

 

For the first 2 years post-transplant, patient survival in both groups was 100% and graft survival 97% (P=1.00). Estimated GFR at 2 years post-transplant was excellent and not significantly different between groups (low-weight, 95±14 ml/min/1.73 m²; control, 94±12 ml/min/1.73 m²). The respective frequencies of ARE, arterial hypertension, CMV-, EBV- or BKV-replication, CMV disease and BK-virus associated nephropathy, and malignancies were comparable. EBV disease occurred more frequently in the low-weight group (p=0.003). 

Conclusions:

Our data demonstrate that RTx in low-weight children (<10 kg of body weight at time of engrafting) is associated with excellent graft function and overall outcome at 2 years post-transplant. It therefore represents a feasible option in these patients to potentially improve long-term outcomes, at least in selected centers with appropriate surgical and medical expertise.