Introduction of laparoscopic nephrectomy for autosomal dominant polycystic kidney disease as the standard procedure.

PURPOSE: Autosomal dominant polycystic kidney disease (ADPKD) is a common hereditary disorder and accounts for 5-10% of all cases of kidney failure. 50% of ADPKD patients reach kidney failure by the age of 58 years requiring dialysis or transplantation. Nephrectomy is performed in up to 20% of patients due to compressive symptoms, renal-related complications or in preparation for kidney transplantation. However, due to the large kidney size in ADPKD, nephrectomy can come with a considerable burden. Here we evaluate our institution's experience of laparoscopic nephrectomy (LN) as an alternative to open nephrectomy (ON) for ADPKD patients. MATERIALS AND METHODS: We report the results of the first 12 consecutive LN for ADPKD from August 2020 to August 2021 in our institution. These results were compared with the 12 most recent performed ON for ADPKD at the same institution (09/2017 to 07/2020). Intra- and postoperative parameters were collected and analyzed. Health related quality of life (HRQoL) was assessed using the SF36 questionnaire. RESULTS: Age, sex, and median preoperative kidney volumes were not significantly different between the two analyzed groups. Intraoperative estimated blood loss was significantly less in the laparoscopic group (33 ml (0-200 ml)) in comparison to the open group (186 ml (0-800 ml)) and postoperative need for blood transfusion was significantly reduced in the laparoscopic group (p = 0.0462). Operative time was significantly longer if LN was performed (158 min (85-227 min)) compared to the open procedure (107 min (56-174 min)) (p = 0.0079). In both groups one postoperative complication Clavien Dindo ≥ 3 occurred with the need of revision surgery. SF36 HRQol questionnaire revealed excellent postoperative quality of life after LN. CONCLUSION: LN in ADPKD patients is a safe and effective operative procedure independent of kidney size with excellent postoperative outcomes and benefits of minimally invasive surgery. Compared with the open procedure patients profit from significantly less need for transfusion with comparable postoperative complication rates. However significant longer operation times need to be taken in account.

Prospective Analyses of Circulating B Cell Subsets in ABO-Compatible and ABO-Incompatible Kidney Transplant Recipients.

Immunosuppressive strategies applied in renal transplantation traditionally focus on T cell inhibition. B cells were mainly examined in the context of antibody-mediated rejection, whereas the impact of antibody-independent B cell functions has only recently entered the field of transplantation. Similar to T cells, distinct B cell subsets can enhance or inhibit immune responses. In this study, we prospectively analyzed the evolution of B cell subsets in the peripheral blood of AB0-compatible (n = 27) and AB0-incompatible (n = 10) renal transplant recipients. Activated B cells were transiently decreased and plasmablasts were permanently decreased in patients without signs of rejection throughout the first year. In patients with histologically confirmed renal allograft rejection, activated B cells and plasmablasts were significantly elevated on day 365. Rituximab treatment in AB0-incompatible patients resulted in long-lasting B cell depletion and in a naïve phenotype of repopulating B cells 1 year following transplantation. Acute allograft rejection was correlated with an increase of activated B cells and plasmablasts and with a significant reduction of regulatory B cell subsets. Our study demonstrates the remarkable effects of standard immunosuppression on circulating B cell subsets. Furthermore, the B cell compartment was significantly altered in rejecting patients. A specific targeting of deleterious B cell subsets could be of clinical benefit in renal transplantation.

[Kidney transplantation in old age]. / Nierentransplantation im Alter.

Older patients clearly benefit from a kidney transplantation despite multiple comorbidities and complications, particularly with respect to life expectancy. Older patients remaining on dialysis on average die earlier compared to patients who underwent a kidney transplantation. In addition, patients experience a significant increase in the quality of life after renal transplantation. However, every patient has to be thoroughly evaluated to assess the individual benefits of a renal transplantation. Geriatric tools are particularly helpful to evaluate the suitability of older individuals. In 1999 the Eurotransplant senior program (ESP or "old for old") was initiated, aiming at shortening waiting time and cold ischemia time for patients on the waiting list. In this program, kidneys of donors aged 65 years and older are locally allocated to recipients also of 65 years and older. The results in ESP are promising, to the effect that this program helps older patients to receive a kidney transplant earlier than by the normal procedure; however, a better alternative to the ESP program is living donor transplantation, provided that a suitable donor is available. There is no age limit for the evaluation of potential donors. Compared to deceased donor kidney transplantation a living donor kidney will most likely function with a higher spontaneous rate and for a longer period of time and therefore provides a clear advantage for older recipients.

Proteinuria in systemic sclerosis: reversal by ACE inhibition.

In systemic sclerosis (SSc), kidney damage is a major clinical problem which can lead to a deleterious outcome. Recently, in diabetes mellitus, early detection of proteinuria and treatment with angiotensin-converting enzyme (ACE) inhibitors has been shown to slow progression of kidney disease and to improve prognosis. In this study, we investigated the spontaneous course of proteinuria in SSc and the effects of ACE inhibitor therapy. Proteinuria was determined in SSc patients with urine protein electrophoresis. SSc patients with proteinuria (n = 31) were followed over a median of 12 months. Of all 31 patients with pathologic urine protein electrophoresis investigated in this study, 9 patients (29 %) had additional microalbuminuria and 4 patients (12.9 %) showed increased total urinary protein. ACE inhibitor treatment was subsequently given to 23 patients. A total of 8 patients remained untreated for various reasons. Proteinuria resolved in 74 % of patients treated with ACE inhibitors, whereas in the untreated group, remission was observed only in 25 % (p = 0.014). Improvement of proteinuria was predominantly achieved in patients with recently diagnosed proteinuria and short disease duration. In patients with SSc and proteinuria, initiation of ACE inhibitor therapy resulted in a significant decrease in proteinuria.

[White matter lesions, young age, female--differential diagnosis of multiple sclerosis and juvenile stroke]. / Marklagerläsionen, junges Alter, weiblich--zur Differenzialdiagnose von Multipler Sklerose und juvenilem Schlaganfall.

Fabry's disease is an X-chromosomal linked recessive lysosomal storage disease caused by a deficiency of α-galactosidase A. Accumulation of toxic levels of sphingolipids leads to metabolic dysfunction in various cell types (endothelial cells, myocytes, fibroblasts) and organs thus causing a variety of symptoms. Neurological manifestations include recurrent strokes and polyneuropathy, many patients complain of pain or vertigo. The presentation of these polymorphic symptoms mostly at young age often leads to incorrect diagnosis and mistreatment. Here we report two cases of female patients who both were misdiagnosed and thus mistreated for many years. These case-reports aim in increasing the awareness for Fabry's disease as a differential diagnosis, especially in young women presenting with white matter lesions.

Elasmobranchs from Indonesian Waters: Feeding Ecology and Trypanorhynch Cestode Fauna Composition to Support Efforts in Shark and Ray Conservation.

PURPOSE: The stomachs and spiral valves of sharks and rays were examined for their trypanorhynch (Cestoda) parasite fauna and dietary items to infer feeding ecology. In Indonesia, sharks and rays have been experiencing increasing awareness and conservation in the recent years due to high fisheries activities and to avoid future species extinction. METHODS: The samples were collected in 2009 from two different sampling sites at the southern coasts of Java and Bali in Indonesia. The parasite fauna was studied for 41 elasmobranch fishes. Amongst these, three shark species, Carcharhinus sorrah, Carcharhinus sp. I and Squalus megalops and seven ray species, Brevitrygon heterura, B. cf. heterura, Gymnura zonura, Maculabatis gerrardi, Mobula kuhlii, Neotrygon cauruleopuncatata and Rhinobatos penggali were studied. Four additional specimens, belonging to the shark species Carcharhinus sp. II and Mustelus cf. manazo and the ray species Maculabatis gerrardi were studied from the waters of South Bali. RESULTS: Analyses of the feeding ecology of the ray M. gerrardi revealed distinct differences between both sampling sites, indicating the presence of ecological differences between the geographically independent regions. A total of 11 different trypanorhynch species/taxa belonging to the five families Eutetrarhynchidae (5), Gilquiniidae (1), Lacistorhynchidae (1), Pterobothriidae (1) and Tentaculariidae (3) were found. Ten trypanorhynch species from Penyu Bay and four species from South Bali could be identified. Two taxa that might represent new species were collected: Dollfusiella sp. from Brevitrygon heterura and Prochristianella sp. from Maculabatis gerrardi. CONCLUSIONS: The present paper gives insights in using the trypanorhynch cestode community in combination with feeding ecology analyses to support conservation of elasmobranchs in Indonesian waters.

Correlation Between the Transplant Evaluation Rating Scale (TERS) and Medical Outcomes in Living-Donor Kidney Transplant Recipients: A Retrospective Analysis.

BACKGROUND: Pretransplant psychosocial evaluation of living-donor kidney transplantation (LDKT) candidates identifies recipients with potentially inferior posttransplant outcomes. Rating instruments, based on semi-standardized interviews, help to improve and standardize psychosocial evaluation. The goal of this study was to retrospectively investigate the correlation between the Transplant Evaluation Rating Scale (TERS) and transplant outcome in LDKT recipients. METHODS: TERS scores were retrospectively generated by 2 raters based on comprehensive interviews of 146 LDKT recipients conducted by mental health professionals (interrater reliability, 0.8-0.9). All patients were eligible for transplantation according to pretransplant psychosocial evaluation. Patients were classified into 2 groups according to their TERS scores, in either two thirds excellent risk (TERS <29) and one third at least moderate risk (TERS ≥29) candidates. Analyzed medical parameters were change in estimated glomerular filtration rate and acute rejection (AR) episodes within the first year posttransplant. In addition, a subgroup of 65 patients was tested for de novo donor-specific HLA antibodies (DSA) posttransplant. RESULTS: There was no significant difference between the excellent (n = 97) and at least moderate (n = 49) risk candidates according to TERS in terms of organ function (estimated glomerular filtration rate decline >25%: 17 of 97 vs 11 of 49; P = .51) and episodes of AR (19 of 97 vs 15 of 49; P = .15). Patients developing de novo DSA (n = 18 [28%]) did not have higher pretransplant TERS scores (DSA positive, 11 of 42 vs 7 of 23; P = .78). CONCLUSIONS: Classifying LDKT recipients according to TERS score did not predict medical outcome at 1 year posttransplant or the occurrence of de novo DSA.

Postoperative Continuous Infusion of Local Anesthesia in Hand-Assisted Retroperitoneoscopic Living Donor Nephrectomy.

INTRODUCTION: Postoperative pain management in living kidney donor nephrectomy plays a key role in donor comfort and is important for the further acceptance of living kidney donation in times of organ shortage. Standard pain treatment (SPT) based on opioids is limited due to related side effects. Continuous infusion of local anesthesia (CILA) into the operative field is a promising alternative. The aim of this study was to evaluate whether CILA could reduce the dose of opioids in living kidney donors operated with hand-assisted retroperitoneoscopic donor nephrectomy (HARP). METHODS: An observational study on 30 living donors was performed. The primary outcome was the difference of morphine equivalents (MEQ) administered between CILA and SPT. RESULTS: On day 0 and 1, living donors with CILA received significant less MEQ compared to the SPT group, although on day 1 this effect was not statistically significant (day 0: 6.3 mg, interquartile range [IR] 4.2-11.2 vs 16.8 mg, IR 10.5-22.1, P = .009; day 1: 5.25 mg, IR 2.1-13.3 vs 13.3 mg, IR 6.7-23.8, P = .150). On days 2 and 3 there was no difference (day 2: 13.3 mg, IR 0.0-20.0 vs 13.3 mg, IR 6.7-13.3, P = .708; day 3: 13.3 mg, IR 0.0-26.7 vs 13.3 mg, IR 6.7-20, P = .825). Overall (days 0 to3) MEQ was also less for CILA without reaching statistical significance (39.6 mg, IR 10.9-70.5 vs 59.6 mg, IR 42.4-72.9, P = .187). CONCLUSIONS: CILA seems to be an effective instrument for donor pain management in the first 24 hours after HARP. Its effect abates by 48 hours after surgery, especially if highly potent nonopioids are given.

Role of nonconserved charged residues of the AE2 transmembrane domain in regulation of anion exchange by pH.

The ubiquitous AE2/SLC4A2 anion exchanger is acutely and independently regulated by intracellular (pH(i)) and extracellular pH (pH(o)), whereas the closely related AE1/SLC4A1 of the red cell and renal intercalated cell is relatively pH-insensitive. We have investigated the contribution of nonconserved charged residues within the C-terminal transmembrane domain (TMD) of AE2 to regulation by pH through mutation to the corresponding AE1 residues. AE2-mediated Cl(-)/Cl(-) exchange was measured as 4,4'-di-isothiocyanatostilbene-2,2'-disulfonic acid-sensitive (36)Cl(-) efflux from Xenopus oocytes by varying pH(i) at constant pH(o), and by varying pH(o) at near-constant pH(i). All mutations of nonconserved charged residues of the AE2 TMD yielded functional protein, but mutations of some conserved charged residues (R789E, R1056A, R1134C) reduced or abolished function. Individual mutation of AE2 TMD residues R921, F922, P1077, and R1107 exhibited reduced pH(i) sensitivity compared to wt AE2, whereas TMD mutants K1153R, R1155K, R1202L displayed enhanced sensitivity to acidic pH(i). In addition, pH(o) sensitivity was significantly acid- shifted when nonconserved AE2 TMD residues E981, K982, and D1075 were individually converted to the corresponding AE1 residues. These results demonstrate that multiple conserved charged residues are important for basal transport function of AE2 and that certain nonconserved charged residues of the AE2 TMD are essential for wild-type regulation of anion exchange by pH(i) and pH(o).

Acute regulation of mouse AE2 anion exchanger requires isoform-specific amino acid residues from most of the transmembrane domain.

The widely expressed anion exchanger polypeptide AE2/SLC4A2 is acutely inhibited by acidic intracellular (pH(i)), by acidic extracellular pH (pH(o)), and by the calmodulin inhibitor, calmidazolium, whereas it is acutely activated by NH(4)(+). The homologous erythroid/kidney AE1/SLC4A1 polypeptide is insensitive to these regulators. Each of these AE2 regulatory responses requires the presence of AE2's C-terminal transmembrane domain (TMD). We have now measured (36)Cl(-) efflux from Xenopus oocytes expressing bi- or tripartite AE2-AE1 chimeras to define TMD subregions in which AE2-specific sequences contribute to acute regulation. The chimeric AE polypeptides were all functional at pH(o) 7.4, with the sole exception of AE2((1-920))/AE1((613-811))/AE2((1120-1237)). Reciprocal exchanges of the large third extracellular loops were without effect. AE2 regulation by pH(i), pH(o) and NH(4)(+) was retained after substitution of C-terminal AE2 amino acids 1120-1237 (including the putative second re-entrant loop, two TM spans and the cytoplasmic tail) with the corresponding AE1 sequence. In contrast, the presence of this AE2 C-terminal sequence was both necessary and sufficient for inhibition by calmidazolium. All other tested TMD substitutions abolished AE2 pH(i) sensitivity, abolished or severely attenuated sensitivity to pH(o) and removed sensitivity to NH(4)(+). Loss of AE2 pH(i) sensitivity was not rescued by co-expression of a complementary AE2 sequence within separate full-length chimeras or AE2 subdomains. Thus, normal regulation of AE2 by pH and other ligands requires AE2-specific sequence from most regions of the AE2 TMD, with the exceptions of the third extracellular loop and a short C-terminal sequence. We conclude that the individual TMD amino acid residues previously identified as influencing acute regulation of AE2 exert that influence within a regulatory structure requiring essential contributions from multiple regions of the AE2 TMD.

Transmembrane domain histidines contribute to regulation of AE2-mediated anion exchange by pH.

Activity of the AE2/SLC4A2 anion exchanger is modulated acutely by pH, influencing the transporter's role in regulation of intracellular pH (pH(i)) and epithelial solute transport. In Xenopus oocytes, heterologous AE2-mediated Cl(-)/Cl(-) and Cl(-)/HCO(3)(-) exchange are inhibited by acid pH(i) or extracellular pH (pH(o)). We have investigated the importance to pH sensitivity of the eight histidine (His) residues within the AE2 COOH-terminal transmembrane domain (TMD). Wild-type mouse AE2-mediated Cl(-)/Cl(-) exchange, measured as DIDS-sensitive (36)Cl(-) efflux from Xenopus oocytes, was experimentally altered by varying pH(i) at constant pH(o) or varying pH(o). Pretreatment of oocytes with the His modifier diethylpyrocarbonate (DEPC) reduced basal (36)Cl(-) efflux at pH(o) 7.4 and acid shifted the pH(o) vs. activity profile of wild-type AE2, suggesting that His residues might be involved in pH sensing. Single His mutants of AE2 were generated and expressed in oocytes. Although mutation of H1029 to Ala severely reduced transport and surface expression, other individual His mutants exhibited wild-type or near-wild-type levels of Cl(-) transport activity with retention of pH(o) sensitivity. In contrast to the effects of DEPC on wild-type AE2, pH(o) sensitivity was significantly alkaline shifted for mutants H1144Y and H1145A and the triple mutants H846/H849/H1145A and H846/H849/H1160A. Although all functional mutants retained sensitivity to pH(i), pH(i) sensitivity was enhanced for AE2 H1145A. The simultaneous mutation of five or more His residues, however, greatly decreased basal AE2 activity, consistent with the inhibitory effects of DEPC modification. The results show that multiple TMD His residues contribute to basal AE2 activity and its sensitivity to pH(i) and pH(o).

[Gitelman's syndrome: an important differential diagnosis of hypokalemia]. / Gitelman-Syndrom: Eine wichtige Differenzialdiagnose der Hypokaliämie.

HISTORY AND CLINICAL FINDINGS: A 26-year-old woman presented with fatigue, muscle cramps and weakness. Since the age of 8 years she had moderate hypokalemia of unknown origin that was confirmed on multiple occasions. There was no family history of disease. INVESTIGATIONS: Laboratory tests showed moderate to severe hypokalemia with a serum potassium concentration of 2.7 to 3.0 mmol/l, hypomagnesemia, metabolic alkalosis and pronounced stimulation of the renin-angiotensin-aldosterone system. Despite normal serum calcium levels, urinary calcium excretion was below the detection threshold. Increased natriuresis was observed after administration of furosemide, but not after administration of hydrochlorothiazide. This finding pointed to the presence of a non-functional thiazide-sensitive sodium/chloride cotransporter in the distal convoluted tubule, characteristic for Gitelman's syndrome. Genetic analysis confirmed the diagnosis of Gitelman's syndrome and documented two heterozygous mutations in the gene encoding the sodium/chloride cotransporter. TREATMENT AND COURSE: The patient was treated with 160 mmol potassium and 30 mmol magnesium supplementation per day. Serum potassium was normalized and magnesium serum levels increased. Weakness and fatigue improved markedly. CONCLUSION: Gitelman's syndrome is an important differential diagnosis in the evaluation of the normotensive patient with hypokalemia.

Aldosterone resistance in kidney transplantation is in part induced by a down-regulation of mineralocorticoid receptor expression.

BACKGROUND: After renal transplantation immunosuppressive drugs-like cyclosporin A (CsA) and FK506 induce either hypoaldosteronism or pseudo-hypoaldosteronism presenting with hyperkalemia and metabolic acidosis. We investigated the relationship between renal allograft function under CsA therapy and plasma aldosterone concentration, potassium- and water homeostasis and mineralocorticoid receptor (MR) expression level in peripheral leukocytes. METHODS: We studied 21 renal transplant patients under CsA therapy and 12 healthy controls. Transplant recipients were studied before and under fludrocortisone treatment. Using quantitative reverse-phase polymerase chain reaction (RT-PCR) specific for the MR, we analyzed the level of expression of MR in peripheral leukocytes. RESULTS: In acidotic transplant recipients (HCO(3) 18.5 +/- 1.2 mM) renal function was only slightly impaired with 2.0 +/- 0.2 mg creatinine/dL when compared with 1.8 +/- 0.3 mg/dL (ns) in non-acidotic patients (HCO(3) 23.0 +/- 2.8 mM). Mean plasma aldosterone levels in renal transplant recipients did not differ from control levels (150 +/- 33 pg/mL vs. 148 +/- 33 pg/mL, ns). In contrast, the expression level of MR in peripheral leukocytes of renal transplant recipients treated with CsA was significantly decreased when compared with healthy controls without renal disease (120 +/- 78 vs. 423 +/- 73 RNA molecules/0.5 microg total RNA, p < 0.01). The level of expression of MR in renal transplant recipients did not differ between acidotic patients and non-acidotic patients (ns). The application of fludrocortisone reversed hyperkalemia and metabolic acidosis without significant effect on MR expression. CONCLUSIONS: The present data demonstrate that hyperkalemia and metabolic acidosis following CsA treatment in kidney transplantation might be associated with a down-regulation of MR expression on peripheral leukocytes. Electrolyte imbalance is reversible on application of fludrocortisone. This observation supports fludrocortisone treatment in transplant patients with severe electrolyte disturbances.