2022 Recommendations of the AFU Lithiasis Committee: Medical management - from diagnosis to treatment

The morphological-compositional analysis of urinary stones allows distinguishing schematically several situations: dietary, digestive, metabolic/hormonal, infectious and genetic problems. Blood and urine testing are recommended in the first instance to identify risk factors of urinary stone disease in order to avoid recurrence or progression. The other objective is to detect a potential underlying pathology associated with high risk of urinary stone disease (e.g. primary hyperparathyroidism, primary or enteric hyperoxaluria, cystinuria, distal renal tubular acidosis) that may require specific management. Lifestyle-diet measures are the basis of the management of all stone types, but pharmacological treatments may be required. METHODOLOGY: These recommendations were developed using two methods: the Clinical Practice Recommendation (CPR) method and the ADAPTE method, depending on whether the question was considered in the European Association of Urology (EAU) recommendations (https://uroweb.org/guidelines/urolithiasis) [EAU 2022] and their adaptability to the French context.

POS1343 ABNORMAL ELECTROCHEMICAL SKIN CONDUCTANCE VALUES IN PATIENTS WITH AA AMYLOIDOSIS

Background:

Clinical manifestations are scarce in AA amyloidosis (AAA) and, contrary to other types of amyloidosis, involvement of the peripheral nervous system was rarely reported in AAA. However, the usual absence of hypertension despite chronic renal failure and the digestive involvement may be secondary to dysautonomia, but the autonomic nervous system has rarely been studied in AAA (1). Measure of the electrochemical skin conductance (ESC) is a simple and reproducible method to evaluate the function of eccrine sweat glands, which are innervated by small non-myelinated C fibers, and patients with AL and hereditary transthyretin amyloidoses show decreased ESC values (2,3).

Objectives:

To evaluate ESC values by Sudoscan in patients with AAA.

Methods:

Patients diagnosed as having AAA based on positive immunohistochemistry with an anti-serum amyloid A antibody followed at the national reference center for AAA in Tenon Hospital between July, 2017 and September, 2020, were routinely assessed for ESC with FDA approved Sudoscan (Impeto Medical, Paris, France). An ESC value above 60 microSiemens (µS) or 70 µS were considered normal for hands or feet, respectively. Categorical variables are reported as percentages and continuous variables are expressed as means±standard deviation. Correlations between age, body mass index (BMI), hemoglobin levels, C-reactive protein levels, estimated glomerular filtration rate using the Chronic Kidney Disease Epidemiology Collaboration equation (defined as 0 for dialysis patients) and ESC values were calculated using the nonparametric Spearman test. GraphPad Prism Version 7 software (GraphPad Software, San Diego, California, USA) was used for statistical analyses. A p-value <0.05 was considered as statistically significant.

Results:

Overall, 32 patients (16 women) were included, with a mean age of 57.4±13.6 years and a mean BMI of 25.2±6.8 kg/m2. Six (19%) had diabetes mellitus, and 5 (16%) had a kidney transplantation. The main causes of AAA were: monogenic autoinflammatory diseases (n=11, 34%, including 9 patients with familial Mediterranean fever), chronic and/or recurrent infections (n=5, 16%), obesity (n=3, 9%) and undefined (n=3, 9%). The mean hands’ ESC values was normal at 65.5±21.1 µS, although 8 (25%) patients had ESC values below 60 µS, including 2 diabetic patients. In contrast, the mean feet’s ESC values was abnormal at 62.7±23.7 µS, including half of the patients with ESC values below 70 µS (2 diabetic patients). Eight patients had abnormal ESC values only for feet, and 1 had abnormal values only for hands. Apart from a significant correlation between feet and hands’ ESC values (p<0.0001), only the estimated glomerular filtration rate was significantly associated with hands’ ESC values (p<0.01).

Conclusion:

To our knowledge, this is the first study to assess ESC in AAA. Feet’s ESC values were moderately impaired in half of the patients with AAA. Therefore, this study reinforces the previously reported alterations in the autonomic nervous system in patients with AAA that should probably be searched for in these patients. In addition, the identification of an alteration of the ESC values cannot allow to distinguish the type of amyloidosis.

References:

[1]Nussinovitch U, Volovitz B, Nussinovitch M, Lidar M, Feld O, Nussinovitch N, et al. Abnormal heart rate variability in AA amyloidosis of familial Mediterranean fever. Amyloid 2011;18:206–10.

[2]Montcuquet A, Duchesne M, Roussellet O, Jaccard A, Magy L. Electrochemical skin conductance values suggest frequent subclinical autonomic involvement in patients with AL amyloidosis. Amyloid 2020;27:215–6.

[3]Fortanier E, Delmont E, Verschueren A, Attarian S. Quantitative sudomotor test helps differentiate transthyretin familial amyloid polyneuropathy from chronic inflammatory demyelinating polyneuropathy. Clin Neurophysiol 2020;131:1129–33.

Disclosure of Interests:

None declared

Calcium oxalate precipitation by diffusion using laminar microfluidics: toward a biomimetic model of pathological microcalcifications

The effect of mixing calcium and oxalate precursors by diffusion at miscible liquid interfaces on calcium oxalate crystalline phases, and in physiological conditions (concentrations and flow rates), is studied using a microfluidic channel. This channel has similar dimensions as the collection duct in human kidneys and serves as a biomimetic model in order to understand the formation of pathological microcalcifications.

[Prophylactic prescription of low-molecular-weight heparin in the non-surgical setting: impact of recommendations]

OBJECTIVE

Low-molecular-weight heparins (LMWH) had official approval for use for venous thromboembolism prophylaxis only for surgery patients when this survey was conducted, but were nevertheless often used in non-surgery patients. We conducted this "before and after" survey from May 1998 to April 1999 to assess the impact of the recommendations implemented in the beginning of 1999.

METHODS

Data on the use of LMWH were collected on three different days within a three week interval in all non-surgery departments at the Tenon hospital before distribution of expert recommendations early in 1999. Published in La Presse Médicale in January 2000, these recommendations issued from an external panel of 43 experts who were contacted to establish a consensus opinion using the Delphi method. Data were again collected on three different days after implementation of the recommendations. Implementation was based on a patient-specific prescription order form requested by the hospital pharmacy for delivery to the department.

RESULTS

Data were collected for 121 prescriptions prior to the recommendations and for 158 after. Sex-ratio, mean age and percentage of LMWH prescriptions did not differ significantly between the two periods. There was a lower number of non-appropriate prescriptions after implementation of the recommendations from 54.5% to 35.4% (p = 0.01) with better conformity for recommendation A (high-risk patients) (36% versus 43%, NS) and for recommendation B (= 2 risk situations or = 1 risk situation and = 2 aggravating factors) (10% versus 22%, p = 0.01). Better conformity of LMWH prescriptions in oncology and radiotherapy departments partially explained this general improvement, but the difference remained significant when excluding these two departments (p = 0.04).

CONCLUSION

This study shows that physician compliance with recognized expert recommendations can improve their implementation. This procedure is now in general use in the Tenon hospital.

Acute renal failure in patients over 80 years old: 25-years' experience

OBJECTIVE

To determine the epidemiological trends, spectrum of etiologies, morbidity and mortality of acute renal failure (ARF) in patients over 80 years old.

DESIGN

Historical cohort analysis.

SETTING

Intensive care unit (ICU) of nephrology, Tenon Hospital, Paris.

PATIENTS AND PARTICIPANTS

The criteria of inclusion was ARF, defined on the basis of a creatinine value over 120 mumol/l, in patients over 80 years of age admitted between October 1971 and September 1996. When moderate chronic nephropathy was pre-existing, ARF was defined by the increase of at least 50% over the basal creatininemia.

MEASUREMENTS AND RESULTS

Three hundred and eighty-one patients over 80 years of age were included. The etiology and mechanism of ARF are detailed. 29% of the patients received dialysis. Global mortality at the hospital was 40%. Factors significantly associated with a poor prognosis are identified. Mean survival after hospitalization was 19 months.

CONCLUSION

The frequency of admission to ICUs for ARF in patients older than 80 years seems to be on the increase. Mortality is less severe than expected. These patients could benefit from the renal replacement therapy of modern intensive care medicine.

[Intravenous polyclonal immunoglobulins (IVIG): what use in transplantation?]

Intravenous human polyclonal immunoglobulins G (IVIg) were initially used as substitutive therapy for primary and secondary immunodeficiencies then for various autoimmune diseases. More recently they were proposed in organ transplant recipients as they induce a decrease of the anti-HLA antibodies titer in HLA immunized patients. Few retrospective and prospective trials have been performed yet, though they clearly show a beneficial effect of IVIg on kidney graft survival. This paper reviews the different potential mechanisms of action of IVIg their use and potential efficacy in organ transplant recipients.

Bacterial endocarditis associated with crescentic glomerulonephritis in a kidney transplant patient: first case report

BACKGROUND

Endocarditis-induced crescentic glomerulonephritis is a well-described complication in nontransplant patients. Its occurrence in transplant patients has not been reported to date.

METHODS

A 50-year-old man who had received a renal allograft 13 years before and been treated with prednisone, 10 mg/day, was admitted for progressive renal failure, purpura, edema of the lower limbs, and fever.

RESULTS

Blood cultures isolated Streptococcus bovis and cardiac ultrasound examination revealed a 23-mm-large vegetation on the mitral valve. His plasma creatinine level was 478 micromol/L and his proteinuria was 5.5 g/day. A renal biopsy showed diffuse crescentic glomerulonephritis. Long-term antibiotic treatment and three methylprednisolone pulses were effective in treating the endocarditis and glomerulonephritis.

CONCLUSION

Endocarditis-induced glomerulonephritis is an immune-mediated disease that can also occur on a renal allograft. It is likely that a low daily dose of immunosuppressive treatment may have been a facilitating factor.

Long-term prognosis of renal transplantation after preemptive treatment of cytomegalovirus infection

A role for cytomegalovirus (CMV) infection in the etiologies of acute and chronic rejection in renal allograft recipients has been suggested. We previously reported that preemptive treatment of CMV infection with ganciclovir in kidney transplant patients was safe and effective. We now present a retrospective analysis of 169 consecutive renal transplant patients, of whom 87 (51.5%) received preemptive treatment with ganciclovir (CMV(+) group). No patient died of CMV infection. Actuarial graft and patient survival rates were not different between the CMV(+) and the CMV(-) groups (graft survival: 68% and 69%; patient survival: 89% and 88%, respectively). At the end of the study, the mean plasma creatinine levels were not statistically different between the two groups (185+/-13 and 166+/-12 micromol/L for the CMV(+) group and the CMV(-) group, respectively). These results suggest that preemptive treatment of CMV infection with ganciclovir may prevent the CMV-induced renal injury and graft loss.

Long-term benefit of intravenous immunoglobulins in cadaveric kidney retransplantation

Renal retransplantation can be hampered by the presence of anti-HLA alloantibodies. Previous studies have documented in vitro and in vivo suppression of these antibodies by intravenous immunoglobulins (IVIg). We conducted a randomized study in 41 patients, who have received a second cadaveric transplant between 1989 and 1994. They all were treated with a quadruple-immunosuppressive protocol. In addition, 21 patients received 0.4 g/kg/day of IVIg, on the first 5 days after transplantation. The two groups of patients were identical for age, sex, duration of the first graft, duration of cold ischemia, anti-HLA sensitization, HLA matching, the number of acute rejection episodes, and the incidence of cytomegalovirus infection. The 5-year survival rate was significantly higher in the group of patients treated with IVIg: 68% versus 50% in the control group. The only significant factor associated with IVIg infusion and better survival was a shorter delay of graft function (3.4 +/- 1.0 days versus 9.9 +/- 1.6 days). In conclusion, this randomized study demonstrates that IVIg treatment is associated with better long-term graft survival in retransplanted patients. This beneficial effect may be related to a long-lasting immunosuppressive effect of IVIg and/or to an early protective effect of the graft against ischemia.

Suppression of HLA-specific alloantibodies by high-dose intravenous immunoglobulins (IVIg). A potential tool for transplantation of immunized patients

Renal transplantation in patients presenting end-stage renal failure can be hampered by the presence of alloantibodies against HLA antigens. In 4 out of 5 patients with HLA-specific alloantibodies waiting for a renal allograft, treatment with high-dose i.v. Ig resulted in a prolonged suppression (over 3 months) of most of the panel-reactive anti-HLA antibodies (PRA). Intravenous polyclonal human Ig (IVIg) and F(ab')2 fragments from IVIg inhibited the binding of patients' plasma and IgG fractions to peripheral blood lymphocytes from normal donors as well as their cytotoxicity, suggesting that the in vivo effect of IVIg was mediated by the presence, in the IVIg preparation, of anti-idiotypes directed against idiotypes borne on the anti-HLA antibodies. Thus, treatment with IVIg can be a valuable tool toward the transplantation of immunized patients.