MO906: Antibody Response to COVID-19 Vaccination in Patients Under Dialysis

BACKGROUND AND AIMS

Patients (pts) with end-stage kidney disease (ESRD) may be more vulnerable to infections and may have a suboptimal response to vaccination. Dialysis patient (pt) began to be vaccinated against COVID-19 in February 2021. However, there were many doubts about whether immunization would be effective for them, as these pts have an impaired immune system, and it seems that this population responds poorly to vaccinations. Serum neutralizing antibodies (AbN) rapidly appear after the SARS-CoV-2 infection and the vaccination and are maintained for several months. The emergence of SARS-CoV-2 variants has raised concerns about the breadth of the neutralizing antibody responses.

METHOD

Serum samples were obtained from 181 patients receiving dialysis. Levels of circulating SARS-CoV-2 anti-spike IgG(S) and anti-nucleocapsid IgG (N) antibodies were quantified using the Abbott Diagnostics SARS-CoV-2 IgG chemiluminescent microparticle immunoassay (Abbott Diagnostics, Abbott Park, IL, USA) on an Abbott Diagnostics Architect i2000 SR and an Alinity analyzer, according to the manufacturer's instructions. Serum neutralizing antibodies (AbN) by commercially available assays (cPass SARS-CoV-2 Neutralization Antibody Detection Kit), at the first and the third months after the vaccination, were identified.

RESULTS

The IgG-spike Abs had a statistically significant decrease at 3 months after the vaccination in relation to the measurements 1 month after that.

AbN had a statistically significant decline at 3 months after the vaccination in relation to the measurements 1 month after. Pts with cardiovascular disease (CD) had significantly lower levels of antibodies than those who did not have CD. Additionally, CD was an aggravating factor in combination with the other comorbidities for the development of antibodies. Pts with a history of malignancy had significantly lower levels of antibodies in relation to those who did not. Those under therapy with antihistamines in the 1st month after the vaccination presented a statistically lower level of the AbNs, but this difference did not exist in the measurements 3 months after vaccination. There was a correlation between the AbNs and the age, also between the time these patients underwent dialysis. Those who had COVID-19 infection presented higher levels of the antibodies AbN/IgG-spiked Ab at 3 months.

CONCLUSION

It is presented that the IgG-spike Abs and the AbN had a statistically significant decrease at 3 months after the vaccination, which shows the importance of completing vaccination with the third dose after 3 months. Also, it is presented that CD is a risk factor for lower levels of Abs. Randomized clinical trials for COVID-19 vaccines included a few patients with kidney disease; therefore, the vaccine immunogenicity is uncertain in this population.

MO622: Clinical Value of Kidney Biopsy in Patients with Diabetes Mellitus and NephroticRange Proteinuria: Correlation of Clinical and Laboratory Findings with Histopathological Data

BACKGROUND AND AIMS

Diabetes mellitus (DM) is tightly associated with the increased prevalence and rapid evolution of diabetic nephropathy (DN). Interestingly, deterioration of kidney function in diabetic patients is often nonetheless caused by other factors besides DM and frequently goes undiagnosed. Nondiabetic renal disease (non-DRD) could be suspected in case of rapid progression of renal function impairment and/or severe, nephrotic-range proteinuria. While biopsy of the kidneys is the ‘gold standard’ of the diagnostic approach in such cases, no real consensus exists regarding the profile of diabetic patients with renal disease and proteinuria, who should be submitted to kidney biopsy. Thus, this study intends to correlate the clinical and biochemical profile of diabetic patients with deteriorated kidney function to the histopathological data of a kidney biopsy and allows early differentiation between DN and non-DRD based on the results of kidney biopsy.

METHOD

A total of 32 patients, who were treated in our outpatient's diabetes clinic from a multidisciplinary team of endocrinologists and nephrologists at Evangelismos General Hospital, were retrospectively studied. All patients suffered from DM2 and presented with nephrotic-range levels of proteinuria. Biochemical data of glycemic control and renal function, clinical findings related to DN and histological findings of kidney biopsy were documented. All patients were submitted to kidney biopsy and depending on the histopathologic findings were categorized into three groups: (i) genuine diabetic nephropathy (GDN), (ii) renal disease due to cause other than diabetes mellitus (ODMRD) and (iii) mixed renal disease (MRD).

RESULTS

Among the 32 patients, 15 (46.9%) had findings of a GDN, while 17 patients (53.1%) suffered from ODMRD (13 patients) or MRD (4 patients). All patients were hypertensive. The patients with GDN were younger (54.1 versus 68.2 versus 70.5 years, P = 0.016) and had a higher HbA1C value (7.9 versus 6.5 versus 6.8%, P = 0.069) at the time of the kidney biopsy in comparison to the ODMRD and MRD patients. On the contrary, ODMRD patients had significantly smaller disease duration compared with the GDN and MRD groups (8.4 versus 11.6 versus 13.3 years, P = 0.04). Furthermore, the incidence of diabetic retinopathy was greater among patients with GDN and MRD in comparison to the ODMRD patients (60 versus 75 versus 7.6%, P < 0.01). Additionally, interstitial fibrosis was significantly more prevalent among the patients with GDN in comparison to those with ODMRD and MRD, respectively (73.3 versus 38.4 versus 50%, P = 0.02). Finally, the presence of diabetic retinopathy {OR 4.88, [95% confidence interval (CI) 1.06–22.38], P = 0.04}, higher levels (>25%) of interstitial renal fibrosis [OR 5.71 (95% CI 1.16–28.1), P = 0.032] and longer DM2 duration (>10 years) [OR 5.04, (95% CI 1.1–22.96), P = 0.036] were recognized as factors, which were positively associated with GDN.

CONCLUSIONS

This study highlights emphatically the usefulness of the kidney biopsy and its histopathological findings in case of patients with diabetes mellitus and nephrotic-range levels of proteinuria. The value of a detailed and careful medical history seems to be critical for the early diagnosis of the type of kidney disease in diabetic patients. It is crucial to early differentiate the patients who suffer from nondiabetic nephropathy, from those with diabetic nephropathy and initiate the appropriate therapy, according to the underlying cause. Thus, the detection of nephrotic-range levels of proteinuria in diabetic patients should lead to kidney biopsy especially in case diabetic retinopathy is not present and longer disease duration is observed. Finally, the existing criteria/indications for a kidney biopsy in diabetic patients with nephrotic-range levels of proteinuria should be reconsidered or even revised.

MO134: Follow-Up of Patients with Vasculitis: A 10-year retrospective study

BACKGROUND AND AIMS

Vasculitis constitutes a systemic disease with renal involvement at almost 100% in microscopic polyangiitis, 70–80% in granulomatosis with polyangitiis, 25% in eosinophilic granulomatosis with polyangitiis and 40–50% appears as renal limited vasculitis. In order to describe our experience, we conducted a retrospective study of patients with vasculitis which we have been monitoring for the last 10 years.

METHOD

We studied the time of the remission, the use of plasma exchange (PLEX), the biopsy results as well as the time between the first symptoms and the initiation of the therapy.

RESULTS

The total number of patients was 59, 28 (47.5%) females, with a mean age of 66.08 ± 13.95 years. The median follow-up time was 70 weeks with IQR [64, 76]. The patients with positive pANCA/MPO were 38 (64.4%), while those with positive cANCA/PR3 were 10 (16.9%). The remaining nine patients (15.3%) suffered from ANCA negative vasculitis. The mean value of the initial creatinine was 4.53 ± 2.3 mg/dL and the median value of the eGFR CKD-EPI was 11 mL/min/1.73 m2, IQR [7, 17]. The PLEX was implemented auxiliary in 16 patients (27.1%) and in 32 patients (54.2%) pulse cortisone along with intravenous cyclophosphamide was preferred. The remission was accomplished in 32 patients (54.2%) with median time of 8 weeks, IQR [0, 17]. At least one relapse episode was noted in 8 patients (13.6%), 19 patients (32.2%) ended up in ESRD and 15 patients (25.4%) deceased during the follow-up time. The major cause of death was sepsis with 10 demises (66.7%), while 5 patients (8.4%) suffered from malignancies in general. The remission time was found to be dependent on the initial value of creatinine (P-value.023). There was no statistical significance regarding the findings of the biopsy and the outcome, the relapse rate or the remission time. There was also no correlation marked between the first symptoms and the initiation of the therapy. The plasma exchange failed to reduce the time until the remission, unless the patient was cANCA positive (P-value.036). Although the sample was limited, the patients with positive cANCA/PR3 submitted to PLEX were able to achieve the remission in 5.25 weeks contrary to those who received solely methylprednisolone and cyclophosmamide. The latter achieved remission in 21 (mean) weeks (LogRank test, P-vaue .001. The vasculitis type has no effect over the renal outcome or the relapse rate. No statistical significance was found between the PLEX and the relapse rate or the outcome. Patients do not benefit from auxiliary treatment with the PLEX, unless they have positive cANCA/PR3. However, the initial serum creatinine seems to affect the time of the remission.

CONCLUSION

There is indisputable need for a larger patient sample in order to safely conduct further results.

MO960RENAL TRANSPLANTATION FROM A LIVING DONOR WITH RENAL ARTERY FIBROMUSCULAR DYSPLASIA

Background and Aims

Renal transplantation is considered the most effective and less costly modality of renal replacement therapy in patients with end stage renal disease. The disparity between kidney allografts and recipients has led to a global effort to increase the pool of kidney donors. Accordingly, fibromuscular dysplasia (FMD) is no longer considered an absolute contraindication for kidney donation. The incidence of FMD is about 2.3%-5.8% in potential kidney donors. There are few cases in the literature where renal artery stenosis in allografts with known pre-transplantation FMD became worse after transplantation, indicating the importance of a proper follow up in the recipients.

This is a case of a living kidney donor with no history of hypertension, proteinuria or elevated serum creatinine, whose intra-arterial digital subtraction angiography revealed FMD lesions in the left renal artery.

Method

Case report

Results

A 54-year-old Caucasian female with medical history of hypothyroidism took the decision to offer her kidney to her 37-year-old son who was diagnosed with end-stage renal disease five years ago secondary to diabetes mellitus type I. She had no history for diabetes, hypertension and renal disease. Her vital signs on admission were heart rate of 78 beats/min and blood pressure of 130/70 mmHg. Urinalysis, biochemical profile and serological evaluations were all within normal ranges. Blood urea was 36 mg/dL and serum creatinine was 0.6 mg/dL (eGFR 97ml/min/1.73m2). The abdominal ultrasound and renogram with Tc-99m DTPA showed no remarkable findings. On intra-arterial digital subtraction angiography an abnormal succession of dilatations and multifocal stenoses of the left renal artery, characteristic of medial FMD, was found. The right renal artery was normal.

Apart from a dysfunctional permanent left femoral catheter, the patient had no other vascular access for hemodialysis because of Superior Vena Cava syndrome, so he needed urgent transplantation.

Taking all of these into consideration, the patient was offered renal transplantation as the best option. A left open donor nephrectomy was performed; the renal artery was divided distal to the stenotic dysplastic area. The allograft was placed at the right iliac fossa of the recipient with arterial and venous anastomosis to the extrarenal iliac vessels. Post-operatively, the recipient had a delayed graft function lasted 13 days. On renal artery Doppler in the allograft we found increased resistance index (RI) that gradually normalized without any intervention. An immunosuppressive regiment of tacrolimus, mycophenolate and prednisone was administered according to our center protocol. At discharge serum creatinine was 1.7 mg/dL (eGFR: 50ml/min/1.73m2).

At the year follow-up, the donor was normotensive and had near normal renal function (Cr:1.3mg/dL, eGFR: 70ml/min/1.73m2). The recipient has a well-controlled blood pressure receiving two antihypertensive drugs and maintains a satisfactory renal function.

Conclusion

Few cases with FMD in renal allografts from living and deceased donors have been described. In a review of 4 studies the authors concluded that the outcome of transplantation with allografts from living donors with medial FMD was satisfactory and these allografts could be used to increase the donor pool. Furthermore, it is strongly recommended to have a thorough pre-transplantation check of the donor as well as a close monitoring of both the donor and recipient after transplantation. This case shows that allografts harvested from carefully selected donors with renal arterial FMD can be successfully used, particularly in urgent conditions. Detailed pre-tranplantation imaging of donor’s renal arteries, selection of the appropriate screening method, as well as close monitoring of both donor and recipient for early interventions after transplantation is of paramount importance.

P1711RENAL RESISTIVE INDEX (RRI) OF KIDNEY ALLOGRAFT. OMEN OF THE OUTCOME OF TRANSPLANTION?

Background and Aims

Renal resistive index (RRI) of ultrasonography is a useful and potent tool for assessment and evaluation of renal hyperfiltration status of the transplanted patients. The aim of this study was to evaluate the association of RRI with renal function one year after transplant.

Method

We evaluated retrospectively 98 kidney allograft recipients. Data were collected from transplantations performed in our medical center between 01/2014 and 09/2018. Patients with acute loss of the renal function and renal survival less than a year were excluded from the study. We compared longitudinally the RRI at the first week after transplant and the third month, with glomerular filtration rate (eGFR, by CKD-EPI) at the end of the first year of transplantation. RRI was measured on the interlobular artery level, in each of the aforementioned time periods, and results were classified into 2 groups, RRI <0,8 or>0,8. In addition, age, gender and delayed graft function (DGF) were also determined in all patients.

Results

Sixty seven (67) of the recipients were males and 31 females with a mean age of 48±12years. The corresponding demographics for the donors were 46 males and 52 females with a mean age of 53 ±14. No correlations were found between RRI of the first week with gender and age, of both donors and recipients (p>0.05). Similarly, RRI of the first week was not correlated with DGF and one-year eGFR after transplant (p>0.05). On the contrary, RRI performed at the third month was strongly correlated to DGF and eGFR at the end of the first year. In other words, allograft recipients with a resistive index less than 0.80, had a higher eGFR and reduced frequency of DGF (p=0.01 and 0.03 respectively). Last but not least, higher recipient age and not gender was the main determinant of an increase of resistive index in the third month after transplant (P=0.02).

Conclusion

RRI offers interesting and helpful data on kidney allograft function. RRI of the third month less than 0.8 was related to better renal function at the end of the first year after transplant mainly and a lower incidence of DGF.

P0503PROGNOSTIC VALUE OF HISTOPATHOLOGICAL CLASSIFICATION OF ANCA-ASSOCIATED GLOMERULONEPHRITIS: A SINGLE-CENTER RETROSPECTIVE STUDY

Background and Aims

Kidney biopsy is the gold standard for establishing the diagnosis of ANCA-associated glomerulonephritis (GN). Previous studies have validated the prognostic significance of histopathological classification for the development of end stage renal disease (ESRD). We sought to evaluate the prognostic value of the EUVAS histopathological classification in terms of renal and overall survival (OS) in a single center retrospective cohort study.

Method

Forty-six consecutive patients (mean age 69, range; 29-84 years) with biopsy-proven ANCA-associated GN diagnosed at our hospital between January 2003 and January 2019 were included in the study. All biopsies had ≥10 glomeruli and were reviewed by two independent pathologists blinded to clinical data. Renal morphology was classified as sclerotic (if ≥50% globally sclerotic glomeruli), focal (if ≥50% normal glomeruli), crescentic (if ≥50% crescents with cellular component) and mixed. Probabilities of renal and overall survival were estimated using Kaplan-Meier method. Cumulative incidence function for ESRD was estimated using death as competing risk.

Results

Three biopsies were classified as focal (6%), twenty-nine as crescentic (63%), ten as mixed (22%) and four as sclerotic (9%). With a median follow-up of 39 months the 3-year probability of renal survival was 100% for the focal class, 66,37% for the crescentic class, 64% for the mixed class and 50% for the sclerotic class (p>0.05). Other parameters associated with increased probability of ESRD were interstitial fibrosis (IF) and eGFR at time of diagnosis. IF of ≥40% at diagnosis was associated with high incidence of ESRD, while IF of 20-40% and <20% had significantly lower incidence of ESRD (100% vs 34.2% vs 17.6%, p=0.014). Half (50%) of the patients with eGFR<15ml/min at diagnosis developed ESRD at 36 months compared to only 8% of the patients with eGFR≥15ml/min (p=0.024) at diagnosis. Median overall survival for the entire cohort reached 128 months (95% CI; 35-221). Twelve patients died at median time of 19,5 months (range; 3-129) after diagnosis. Three patients died before developing ESRD and nine patients developed ESRD prior to death. Leading cause of death was sepsis (8/12). Other causes included sudden death (n=2), malignancy (n=1) and intestinal obstruction (n=1). In terms of histopathological classification, OS at 3 years was 100% (95% CI; N/A) for the focal class, 73.5% (95% CI; 57-94.8) for the crescentic class, 100% (95% CI; N/A) for the mixed class and 37,5% (95% CI; 83,9-100) for the sclerotic class (p>0.05).

Conclusion

Our results suggest that the focal class has the best and the sclerotic the worst outcome, while both crescentic and mixed subtype are of intermediate risk. Although our results did not reach statistical significance, due to primarily the small number of patients included, the incidence of ESRD and the probability of renal survival in each histopathological subtype in our cohort are comparable to those reported by larger studies. Thus, the EUVAS histological classification of ANCA-associated glomerulonephritis appears to be a useful predictor of renal outcome at the time of diagnosis. As previously reported, no significant prognostic difference was observed between the crescentic and mixed subtype. Thus, this classification system should be optimized by inclusion of other histological characteristics, such as the specific percentage of normal glomeruli, tubular atrophy and interstitial fibrosis. These characteristics may prove useful in highlighting significant differences between mixed and crescentic classes.

Glomerular expression of matrix metalloproteinases in systemic lupus erythematosus in association with activity index and renal function

Purpose: The aim of this study was to examine the expression of matrix metalloproteinases (MMPs) MMP-1, MMP-2, MMP-3, MMP-9, and their specific tissue inhibitor TIMP-1 in kidney biopsies of patients with lupus nephritis (LN) and to investigate the relationship between MMPs, activity index, and renal function at the time of kidney biopsy.

Methods: We performed immunohistochemistry with monoclonal antibodies against MMP-1, MMP-2, MMP-3, MMP-9, and TIMP-1 in 58 kidney-biopsy specimens with LN (according to the 2004 ISN/RPS classification) and eight specimens from normal kidney tissue. We used clinical data of 36 patients at the time of kidney biopsy to evaluate the association between MMPs expression and renal function.

Results: We found increased MMP-1, MMP-2, and MMP-3 expression in LN glomeruli and a significant correlation with the activity features, with higher activity index score and worse renal function (p < .001). In particular, we have noticed a significant correlation of MMP-1 with leukocyte influx (OR:16.5 95%CI 4.3–62.5 p < .001), and MMP-3 with glomerular hypercellularity (OR:18.6 95%CI 4.8–72.8 p < .001). Moreover, we found a strong correlation of MMP-2 expression with fibrinoid necrosis and cellular crescents formation (OR:17.1 95%CI 4.3–67.7 p < .001).

Conclusions: MMP expression in renal biopsy of patients with LN is increased and directly related to a highly active inflammatory response. Moreover, stronger MMP expression is associated with higher activity index and a more profound renal dysfunction.

Nonsecretory multiple myeloma - a rare case of acute renal failure

Multiple myeloma (MM) is a plasma cell dyscrasia accounting for 10% of all hematologic malignancies. Diagnosis is based on histologic, serologic and radiographic features. The nephrotoxic manifestations of immunoglobulin light chain overproduction are the most common cause of renal function impairment. The most frequent renal lesion is "cast nephropathy" and results from immunoglobulin light chain nephrotoxicity. MM very rarely produces diffuse bilateral renal infiltration. We report the interesting case of a patient with non-secretory myeloma, who presented with acute renal failure and increased kidney size due to massive renal infiltration by plasma cells. Pulse steroid therapy lead to rapid renal function improvement and reduction in kidney size. Renal failure is a frequent manifestation of MM, which can affect kidneys in several ways. MM should be included in the differential diagnosis of every case of unexplained renal failure, especially in the elderly, even in the absence of an M spike in serum and urine electrophoresis.

Regression of massive tumoral calcinosis of the ischium in a dialysis patient after treatment with reduced calcium dialysate and i.v. administration

BACKGROUND

Tumoral calcinosis, an inherited metabolic disorder, has been described with increasing frequency over the last 20 years [Drueke 1966]. It is characterized by massive calcium phosphate deposits in periarticular tissues, usually around large joints, especially the hips, knees and elbows (editorial in Lancet 1987).

PATIENT AND METHOD

We describe a 58-year-old male patient with tumoral calcinosis of the ischium and severe hyperparathyroid bone disease, successfully treated with reduced calcium dialysate and vitamin D.

CONCLUSION

We believe that in cases of tumoral calcification with histologically proven hyperparathyroid bone disease, lowering the calcium dialysate concentration together with careful administration of vitamin analogs and monitoring of serum calcium, phosphate and parathyroid hormone levels, may be the ideal therapeutic approach. Control of hyperphosphatemia would be best achieved with measures other than administration of aluminium phosphate binders if one wishes to avoid the induction of adynamic bone.