COVID-19 and kidney: role of SARS-CoV-2 infection in the induction of renal damage.

OBJECTIVE: SARS-CoV-2 causes acute respiratory disease, interstitial and alveolar pneumonia, and involves numerous organs and systems such as the kidney, heart, digestive tract, blood, and nervous system. We aimed to evaluate the incidence of renal manifestations in patients diagnosed with COVID-19 infection. PATIENTS AND METHODS: We performed a monocentric, cross-sectional, observational study, conducted on 114 patients with SARS-CoV-2. Clinical and laboratory parameters [renal function, serum electrolytes, inflammatory state, blood gas analysis, Interleukin 6 (IL-6) and urinalysis] were evaluated. The same values were checked out after two months (T1), however after negativization. RESULTS: We enrolled 114 patients (59 males) with a mean age of 63.8 ± 13.9 years. We found hematuria in 48 patients (55.8%), proteinuria in 33 patients (38.4%), leukocyturia in 61 patients (70.9%), acute kidney injury (AKI) in 28 patients (24.6%), AKI in chronic kidney disease (CKD) in 24 patients (21.1%). Moreover, we found a significant increase of inflammatory indexes as C Reactive Protein (CRP), lactic dehydrogenase (LDH), alpha 1 and alpha 2 globulins with a subsequent reduction at T1 (p = 0.016, p < 0.001, p = 0.005, p = 0.007; respectively). Hemoglobin and erythrocyte values significantly decreased (p < 0.001, p = 0.003, respectively), and we found lymphopenia (p < 0.001). Also, we found elevated levels of the D-Dimer (p < 0.001) and a significant increase in the International Normalized Ratio (INR) (p = 0.038). We also showed a significant improvement after negativization in oxygen partial pressure (p = 0.001) and oxygen saturation (p < 0.001) and a significant increase in pH (p = 0.018) and bicarbonate concentration (p = 0.042). Moreover, we found a significant increase in IL-6 (p = 0.004). Also, we reported mild hyponatremia and hypokalemia with subsequent significant recovery (p < 0.001, p < 0.001, respectively) and mild hypochloremia with a recovery to the limits of statistical significance (p = 0.053). At the entrance, we found an increase in serum glucose with a significant reduction during recovery (p < 0.001). CONCLUSIONS: The prevalence of AKI and/or CKD and/or abnormal urinalysis in patients diagnosed with COVID-19 on admission seems to be high and appears as a negative prognostic factor. Urinalysis appears to be very useful in unveiling the potential kidney impairment of COVID-19 patients; therefore, urinalysis could be used to reflect and predict the disease severity. We also recommend a careful evaluation of metabolic alterations, inflammatory states, and electrolytic disorders in COVID-19 patients.

Male reproductive health after 3 months from SARS-CoV-2 infection: a multicentric study.

PURPOSE: While SARS-CoV-2 infection appears not to be clinically evident in the testes, indirect inflammatory effects and fever may impair testicular function. To date, few long-term data of semen parameters impairment after recovery and comprehensive andrological evaluation of recovered patients has been published. The purpose of this study was to investigate whether SARS-CoV-2 infection affect male reproductive health. METHODS: Eighty patients were recruited three months after COVID-19 recovery. They performed physical examination, testicular ultrasound, semen analysis, sperm DNA integrity evaluation (TUNEL), anti-sperm antibodies (ASA) testing, sex hormone profile evaluation (Total testosterone, LH, FSH). In addition, all patients were administered International Index of Erectile Function questionnaire (IIEF-15). Sperm parameters were compared with two age-matched healthy pre-COVID-19 control groups of normozoospermic (CTR1) and primary infertile (CTR2) subjects. RESULTS: Median values of semen parameters from recovered SARS-CoV-2 subjects were within WHO 2010 fifth percentile. Mean percentage of sperm DNA fragmentation (%SDF) was 14.1 ± 7.0%. Gelatin Agglutination Test (GAT) was positive in 3.9% of blood serum samples, but no positive semen plasma sample was found. Only five subjects (6.2%) had total testosterone levels below the laboratory reference range. Mean bilateral testicular volume was 31.5 ± 9.6 ml. Erectile dysfunction was detected in 30% of subjects. CONCLUSION: Our data remark that COVID-19 does not seem to cause direct damage to the testicular function, while indirect damage appears to be transient. It is possible to counsel infertile couples to postpone the research of parenthood or ART procedures around three months after recovery from the infection.

In vitro evaluation of different antimicrobial combinations against carbapenemase-producing Klebsiella pneumoniae: the activity of the double-carbapenem regimen is related to meropenem MIC value.

Objectives and methods: We evaluated the in vitro activity of different antimicrobial combinations with and without colistin against 39 carbapenem-resistant Klebsiella pneumoniae (CR-Kp) strains (colistin + meropenem/doripenem, colistin + tigecycline, colistin + rifampicin, gentamicin + meropenem, gentamicin + tigecycline and the double-carbapenem regimen meropenem + ertapenem) using the chequerboard method. The triple combination colistin + meropenem + tigecycline was also tested. In addition, killing studies were performed for meropenem + ertapenem. Results: Gentamicin-based combinations showed a high level of synergy. Meropenem + ertapenem was synergic in 12/39 (30.7%) of the strains, whereas based on killing studies 1 × MIC meropenem + 1 × MIC ertapenem and 2 × MIC meropenem + 1 × MIC ertapenem combinations were bactericidal and synergic at 24 h [mean area under the bactericidal curve (AUBC) 54.9 ±âŸ26.1 and 44.2 ±âŸ15.3 compared with 1 × MIC meropenem (134.5 ±âŸ40.1) and 2 × MIC meropenem (126.4 ±âŸ5.4), respectively, P < 0.0001]. When the results were stratified according to meropenem MIC, we found that the degree of synergy significantly increased for isolates with lower meropenem (and not ertapenem) MICs, up to an MIC of 128 mg/L. Among colistin-containing combinations, synergy was observed in 18/39 (46.1%), 33/34 (97%), 24/39 (61.5%) and 17/39 (43.5%) of the strains for colistin + meropenem, colistin + rifampicin, colistin + tigecycline and colistin + doripenem, respectively, including colistin-resistant strains. Colistin + meropenem + tigecycline at subinhibitory concentrations resulted in the absence of growth of 37/39 strains (94.8%). Conclusions: Our in vitro data suggest that colistin might be a valid therapeutic option against CR-Kp, even in the presence of colistin resistance, whereas the double-carbapenem regimen represents a viable option when colistin is not recommended, especially if the meropenem MIC is ≤ 128 mg/L. Since traditional antimicrobial susceptibility reports are not sufficiently informative for clinicians, synergy testing as well as actual meropenem MIC evaluation should always be performed in the case of CR-Kp infections.

Polyomavirus BK infection in pediatric kidney-allograft recipients: a single-center analysis of incidence, risk factors, and novel therapeutic approaches.

BACKGROUND: Although a growing body of literature regarding polyoma BK virus (BKV) infection and associated interstitial nephritis in kidney-allograft recipients is becoming available, the impact of BKV infection in the pediatric population has not been fully evaluated. METHODS: In a retrospective analysis, we performed polymerase chain reaction (PCR) assays for BKV DNA in serum and urine samples from 100 pediatric kidney-allograft recipients referred to our institution in the last 5 years. RESULTS: BKV viruria was observed in 26 of 100 patients, whereas BKV viremia was demonstrated in 5 patients. Serum creatinine was significantly higher in recipients with positive BK viremia compared with BKV DNA-negative patients (mean 2.66 vs. 1.14 mg/100 mL). Renal biopsy performed in 3 of 5 patients showed graft damage consistent with interstitial nephropathy. In the univariate analysis, negative antibody status of the recipient and the presence of mycophenolate mofetil in baseline immunosuppression were the two factors predictive of active BKV infection. CONCLUSIONS: Our study shows that BKV-associated nephropathy is a relevant complication in the pediatric kidney transplantation setting also. Identification of patients at risk of developing virus-associated nephropathy, through prospective quantification of viral load, could improve clinical outcome by allowing the use of timely preemptive therapy guided by BKV DNA levels.

Clinical and molecular heterogeneity of juvenile nephronophthisis in Italy: insights from molecular screening.

Autosomal recessive nephronophthisis (NPH) is a renal disorder histologically characterized by tubulointerstitial lesions that are, in some cases, associated with extrarenal manifestations such as tapeto-retinal degeneration or liver fibrosis. The disease is usually pauci-symptomatic in an early phase but invariably evolves to end-stage renal failure in childhood or early adulthood. The recent discovery of the NPHP1 gene (nephrocystin) has prompted research into putative genotype-phenotype correlations. We screened a population of 68 Italian children (10 multiplex families, 47 sporadic cases) with a clinical and histopathologic picture of NPH and found a large homozygous deletion at 2q13 involving nephrocystin in 30 cases, and heterozygous deletion associated with new point mutations at exons 15 (Tyr518Ter) and 17 (Arg585Ter) of the gene in two other cases. The remaining 36 children had no apparent molecular defects of nephrocystin. In spite of this genetic heterogeneity, the two groups, with and without detectable molecular defects of nephrocystin, showed similar renal defects and comparable cumulative survival considering the start of dialysis as an end-point. The unique difference observed was a less frequent requirement of dialysis in NPH1 patients with pure renal form. Finally, tapeto-retinal degeneration was associated with renal lesions in seven cases presenting deletion of the nephrocystin gene and in five sporadic cases without molecular defects. These data show that a molecular defect of nephrocystin is involved in approximately 50% of patients with NPH, and another 50% require further molecular characterization. Research therefore should now be aimed at characterizing a new locus. In spite of the molecular heterogeneity, NPH in children presents similar renal and extrarenal manifestations, thus suggesting the involvement of common pathological routes.

Urinary excretion of brush border antigens and other proteins in children with vesico-ureteric reflux.

This study was designed to evaluate the occurrence and the type of proteinuria in 82 children with vesico-ureteric reflux (VUR) with or without renal scars. The urinary excretion of the high molecular weight protein albumin was taken as an index of glomerular alterations and the excretion of retinol-binding protein (RBP), beta 2-microglobulin and brush border antigens (BBA) (measured by monoclonal antibody-based enzyme-linked immunosorbent assay) was taken as an index of tubular alterations. All such markers were increased in children with VUR and were related to the degree of renal function. Patients showing reduced creatinine clearance had very high levels of albuminuria, microproteinuria and BBA, with all these variables reciprocally correlated. In children with normal renal function however, only microproteins (not albumin or BBA) were slightly increased, thus indicating an isolated tubular defect without involvement of the proximal segment of the tubule. However, microprotein excretion did not correlate with the grade of scarring (99mtechnetium-dimercaptosuccinic acid scan), both RBP and beta 2-microglobulin excretion being normal in 75% of children with radioisotopic signs of renal lesions but increased in 17% of children without scars. Therefore, tubular proteinuria identifies different groups of children with VUR but is not related to renal scarring. Prospective studies will define the usefulness of proteinuria as a reliable indicator of renal outcome.

Tubular epithelium culture from nephronophthisis-affected kidneys: a new approach to molecular disorders of tubular cells.

Abnormalities of tubular membrane structure and composition have been proposed as the primary defect in nephronophthisis (NEF). In order to characterize the protein composition of tubular cells in NEF, in vitro methods were developed to culture and propagate tubular cells obtained from biopsy fragments. Accordingly, microdissected cortical slices (1 x 3 mm) were first digested with collagenase and DNAse and then grown in RPMI medium supplemented with 10% NU serum and conditioned serum deriving from 3T3 cultures. At confluence, cultured cells from NEF showed characteristics which were typical of normal tubules, i.e. presence of cytokeratin and positivity for succinic dehydrogenase and alkaline phosphatase stainings, and presented no morphological alterations compared to cultured cells from normal tubular epithelium. Moreover, no difference was observed for fibronectin, collagen IV and laminin stains. Analysis by two-dimensional electrophoresis of cellular extracts revealed several changes in protein composition of NEF, the main one being the decrease in NEF cells of a polypeptide with a molecular weight of 120 kD and a pI of 4.8; this polypeptide was a constant finding in normal kidneys. These observations demonstrated that human tubular epithelial cells can be successfully cultured from very small biopsy fragments, which represents a new approach to the study of molecular disorders involving tubular cells in inherited disease. Cultured cells from NEF maintain the same morphological, immunological and cytochemical characteristics as normal tubular cells, but present a few alterations in polypeptide composition which may have pathogenetic relevance. A more careful analysis of these alterations is needed to define the molecular disorder(s) involving the tubule in NEF.

Continuous ambulatory peritoneal dialysis (CAPD) of children with amino acid solutions: technical and metabolic aspects.

The changes in plasma and dialysate amino acids (AA) in 7 continuous ambulatory peritoneal dialysis (CAPD) children after dialysis with a 1% AA solution were compared with a glucose-containing solution. During the AA-exchange, the plasma levels of individual AA reached their peaks after 1 h, with their percentage increments significantly correlated (p less than 0.001) with the ratio of the amount of AA in the bag to the basal plasma concentration. The plasma concentration of methionine, valine, phenylalanine, and isoleucine remained higher than the basal value at 4 h. The amount of AA absorbed was 66% after 1 h, and 86% after 4 h and 6 h, corresponding to 2574 +/- 253 mumol/kg body wt. During glucose-dialysis (1.36%), levels of histidine, methionine, valine, phenylalanine, and isoleucine were significantly decreased in plasma after 1 h, and stayed low throughout the dialysis period. The loss of AA with the peritoneal effluent was 116 +/- 69 mumol/kg/body wt. From this study, it seems that using an AA dialysis solution, with 1 exchange per day, might limit the daily glucose load and compensate for AA losses by supplying an extra amount of AA and by reducing the loss of other AA not contained in dialysis solutions. The AA pattern in plasma following AA-dialysis resembles that observed after a protein meal, with no signs of persistently high, nonphysiological levels.

The branchio-oto-renal syndrome (report of two family groups).

The major features of the Branchio-Oto-Renal syndrome (BOR syndrome), an autosomal dominant disorder, are branchial remnants, ear anomalies, deafness and renal dysplasia. We report two family groups affected by the BOR syndrome: in two-thirds of the affected children renal abnormalities led to severe renal insufficiency in early life. The necessity for a meticulous search for renal anomalies in individuals with aural and/or branchial abnormalities is emphasized. In affected families, genetic counselling is suggested.

Renal selectivity properties towards endogenous albumin in minimal change nephropathy.

It is well accepted that the molecular charge and conformation of serum proteins are major determinants of their glomerular filtration, but few studies characterizing the molecular features of circulating proteins in renal diseases are currently available. In 11 children affected by minimal change nephropathy (MCN) we determined the electrical charge and the fluorescence quantum yield of Tyrosine (Tyr) and Tryptophan (Trp) (taken as index of conformation) of serum and urinary albumin before and after steroid-induced remission of proteinuria. In all proteinuric children at the onset of the disease, urinary albumin was formed by one band with an isoelectric point (pI) of 4.7 (pI of the native protein), and by numerous other, less anionic bands with pIs between 4.8 and 5.5 accounting for about 50% of the total amount of this protein. The normalization of proteinuria which followed steroid therapy was characterized by the disappearance in urines of the less anionic fraction and by the appearance of numerous isoforms with a pI still more anionic (pI less than 4.7) than normal. At the same time, in the proteinuric phase, the fluorescence quantum yield of Trp of urinary albumin was markedly quenched, returning to near normal levels after steroid-induced remission of proteinuria. These data indicate that in MCN the charge-dependent renal selectivity properties are partially maintained and that the less anionic isoforms of albumin are a main component of urinary albumin. Together with the electrical charge, the conformation of albumin as a major determinant of its urinary excretion in MCN must also be considered.