Abnormal Development of Microbiota May Be a Risk Factor for Febrile Urinary Tract Infection in Infancy

Febrile urinary tract infection (fUTI) is common in infants, but specific risk factors for developing it remain unclear. As most fUTIs are caused by ascending infections of intestinal bacteria, dysbiosis-an imbalance in gut microbial communities-may increase fUTI risk. This study was conducted to test the hypothesis that abnormal development of gut microbiota during infancy increases the risk of developing fUTI. Stool samples were collected from 28 infants aged 3-11 months with first-onset fUTI (fUTI group) and 51 healthy infants of the same age (HC group). After bacterial DNA extraction, 16S rRNA expression was measured and the diversity of gut microbiota and constituent bacteria were compared between the two groups. The alpha diversity of gut microbiota (median Shannon index and Chao index) was significantly lower in the fUTI group (3.0 and 42.5) than in the HC group (3.7 and 97.0; p < 0.001). The beta diversity also formed different clusters between the two groups (p < 0.001), suggesting differences in their microbial composition. The linear discriminant analysis effect size showed that the fUTI group proportionally featured significantly more Escherichia-Shigella in the gut microbiota (9.5%) than the HC group (3.1%; p < 0.001). In summary, abnormal gut microbiota development during infancy may increase the risk of fUTI.

Accuracy of diagnosing acute kidney injury by assessing urine output within the first week of life in extremely preterm infants

BACKGROUND

Neonatal acute kidney injury (AKI) is associated with increased mortality and is often assessed with the neonatal modified Kidney Disease: improving Global Outcomes (KDIGO) classification, which uses changes in serum creatinine levels. However, because this classification has many drawbacks, a novel method, the neonatal Risk, Injury, Failure, Loss, and End-Stage Kidney Disease (nRIFLE) classification for diagnosing neonatal AKI according to urine output (UO), was recently proposed. To date, no data on the incidence of AKI according to nRIFLE are available for extremely preterm infants (born at gestational age less than 28 weeks). This study was conducted to clarify the association between incidence of AKI and in-hospital mortality in extremely preterm infants.

METHODS

Of 171 extremely preterm infants hospitalized from 2006 to 2020, 84 in whom indwelling bladder catheters were placed for UO measurements within 24 h of life were included. The incidence of AKI was assessed using the nRIFLE classification. In-hospital mortality was compared between patients with AKI and those without it.

RESULTS

The incidence of AKI during the first week of life was 56% and that of in-hospital mortality was significantly higher in patients with AKI (25.5%) than in those without it (2.8%). The odds ratio was 12.3 with 95% confidence interval ranging from 1.5 to 100.0.

CONCLUSION

The incidence of AKI according to nRIFLE was higher than reported in most previous studies using the neonatal modified KDIGO classification, suggesting that assessment by nRIFLE criteria using UO may improve diagnostic accuracy of AKI in extremely preterm infants.

Association of Neonatal Jaundice with Gut Dysbiosis Characterized by Decreased Bifidobacteriales

Neonatal jaundice, caused by excess serum bilirubin levels, is a common condition in neonates. Imbalance in the gut microbiota is believed to play a role in the development of neonatal jaundice. Thus, we aimed to reveal the gut microbiota characteristics in neonates with jaundice. 16S rRNA gene sequencing was performed on stool samples collected on day 4 from 26 neonates with jaundice (serum total bilirubin > 15.0 mg/dL) and 17 neonates without jaundice (total serum bilirubin < 10.0 mg/dL). All neonates were born full term, with normal weight, by vaginal delivery, and were breastfed. Neonates who were administered antibiotics, had serum direct bilirubin levels above 1 mg/dL, or had conditions possibly leading to hemolytic anemia were excluded. The median serum bilirubin was 16.0 mg/dL (interquartile range: 15.5-16.8) and 7.4 mg/dL (interquartile range: 6.8-8.3) for the jaundice and non-jaundice groups, respectively. There was no difference in the alpha diversity indices. Meanwhile, in the jaundice group, linear discriminant analysis effect size revealed that Bifidobacteriales were decreased at the order level, while Enterococcaceae were increased and Bifidobacteriaceae were decreased at the family level. Bifidobacteriaceae may act preventatively because of their suppressive effect on beta-glucuronidase, leading to accelerated deconjugation of conjugated bilirubin in the intestine. In summary, neonates with jaundice had dysbiosis characterized by a decreased abundance of Bifidobacteriales.

Idiopathic nephrotic syndrome in children: role of regulatory T cells and gut microbiota

BACKGROUND

We investigated whether an association exists between regulatory T cells (Tregs) during initial presentation in children with idiopathic nephrotic syndrome (INS) and later development of frequently relapsing INS.

METHODS

Blood samples were obtained at onset and at remission from 25 patients (median age, 4.0 years) with INS; eight did not show relapse after initial response (non-relapsing [NR]), whereas 17 showed frequent relapses (frequently relapsing [FR]). Tregs were measured by flow cytometry; increases were compared between groups. Fecal samples were obtained at onset from 20 patients with INS, as well as from 20 age-matched healthy children. Gut microbiota composition was assessed using 16S ribosomal RNA (rRNA) sequencing (ion PGM).

RESULTS

The rate of increase in Tregs from onset to remission was significantly lower in the FR group (124.78%) than in the NR group (879.16%; P < 0.001). Additionally, 16S rRNA sequencing of gut microbiota showed that the proportion of butyric acid-producing bacteria was significantly lower in the FR group (7.08%) than in the healthy children (17.45%; P < 0.001).

CONCLUSIONS

In children with INS, small increases in Tregs in response to steroid treatment were associated with subsequent increased risk of frequent relapses. In addition, the FR group had a greater degree of dysbiosis at onset.

IMPACT

A low rate of Tregs increase is associated with subsequent frequent relapses of INS. The increase in Tregs in response to steroid treatment was small when dysbiosis was present in patients with INS, particularly when the proportion of butyrate-producing bacteria was considerably reduced We presume that improvement of dysbiosis by administration of probiotics and prebiotics may enhance the rate of Tregs' increase, thus preventing frequent relapse.

Clinical Significance of Probiotics for Children with Idiopathic Nephrotic Syndrome

We previously reported that a decrease in butyrate-producing bacteria in the gut is a potential cause of regulatory T cell (Treg) abnormalities in children with idiopathic nephrotic syndrome (INS). Therefore, we hypothesized that administration of butyrate-producing bacteria might reduce INS relapse and the need for immunosuppressants in these patients. Twenty patients in remission from INS (median age 5.3 years, 15 boys) were enrolled in the study and assigned to receive either daily oral treatment with a preparation of 3 g Clostridium butyricum or no probiotic treatment. The number of relapses and requirement for immunosuppressive agents were compared between the two groups. In the probiotic treatment group, analyses of the gut microbiota and Treg measurements were also performed. Probiotic-treated patients experienced fewer INS relapses per year compared with non-probiotic-treated patients (p = 0.016). Further, administration of rituximab in the probiotic treatment group was significantly less frequent compared with the non-probiotic-treated group (p = 0.025). In the probiotic treatment group, analyses before and after probiotic treatment revealed the significant increases in the relative abundance of butyrate-producing bacteria (p = 0.017) and blood Treg counts (p = 0.0065). Thus, oral administration of butyrate-producing bacteria during INS remission may reduce the frequency of relapse and the need for immunosuppressive agents.

Nephrotic syndrome-associated hypercoagulopathy is alleviated by both pioglitazone and glucocorticoid which target two different nuclear receptors

BACKGROUND

Thrombosis is a potentially life-threatening nephrotic syndrome (NS) complication. We have previously demonstrated that hypercoagulopathy is proportional to NS severity in rat models and that pioglitazone (Pio) reduces proteinuria both independently and in combination with methylprednisolone (MP), a glucocorticoid (GC). However, the effect of these treatments on NS-associated hypercoagulopathy remains unknown. We thus sought to determine the ability of Pio and GC to alleviate NS-associated hypercoagulopathy.

METHODS

Puromycin aminonucleoside-induced rat NS was treated with sham, Low- or High-dose MP, Pio, or combination (Pio + Low-MP) and plasma was collected at day 11. Plasma samples were collected from children with steroid-sensitive NS (SSNS) and steroid-resistant NS (SRNS) upon presentation and after 7 weeks of GC therapy. Plasma endogenous thrombin potential (ETP), antithrombin (AT) activity, and albumin (Alb) were measured using thrombin generation, amidolytic, and colorimetric assays, respectively.

RESULTS

In a rat model of NS, both High-MP and Pio improved proteinuria and corrected hypoalbuminemia, ETP and AT activity (p < .05). Proteinuria (p = .005) and hypoalbuminemia (p < .001) were correlated with ETP. In childhood NS, while ETP was not different at presentation, GC therapy improved proteinuria, hypoalbuminemia, and ETP in children with SSNS (p < .001) but not SRNS (p = .330).

CONCLUSIONS

Both Pio and GC diminish proteinuria and significantly alleviate hypercoagulopathy. Both Pio and MP improved hypercoagulopathy in rats, and successful GC therapy (SSNS) also improved hypercoagulopathy in childhood NS. These data suggest that even a partial reduction in proteinuria may reduce NS-associated thrombotic risk.

High daily salt intake had a negative impact on how well nocturnal enuresis treatment worked on children aged 7-10 years

AIM

We investigated whether the daily salt intake of children with nocturnal enuresis influenced their response to 1-desamino-8-D-arginine vasopressin therapy.

METHODS

This study comprised 129 children (67.4% boys) with a median age of 9.2 years (range 7.2-10.4) with monosymptomatic nocturnal enuresis who were seen at Kansai Medical University Hospital, Osaka, Japan, from 2013 to 2017. Urinary sodium concentrations were determined using a spot urine test, and the children were divided into appropriate (n = 55) and excessive salt intake (n = 74) groups based on Japanese Government guidelines. After a month of therapy, the treatment responses were compared for 39 and 50 children, respectively.

RESULTS

There were no significant differences in the urea nitrogen-to-creatinine or calcium-to-creatinine ratios in the two groups. However, the excessive salt intake group showed a significantly reduced treatment response to the appropriate salt intake group. In addition, the excessive and appropriate salt intake groups showed median efficacy ratios of 8.2% and 21.8%, respectively, based on intention-to-treat analysis (P = 0.029) and 12.0% and 30.8% based on per-protocol analysis (P = 0.029).

CONCLUSION

High daily salt intake significantly reduced the efficacy of ddavp therapy for nocturnal enuresis and consumption should be controlled during treatment.

Predicting and Defining Steroid Resistance in Pediatric Nephrotic Syndrome Using Plasma Proteomics

INTRODUCTION

Nephrotic syndrome (NS) is a characterized by massive proteinuria, edema, hypoalbuminemia, and dyslipidemia. Glucocorticoids (GCs), the primary therapy for >60 years, are ineffective in approximately 50% of adults and approximately 20% of children. Unfortunately, there are no validated biomarkers able to predict steroid-resistant NS (SRNS) or to define the pathways regulating SRNS.

METHODS

We performed proteomic analyses on paired pediatric NS patient plasma samples obtained both at disease presentation before glucocorticoid initiation and after approximately 7 weeks of GC therapy to identify candidate biomarkers able to either predict steroid resistance before treatment or define critical molecular pathways/targets regulating steroid resistance.

RESULTS

Proteomic analyses of 15 paired NS patient samples identified 215 prevalent proteins, including 13 candidate biomarkers that predicted SRNS before GC treatment, and 66 candidate biomarkers that mechanistically differentiated steroid-sensitive NS (SSNS) from SRNS. Ingenuity Pathway Analyses and protein networking pathways approaches further identified proteins and pathways associated with SRNS. Validation using 37 NS patient samples (24 SSNS/13 SRNS) confirmed vitamin D binding protein (VDB) and APOL1 as strong predictive candidate biomarkers for SRNS, and VDB, hemopexin (HPX), adiponectin (ADIPOQ), sex hormone-binding globulin (SHBG), and APOL1 as strong candidate biomarkers to mechanistically distinguish SRNS from SSNS. Logistic regression analysis identified a candidate biomarker panel (VDB, ADIPOQ, and matrix metalloproteinase 2 [MMP-2]) with significant ability to predict SRNS at disease presentation (P = 0.003; area under the receiver operating characteristic curve = 0.78).

CONCLUSION

Plasma proteomic analyses and immunoblotting of serial samples in childhood NS identified a candidate biomarker panel able to predict SRNS at disease presentation, as well as candidate molecular targets/pathways associated with clinical steroid resistance.

SAT-157 A Calcium-deficient Diet In Dams During Gestation Increases Insulin Resistance In Male Offspring

Backgrounds: Maternal malnutrition and the resulting low birth weight predispose offspring to various diseases, including adult-onset insulin resistance syndrome. Several lines of evidence demonstrate that calcium (Ca) plays an important role in the pathogenesis of insulin resistance syndrome and obesity, suggesting that hypocalcemia is a risk factor for developing these conditions. We previously reported that maternal Ca deficiency during pregnancy can affect regulation of non-imprinted genes by altering epigenetic regulation of gene expression, thereby inducing different metabolic phenotypes. On the other hand, osteocalcin (OC), a bone formation biomarker, acts directly on β-cells to increase their mass and proliferation and, therefore, increases insulin secretion. Aims: We studied whether alterations in insulin resistance and secretion were induced in offspring by feeding dams a Ca-deficient diet during pregnancy and lactation, and to explore the association between bone and glucose metabolism. Methods: Female Wistar rats consumed either a Ca-deficient (0.008% Ca) or control (0.90% Ca) diet ad libitum from 3 weeks preconception to 21 days postparturition. Pups were allowed to nurse their original mothers until weaning. The offspring were fed a control diet beginning at weaning (day 21) and were killed on day 180 ± 10. Serum carboxylated OC (Gla-OC) and undercarboxylated OC (Glu-OC), insulin and adipokines in offspring were measured using enzyme-linked immunosorbent assay kits. Ionized calcium (iCa) and magnesium (iMg) were measured by ion-selective electrodes. Results: In males, mean levels of insulin, glucose, and Homeostasis Model Assessment of Insulin Resistance were higher in the Ca-deficient group than in the control group. Mean adiponectin levels and iMg in Ca-deficient male offspring were higher than those in control male offspring. The serum ionized Ca/Mg ratio in Ca-deficient male offspring was lower than that in control male offspring. In addition, iCa was inversely associated with serum Glu-OC and adiponectin in males. In females, mean levels of Glu-OC and Gla-OC in the Ca-deficient group were higher than in the control group, whereas no significant difference was observed in these measures between the two groups in male offspring. In all offspring, serum leptin levels were correlated with iMg (p=0.0039, R=0.436) and serum insulin levels (p<0.0001, R=0.62), and inversely correlated with iCa (p=0.0025, R=-0.454). Conclusion: Maternal Ca restriction during pregnancy alters postnatal growth and insulin resistance in a sex- and window of exposure-specific manner. Increased Glu-OC may mitigate insulin resistance in female Ca-deficient offspring. The present study provided further support for the hypothesis that early postnatal lactation plays a sexually divergent role in programming the phenotype later in life.

A Calcium-Deficient Diet in Dams during Gestation Increases Insulin Resistance in Male Offspring

Calcium (Ca) plays an important role in the pathogenesis of insulin resistance syndrome. Osteocalcin (OC), a bone formation biomarker, acts directly on β-cells and increases insulin secretion. We determined the effects of Ca deficiency during pregnancy and/or lactation on insulin resistance in offspring. Female Wistar rats consumed either a Ca-deficient or control diet ad libitum from three weeks preconception to 21 days postparturition. Pups were allowed to nurse their original mothers until weaning. The offspring were fed a control diet beginning at weaning and were killed on day 180. Serum carboxylated OC (Gla-OC) and undercarboxylated OC (Glu-OC), insulin and adipokines in offspring were measured. In males, mean levels of insulin, glucose, and HOMA-IR were higher in the Ca-deficient group than in the control group. In addition, ionized Ca (iCa) was inversely associated with serum Glu-OC and adiponectin in males. In females, mean levels of Glu-OC and Gla-OC in the Ca-deficient group were higher than in the control group. In all offspring, serum leptin levels were correlated with serum insulin levels, and inversely correlated with iCa. In conclusion, maternal Ca restriction during pregnancy and/or lactation influences postnatal offspring Ca metabolism and insulin resistance in a sex-specific manner.

Antiproteinuric effect of an endothelin-1 receptor antagonist in puromycin aminonucleoside-induced nephrosis in rat

BackgroundThe pathogenesis of idiopathic nephrotic syndrome (INS) remains unclear, although recent studies suggest endothelin 1 (ET-1) and CD80 of podocytes are involved. We investigated the potential of antagonist to ET-1 receptor type A (ETRA) as therapeutic agent through the suppression of CD80 in a rat model of INS.MethodsPuromycin aminonucleoside (PAN) was injected to Wister rats to induce proteinuria: some were treated with ETRA antagonist and others were treated with 0.5% methylcellulose. Blood and tissue samples were collected. Quantitative PCR was used to determine the expression of Toll-like receptor-3 (TLR-3), nuclear factor-κB (NF-κB), CD80, talin, ETRA, and ET-1 in the kidney. To confirm the level of CD80 protein expression, immunofluorescence staining and western blot analysis of the renal tissue were performed.ResultsAmount of proteinuria in the treatment group was significantly lower than the other groups. The same-day body weight, serum creatinine values, and blood pressure were not significantly different. ETRA antagonist restores podocyte foot process effacement as well as the aberrant expression of TLR-3, nuclear factor-κB (NF-κB), and CD80 in PAN-injured kidneys.ConclusionsThe ETRA antagonist may be promising drug for INS as it showed an antiproteinuric effect. Its action was considered to be through suppression of CD80 expression on podocytes.

Gut Microbiota Dysbiosis in Children with Relapsing Idiopathic Nephrotic Syndrome

BACKGROUND

While the etiology of idiopathic nephrotic syndrome (idiopathic nephrotic syndrome [INS]; characterized by repeated relapses and comorbid allergic conditions) remains unknown, recent evidence suggests that dysfunction in regulatory T cells (Tregs) plays an important role in the development of INS as well as allergic diseases. We hypothesized that dysbiosis involving decreased butyric acid-producing gut microbiota leads to defective induction and differentiation of peripherally induced Tregs, resulting in INS relapse.

METHODS

Study subjects were 12 children with INS, 8 classified as relapsing (R group; median age: 3.0 years) and 4 as non-relapsing (NR group; median age: 4.3 years), and 11 healthy children (HC group; median age: 5.1 years) serving as normal controls. Measurement of microbiota was performed using 16S ribosomal RNA metagenomic analysis, and fecal butyric acid was measured using high performance liquid chromatography. Flow-cytometric analysis of Tregs and CD4-positive (CD4+) cells in peripheral blood was also performed.

RESULTS

Metagenomic analysis of gut microbiota using feces showed that the proportion of butyric acid-producing bacteria was significantly lower in R (median 6.36%) than HC (median 18.84%; p = 0.0013), but no different between NR (median 16.71%) and HC (p = 0.29). Fecal organic acid analysis revealed significantly lower butyric acid quantities in R than HC (medians: 0.48 vs. 0.99 mg/g, p = 0.042). Circulating Tregs as a proportion of CD4+ cells were decreased in 75% of R and NR.

CONCLUSION

Pediatric relapsing INS patients show gut microbiota dysbiosis, characterized by a decreased proportion of butyric acid-producing bacteria and lower fecal butyric acid quantities, concomitant with reduced circulatory Tregs.

Urinary C-megalin for screening of renal scarring in children after febrile urinary tract infection

BackgroundFebrile urinary tract infection (fUTI) in children may cause renal scarring. This study aimed to investigate the usefulness of urinary biomarkers for diagnosing renal scarring after fUTI.MethodsThirty-seven children (median age: 1.36 years, range: 0.52-12.17 years, 25 boys) with a history of fUTI, who underwent renal scintigraphy for 4 months or longer after the last episode of fUTI, were analyzed. A spot urine sample was obtained on the day of renal scintigraphy to measure levels of total protein, N-acetyl-β-D-glucosaminidase (NAG), β₂-microglobulin (BMG), neutrophil gelatinase-associated lipocalin (NGAL), liver-type fatty acid binding protein (L-FABP), and C-megalin (full-length megalin). Results were corrected for urinary creatinine (Cr) and compared between the group with renal scarring (n=23) and that without scarring (n=14). Urinary levels of C-megalin were also measured in healthy control subjects.ResultsNo significant differences in total protein, NGAL, L-FABP, NAG, and BMG levels were found between the groups. However, C-megalin levels were significantly higher in the renal scarring group than in the non-renal scarring group and healthy controls (P<0.001). A cutoff value of 6.5 pmol/nmol of urinary C-megalin/Cr yielded 73.9% of specificity and 92.9% of sensitivity.ConclusionUrinary C-megalin is useful for diagnosing renal scarring caused by fUTI.

Effect of cesarean section on relapse of childhood idiopathic nephrotic syndrome

In parallel with the increase in the prevalence of childhood chronic diseases, the rate of cesarean delivery has risen during the past decades. This study tested the hypothesis that children delivered by cesarean section (CS) have a higher risk of relapse of idiopathic nephrotic syndrome (INS). Fifty-six children with INS were categorized into three groups. Group A consisted of patients with INS who had no relapses after the onset of INS; group B consisted of patients with INS who had infrequent relapse; and group C consisted of patients with INS who had frequent relapse. The number of enrolled patients in groups A, B, and C was 10, 14, and 32, respectively. The ratio of neonates delivered via CS was significantly higher in group C (37.5%, P < 0.001) than in groups A (0%) and B (7.1%). This study shows that CS is associated with an increased risk of relapse of childhood INS.

Nephron development and extrarenal features in a child with congenital nephrotic syndrome caused by null LAMB2 mutations

BACKGROUND

Congenital nephrotic syndrome (CNS) is a rare disorder caused by various structural and developmental defects of glomeruli. It occurs typically as an isolated kidney disorder but associates sometimes with other systemic, extrarenal manifestations.

CASE PRESENTATIONS

An infant presented with severe CNS, which progressed rapidly to renal failure at age of 3 months and death at 27 months. The clinical phenotypes and genetic causes were studied, including the renal pathology at autopsy. Besides the CNS, the affected child had remarkable right-side predominant eye-ball hypoplasia with bilateral anterior chamber dysgenesis (microcoria). Brain MRI revealed grossly normal development in the cerebrum, cerebellum, and brain stem. Auditory brainstem responses were bilaterally blunted, suggesting a defective auditory system. At autopsy, both kidneys were mildly atrophied with persistent fetal lobulation. Microscopic examination showed a diffuse global sclerosis. However, despite of the smaller size of glomeruli, the nephron number remained similar to that of the age-matched control. Whole-exome sequencing revealed that the affected child was compound heterozygous for novel truncating LAMB2 mutations: a 4-bp insertion (p.Gly1693Alafs*8) and a splicing donor-site substitution (c.1225 + 1G > A), presumably deleting the coiled-coil domains that form the laminin 5-2-1 heterotrimer complex.

CONCLUSIONS

Our case represents a variation of Pierson syndrome that accompanies CNS with unilateral ocular hypoplasia. The average number but smaller glomeruli could reflect either mal-development or glomerulosclerosis. Heterogeneous clinical expression of LAMB2 defects may associate with the difference in fetal β1 subtype compensation among affected tissues. Further study is necessary to evaluate incidence and features of auditory defect under LAMB2 deficiency.

Regulatory T cells and CTLA-4 in idiopathic nephrotic syndrome

The pathogenesis of idiopathic nephrotic syndrome (INS) remains unknown. Recently, it was postulated that suppression of regulatory T cells (Treg) leads to massive proteinuria in INS, although there is some controversy. Considering the important role of cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) in Treg-mediated immune suppression, the aim of this study was therefore to clarify the involvement of Treg and CTLA-4 in the pathogenesis of INS. Fifteen patients with INS were enrolled. Their blood was sampled twice, once at onset and once at remission induced by glucocorticoid. Although median Treg number was significantly lower at onset than in healthy children, it increased at remission. Similarly, serum CTLA-4 concentration significantly increased at remission compared with onset. Furthermore, a positive significant correlation was observed between Treg number and serum CTLA-4 level. This suggests that Treg and CTLA-4 are involved in the induction of remission in INS.

Novel use of rituximab for steroid-dependent nephrotic syndrome in children

BACKGROUND

Though rituximab (RTX) is effective for childhood steroid-dependent nephrotic syndrome (SDNS), an established regimen does not exist. The relapses tend to occur when the peripheral blood B-cell count re-arises at 3 months upon single RTX infusion. This study was conducted to clarify whether the long-term remission of SDNS can be obtained by repeated RTX administrations.

METHODS

RTX was administered 4 times at 3-month intervals at 375 mg/m(2)/time to 5 children with SDNS. The changes in the clinical indicators were analyzed.

RESULTS

The median (range) observation period was 6.3 (0.9-8.4) years before RTX and 3.2 (1.9-3.8) years following the commencement of RTX. The changes in the clinical indicators were as follows (median and range): (1) annual number of relapses: before administration 1.4 (1.1-3.5) times/year, after administration 0.0 (0.0-0.0) times/year, and (2) median steroid dosage: before administration 0.80 (0.23-0.96) mg/kg/day, after administration 0.00 (0.00-0.00) mg/kg/day. All changes were significant at p < 0.05. Relapse occurred 3 times following the start of RTX (the period to relapse was 2.2, 1.9, and 2.3 years, respectively). No serious side effects were seen.

CONCLUSIONS

Repeated RTX against SDNS in children may be a useful therapeutic option.

Close association between proteinuria and regulatory T cells in patients with idiopathic nephrotic syndrome

BACKGROUND

Idiopathic nephrotic syndrome (INS) has been considered to be a T cell disorder. Supporting this hypothesis is the reported occurrence of remission following measles infection, which suppresses T cell function. In contrast, there has been no case report suggesting an association between influenza B virus infection and the remission of INS.

CASE-DIAGNOSIS/TREATMENT

We report the case of a 5-year-old boy with INS who achieved remission without steroid treatment in response to influenza B virus infection. Although he relapsed soon after remission, he was successfully treated with prednisolone. Both the induction of remission and the response to prednisolone were associated with an increase in the number of circulating regulatory T cells (Tregs), assessed as CD4(+)CD25(+)Foxp3(+) cells. These results suggest that both influenza B virus infection and steroid administration increased the number of circulating Tregs, thus leading to the remission of INS.

CONCLUSIONS

In summary, our case indicates an important role for Tregs in the development of the proteinuria associated with INS and sheds light on its pathogenesis. Further studies are warranted.

Pancreatic involvement in patients with Sjögren's syndrome and primary biliary cirrhosis

Serum pancreatic enzyme activities, exocrine pancreatic function, and pancreatic ductal morphology were evaluated in patients with one or both of Sjögren's syndrome and primary biliary cirrhosis. Ten of 20 patients with Sjögren's syndrome (50%), 6 of 17 patients with primary biliary cirrhosis (35%), and 4 of 11 patients with both diseases (36%) had an elevated level of at least one pancreatic enzyme, including elastase-1, lipase, and trypsin. Diminished excretion of N-benzoyl-L-tyrosyl-para-aminobenzoic acid was observed in 3 of 17 patients with Sjögren's syndrome (18%), 4 of 16 with primary biliary cirrhosis (25%), and none of 7 with both diseases. Endoscopic retrograde pancreatograms demonstrated an abnormal pancreatic ductal configuration in 3 of 11 patients with Sjögren's syndrome (27%), 2 of 9 with primary biliary cirrhosis (22%), and 3 of 4 with both diseases (75%). Only minimal changes in branches of the pancreatic duct were observed in the pancreatogram. Finally, 9-30% of patients with Sjögren's syndrome and/or primary biliary cirrhosis had a mild and intermittent abdominal pain. These findings support the concept of a disease complex, "autoimmune exocrinopathy," in patients with Sjögren's syndrome, primary biliary cirrhosis, and chronic pancreatitis.

Effects of carbamylcholine chloride on human antral gastrin mRNA levels

The effects of the muscarinic receptor agonist, carbamylcholine chloride (carbachol), on gastrin release and gastrin mRNA levels in human antral mucosa (n = 15) were determined. During a-2-h incubation period, carbachol (10(-6)-10(-4) M) decreased gastrin mRNA levels to 71 +/- 8% (10(-6) M), 40 +/- 8% (10(-5) M), and 33 +/- 5% (10(-4) M) of control levels. Carbachol (10(-5) M) decreased intracellular gastrin (from 1634 +/- 103 to 1272 +/- 126 pg/mg tissue protein), while it increased gastrin release into the medium (from 609 +/- 48 to 918 +/- 68 pg/ml per mg tissue protein). After 6- and 9-h culture, carbachol gradually increased gastrin mRNA levels, by 96 +/- 12% and 126 +/- 23%, respectively. Atropine sulfate (10(-5) M) completely inhibited the carbachol-induced changes. Cycloheximide markedly decreased tissue gastrin concentration, but increased gastrin mRNA levels, whereas it had no effects on gastrin release. These findings suggested that carbachol may have a time-related biphasic action on human antral gastrin biosynthesis.

Identification of autoantibodies to a pancreatic antigen in patients with idiopathic chronic pancreatitis and Sjögren's syndrome

A serum autoantibody to a pancreatic antigen was identified in patients with idiopathic chronic pancreatitis and Sjögren's syndrome by radioimmunoassay and Western immunoblotting. Antigen from porcine and human pancreas extracts was partially purified using a monoclonal antibody, SP3-1, which recognizes the antigen in duct cells of various exocrine organs. Solid phase radioimmunoassay of the pancreatic antigen showed a positive result in 6 of 20 patients with idiopathic chronic pancreatitis (30%), 3 of 11 patients with Sjögren's syndrome (27%), and 1 of 15 patients with alcoholic chronic pancreatitis (7%). Among seven patients with stone-related chronic pancreatitis, six patients with autoimmune thyroiditis, and 14 normal controls, none showed evidence of autoantibodies to the pancreatic antigen. Western immunoblotting showed that serum antibody commonly reacted with a 60-kD molecule of either porcine or human pancreatic antigen, with which SP3-1 also reacted. These results show the existence of the autoantibodies to pancreas, especially to an antigen expressed in ductal cells of exocrine glands, in idiopathic chronic pancreatitis and Sjögren's syndrome, and suggest the possibility of an autoimmune mechanism in the pathogenesis of idiopathic chronic pancreatitis.

Distribution of collagen IV in human ocular tissues

PURPOSE

To examine the distribution of the collagen alpha 1(IV) chain and a novel collagen alpha(IV)-related chain in human ocular tissue.

METHODS

Two monoclonal antibodies, JK199 and M3F7, against the alpha 1(IV) chain, and one monoclonal antibody, JK132, against a novel alpha(IV)-related chain were used in the avidin biotin peroxidase complex procedure of immunohistochemical studies. In situ hybridization and reverse transcription polymerase chain reaction were used to examine the presence of alpha 1(IV) messenger RNA in corneal epithelium.

RESULTS

Our data indicate that monoclonal antibodies JK199 and M3F7 react with most ocular basement membranes, but not with those of corneal epithelium. Similarly, monoclonal antibody JK132 reacts with most basement membranes of ocular tissues, with the exception of the inner limiting membrane of neural retina, Bruch's membrane, and corneal epithelial basement membrane. To examine if the epitopes recognized by the monoclonal antibodies were masked in corneal epithelium, the tissue sections were subjected to limited enzyme digestion, that is, pepsin, hyaluronidase, trypsin, and pronase E, or chemical treatments such as 0.1 N NaOH or 6 M urea. Proteinase treatment removed the JK132 epitope from all ocular basement membranes examined. Despite the pretreatment, corneal epithelial basement membrane was not stained by any of the monoclonal antibodies. However, the alpha 1(IV) messenger RNA was detected in corneal epithelium by in situ hybridization and reverse transcription polymerase chain reaction. Western immunoblotting indicates the presence of the alpha 1(IV) and the novel alpha(IV)-related chain in the basal lamella of corneal epithelium.

CONCLUSIONS

The epitopes recognized by JK199, M3F7, and JK132 are masked in basement membrane of corneal epithelium. Based on the tissue distribution and partial amino acid sequences of peptides recognized by JK132, the novel alpha(IV)-related chain differs from other known alpha(IV) chains.

Semiquantitative analysis of the effects of fixation and paraffin embedding on immunoreactivity of renal basement membranes to a monoclonal antibody against type IV collagen

The effects of formalin fixation and paraffin embedding on the immunoreactivity of human kidney to a monoclonal anti-type IV collagen antibody (JK-199) were examined semiquantitatively by a modified enzyme-linked immunosorbent assay (ELISA). The intensity of immunoreactivity in paraffin sections of the tissue fixed overnight with 10% formalin was approximately 70% of that in frozen sections. Immunoreactivity reduced to this extent did not impair the specific staining of basement membranes. Paraffin sections of tissues fixed 2 days showed 50-60% of the reactivity in the frozen sections of the tissue fixed overnight; the basement membranes in Bowman's capsules were stained positively, but those in other sites were not. The paraffin sections of tissues fixed 7 or 14 days showed no specific immunostaining. The immunoreactivity for type IV collagen in the basement membranes was restored after treatment with pronase E. The immunoreactivity after the enzymatic treatment was about 150% of that in the frozen sections of the overnight fixed specimens.

A novel chain of basement membrane-associated collagen as revealed by biochemical and immunohistochemical characterizations of the epitope recognized by a monoclonal antibody against human placenta basement membrane collagen

Biochemical and immunohistochemical characterizations of the epitope recognized by a monoclonal antibody, JK-132, originally produced against human type IV collagen showed that it was distinct from the previously reported monoclonal antibody, JK-199 (Kino et al, J Biochem 1988, 103:829-835). The bound fraction of a crude pepsin extract of human placenta on JK-132 antibody-coupled resin showed close similarity to type IV collagen in a triple-helical conformation in terms of the amino acid composition and circular dichroism spectrum. Sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis of the fraction showed six peptide bands with molecular weights of 50,000 or below, both before and after reduction. Four of the peptides reacted with JK-132 on immunoelectroblotting, but none reacted with JK-199. JK-132 reacted with two additional bands with molecular weights of 100,000 and 120,000, which were not visible on direct staining with Coomassie Brilliant Blue R-250. Two peptides (molecular weights 40,000 and 15,000) bound on a JK-199 antibody affinity column were sequenced, and both contained the same amino-terminal sequences as alpha 1(IV) chain. Conversely the sequences of three of the peptides (molecular weights 50,000, 32,000, and 23,000) eluted from a JK-132 antibody affinity column did not match either the alpha 1(IV) or the alpha 2(IV) sequence reported. Immunohistochemically, JK-132 reacted strongly with basement membranes of blood capillaries in skeletal muscle tissues but not with the basement membranes of muscle fibers in frozen sections of periodate-lysine-paraformaldehyde-fixed tissue, suggesting heterogeneity or tissue specificity of basement membrane collagen. By immunoelectron microscopy, the reaction products were found on the basal laminae of endothelium and of smooth muscle cells around blood vessels. These findings suggest the presence of a new collagen chain associated with basal laminae.

[Serum level of vascular basement membrane associated collagen by the sandwich ELISA with monoclonal antibodies and its clinical significance in various diseases]

A sandwich ELISA system for detecting vascular basement membrane associated collagen (BAC) was developed. Serum levels of BAC were determined in patients with liver diseases (N = 53), various cancers (N = 65) and other diseases (399). Serum levels of procollagen type III (PIIIP) amino propeptide, type IV collagen.7s domain (7s domain) and other parameters (TP, ALB, GOT, GPT, CHE, gamma-GTP, ALP, LDH, CHE, TG, GLU) were also determined in those patients. In the whole patients, serum concentrations of BAC showed a weak correlation with GOT, GPT, ALB and CHE but not with gamma-GTP and ALP. There was no correlation between BAC and PIIIP or 7s domain. Although serum levels of BAC were elevated in both liver diseases and cancers, the increase in liver diseases was more marked. Markedly increased serum levels of BAC with low levels of CHE were found only in liver cirrhosis and liver cirrhosis plus hepatocellular carcinoma. Increased BAC may reflect capillarization of the liver sinusoid or remodeling of the vascular basement membrane which is observed in the progression of liver fibrosis. Serum BAC is thought to be a promising new marker, different from PIIIP or 7s domain for diagnosing fibrosis state in the organs, particularly in the liver.

The effect of fixatives and paraffin embedding on the histochemical reactivity of a monoclonal antibody against human type IV collagen (JK-199)

A new monoclonal antibody (JK-199) was found to react with basement membranes on paraffin-embedded tissue sections without prior enzyme digestion. JK-199 was shown to react with isolated type IV collagen treated by any of four different fixatives--PLP, 4% formalin, modified Zamboni's (0.2% picric acid, 4% paraformaldehyde in 0.1 M phosphate buffer, pH 7.4) or Bouin's--applied for 6 h at room temperature and incubated at 60 degrees C for 30 min to simulate routine tissue processing. None of the fixatives was able to alter the reactivity of JK-199 with isolated type IV collagen. In the human placenta, specific and intense staining of basement membranes was demonstrated on paraffin sections fixed with any of the four fixatives. In human skin, basement membranes were fully demonstrated on paraffin sections fixed by PLP fixative or by 4% formalin, but only partially on sections fixed by picric acid-containing fixatives. Optimal results, i.e., with the least non-specific or incomplete staining, were obtained on PLP-fixed paraffin-embedded tissues. In PLP-fixed paraffin sections of the kidney, skeletal muscle, and small intestine, all basement membranes were stained intensely by this antibody (JK-199) at the expected locations. The results indicate that JK-199 may be widely applicable for the analysis of basement membrane kinetics, including developmental processes or pathological conditions.

Partial characterization of an unusual 185 kDa protein synthesized by dermal fibroblasts from patients with Marfan syndrome: identification of the protein as type IV collagen

Production of an unusual collagenous protein was observed in culture of dermal fibroblasts from four patients with Marfan syndrome. The apparent molecular weight of the protein was about 185 kDa after reduction with 2-mercaptoethanol and 175 kDa after limited pepsin treatment. The 185 kDa protein was susceptible to the bacterial collagenase but resistant to the animal collagenase. Immunoprecipitation revealed the specific interaction of the pepsin-treated 175 kDa collagenous protein with monoclonal and polyclonal antibodies to human type IV collagen. From the patterns of CNBr peptide mapping the 185 kDa band was identified as alpha 1 (IV) chain. Type IV collagen in the skin is generally considered to be of non-fibroblastic origin. However, in "diseased" condition, dermal fibroblasts might produce type IV collagen. The clinical manifestation in relation to production of type IV collagen by cultured skin fibroblasts from Marfan patients is discussed.

Characterization of a monoclonal antibody against human placenta type IV collagen by immunoelectroblotting, antibody-coupled affinity chromatography, and immunohistochemical localization

We have produced four monoclonal antibodies against type IV collagen obtained from human placenta. An antibody with a high titer by ELISA, named JK-199, reacted not only with type IV collagen in the triple-helical conformation but also with thermally denatured chains. After affinity chromatography on JK-199 antibody-coupled resin, the amino acid composition and CD spectrum of the affinity-purified peptides from the crude pepsin extract of human placenta were typical of those of human type IV collagen in the triple-helical conformation. On SDS-polyacrylamide gel electrophoresis, the purified protein showed only one broad band with a molecular weight of approximately 260,000 before reduction and six smaller peptide bands after reduction. On immunoelectroblotting, JK-199 reacted with all six peptide bands. Immunohistochemically, typical basement membranes were exclusively and strongly stained with JK-199 on frozen sections of PLP-fixed human placentas without any enzymatic pretreatment in the routine immunoperoxidase method. Judging from these findings, it is concluded that the epitopes of type IV collagen that reacted with JK-199 are exposed on the surface of basement membranes. This antibody should be useful for identification of type IV collagen in normal or pathological basement membranes or other structures.

Immunohistochemical study of beta-adrenergic receptors in the psoriatic epidermis using an anti-alprenolol anti-idiotypic antibody

In order to study the beta-adrenergic receptor-cyclic AMP system in the human skin, we have developed a monoclonal antibody against the receptor binding site in two fusion steps. We produced an anti-alprenolol monoclonal antibody using a hybridoma technique after the immunization of a mouse with alprenolol-BSA conjugate. This antibody was then used to immunize mice, whose splenocytes were used for the second fusion. Colonies were screened by enzyme linked immunosorbent assay (ELISA) using turkey erythrocyte membrane as an antigen. One of the positive colonies was grown in mice to obtain ascites fluids. This antibody showed the ability to compete with [125I]-iodocyanopindolol for the binding to beta-adrenergic receptors of turkey erythrocytes. The binding of the antibody to the turkey erythrocytes was prevented by the existence of the anti-alprenolol antibody and also L-alprenolol. This antibody showed a prominent inhibition of the adrenaline-stimulated adenylate cyclase activity of the turkey erythrocyte membrane. The data indicate that the anti-idiotypic monoclonal antibody against alprenolol binds to the beta-adrenergic receptors and acts like an antagonist. We further studied the localization of the beta-adrenergic receptors with this antibody in the normal human skin as well as in the psoriatic skin using immunohistochemical technique. A prominent decrease of the beta-receptors was observed in the psoriatic epidermis.

Monoclonal antibodies against epidermal cell surface and dermal-epidermal junction: antigens which may be epidermal cell spreading factors

Two monoclonal antibodies which reacted with the epidermal cell surface (SF-1) and the dermal-epidermal-junction (SF-2), respectively, were obtained by immunizing mice with partially-purified human epibolin. The corresponding antigens were partially purified from fetal bovine serum by affinity chromatography using these antibodies. SDS-polyacrylamide gel electrophoresis showed that these antigens contained polypeptide components with molecular weights different from that of epibolin (mol. wt. 65,000 daltons); SF-1 antigen had a 68,000 dalton main component, and SF-2 antigen a broad 58,000-61,000 dalton main component. Both of these partially-purified antigens promoted the spreading of dissociated pig epidermal cells. SF-2 antigen also promoted the spreading of Pam cells (a murine keratinocyte line). The results suggest that proteins capable of promoting epidermal cell spreading may be present on the epidermal cell surface and at the dermal-epidermal junction. However, their physiological role in keratinization remains to be elucidated.

Monoclonal antibodies to the beta-adrenergic receptor: modulation of catecholamine-sensitive adenylate cyclase by the antibody

We have developed two types of hybridomas producing monoclonal antibodies to the turkey erythrocyte beta 1-adrenergic receptor in order to study the beta-adrenergic-cAMP system of epidermis. Splenic cells from BALB/c mice immunized with partially purified turkey erythrocyte beta 1-receptors were fused with mouse myeloma cell line SP2/0-Ag14. Five hybridomas of 17 positive cells producing antibodies which could precipitate soluble turkey erythrocyte beta 1-receptors were cloned by the limiting dilution method. The antibodies cross-reacted with beta 1- and beta 2-adrenergic receptors and stained epidermal basal cells with immunocytochemical techniques. Neither type of antibody interfered with the antagonist binding, i.e., all antibodies bound to sites other than the ligand binding site on the surface. One type of antibody inhibited epinephrine-stimulated adenylate cyclase activity in our "leaky" epidermal cell system. The data suggest that the antibody interferes with the coupling of the receptor to the regulatory protein.

A cell-spreading inhibitor exists in serum and in epidermal basal cells

A unique monoclonal antibody was obtained by immunizing mice with complement-inactivated fetal bovine serum (FBS). This antibody, named SI-1, stained epidermal basal cells of humans, pig, guinea pig, and rat by an indirect immunofluorescence technique after pretreatment of cryostat sections with alkali buffer (pH 9.6). After dissociating pig epidermal cells by trypsin, the SI-1 antibody stained exclusively and strongly one type of uniquely shaped cells. They were small and hanging-bell or columnar in shape with one convoluted side on the base, consisting of less than 2.8% of the dissociated epidermal cell population. The antigen contained in FBS was partially purified by affinity chromatography using the SI-1 antibody. The affinity-purified antigen inhibited the spreading of PAM cells, a spontaneously transformed murine keratinocyte line, in serum-free medium in a dose-dependent manner at concentrations of 10(-5) to 10 ng/ml. The antigen also inhibited the spreading of trypsinized pig epidermal cells in the range of 10(-2) to 10(3) ng/ml in the presence of 0.05% FBS. Although there have been a few reports indicating that serum inhibited both spreading and attachment, a specific factor in serum has not been purified before. This is, to our knowledge, the first presentation of a cell-spreading inhibitor contained in serum.

Successful preparation of cobalt(II)-substituted hemocyanin

The cobalt(II)-substituted hemocyanin was first prepared by dialysis of apohemocyanin against Tris-HCl buffer (pH 8.0) containing cobalt(II) ion. The amount of cobalt(II) introduced into apohemocyanin reached 47% of the total sites for copper ion in native hemocyanin, being estimated as nearly complete formation of the half-filled cobalt(II)-hemocyanin (Co(II)-Hc). The Co(II)-Hc did not bind oxygen molecule even under O2-atmosphere. The spectral data indicated that the Co(II) is in tetrahedral geometry (high-spin state).

Studies on the examination of imported laboratory monkey, Macaca fascicularis for E. histolytica and other intestinal parasites

Infection rate of imported monkeys, under this study, with intestinal protozoa is higher than the infection rate with intestinal nematodes. Mostly encountered protozoa were E. coli, E. nana, E. histolytica and I. butschlii. Formalin-Ether concentration method yielded higher % positive for E. histolytica than the culture method using Tanabe-Chiba medium, but the results obtained from these 2 methods correlate perfectly well with each other. Efficacy of thiabendazole against intestinal nematodes such as Strongyloides, Trichuris, Physaloptera, Oesophagostomum and Capillaria was very satisfactory.