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Inhibition of complement mediated solubilization (CMS) of preformed immune complexes was previously demonstrated in the serum of patients with systemic lupus erythematosus. We studied the ability of serum from patients with MPGN I or III to inhibit the solubilization of preformed BSA anti-BSA aggregates by pooled normal human scrum. Inhibition of CMS was found in the sera of 20/35 patients; the inhibition was more dramatic in those with active disease (9/9), as compared to those in remission (8/21) or with renal failure (3/5). The inhibition did not seem to be related to corticosteroid therapy, nephrotic syndrome, circulating immune complexes or hypocomplementaemia. In only one patient was inhibition associated with the presence of C3 nephritic factor activity and decomplementation of the target serum. [ABSTRACT FROM AUTHOR]

Activation of C4 releases into the fluid phase a fragment of the alpha chain, C4a. Unlike the analogous fragments of C3 and C2, there is no evidence for an anaphylatoxic effect of C4a. There is actually some in vitro evidence that it could have a modulating effect on inflammation by inhibiting monocyte chemotaxis. We induced an immune complex glomerulonephritis in wild-type (WT) and C4 knock out (C4KO) mice. Although the glomerular component of the disease did not differ in the two groups of animals, there were marked differences in the accompanying tubulo-interstitial injury. Compared to WT animals, the C4KO mice had significantly more infiltrating interstitial cells (1910 vs 2720/mm(2)), foci of tubular atrophy (6.3 vs 14.8/section), and interstitial space (22 vs 30% of cortex). C4 is expressed constitutively by renal tubular epithelial cells. These data support a role for such local C4 in modulating interstitial inflammation, consistent with in vitro experiments., ((c)2001 Elsevier Science.)

An association between the complement system and immune complex glomerular disease in humans has long been recognized. In fact, much of our early understanding of the immunochemistry of complement activation developed with the study of acute and chronic glomerulonephritis (1). This manuscript will examine associations between glomerulonephritis and the three complement components encoded within the major histocompatibility complex: C4, C2, and factor B (B). The mechanisms by which deficiencies or polymorphisms in these components can mediate disease will be examined.

C57/B6 mice received intraperitoneal horse spleen apoferritin (4 mg) with lipopolysaccharide (0.05 mg); control mice received 0.15 M NaCl. Control and treated animals were killed weekly for 6 wk; blood and urine specimens were obtained, and tissue samples were secured. Treated animals showed evidence of significant chronic disease, with proteinuria, hematuria, and uremia. A mild glomerulonephritis was present at 2 wk, with significant proliferative glomerulonephritis at 4 wk, progressing to chronic disease with tubulointerstitial changes at 6 wk. Changes at each time period were uniform between animals. C3 mRNA was first detected by in situ hybridization at 3 wk. Message was restricted to proximal tubular and periglomerular epithelial cells. Presence of C3 message preceded the development of interstitial inflammation and fibrosis by 1-2 wk, and its location and intensity paralleled the evolving interstitial disease. Although extensive mesangial C3 protein deposits appeared early, there was never C3 message in glomeruli or infiltrating cells. Before C3 message became apparent, two cytokines known to up-regulate C3 transcription in vitro, IL-1 and IL-6, were detected by immunohistochemistry. The temporal sequence in this model is consistent with our hypothesis that local synthesis and activation of C3 in tubular epithelium is important to the interstitial component of chronic glomerulonephritis. The process is independent of the deposition of circulating complement in the glomerulus, but may be triggered by glomerular cytokines.

Objective: To improve compliance with the completion of speakers' evaluation forms in a pediatric hospital continuing medical education program., Design: Preintervention and postintervention analysis., Setting: Pediatric hospital in Cincinnati, Ohio., Participants: Attendees at pediatric grand rounds programs., Main Outcome Measure: Analysis of speaker evaluation forms for each of 20 pediatric grand rounds programs were used as the basis for speakers' awards., Results: Spontaneous written comments were found on a mean of 7.3 evaluations per preintervention program and 13.5 evaluations per postintervention program (P<.01). The distribution of objective scores in 3 items examined was wider postintervention than preintervention (P<.01)., Conclusion: When participants in continuing medical education programs know that their evaluations of an activity are used as the basis for an educational award, they may be more reflective in completing such evaluations.

The calciotropic activity of urine from a subject with neonatal Bartter syndrome (NBS) has been partially purified using ion-exchange and gel chromatographic techniques. A bioassay using bone disks from rat calvaria was used to estimate calciotropic activity, which in the urine of the subject with NBS appears to be due to basic fibroblast growth factor (bFGF) bound to a glycosaminoglycan susceptible to heparitinase digestion. The calciotropic activity is eluted from DEAE-Sephacel and Sepharose CL-6B in a narrow band in association with metachromatic material and is destroyed by heparitinase and blocked by an antibody to bFGF. After treatment of purified preparations with heparitinase, a component that is inactive alone but develops calciotropic activity in association with heparin can be isolated by affinity chromatography on heparin-Sepharose columns. This component is recovered from the column at NaCl concentrations expected to elute bFGF and is inactivated by antibodies to bFGF. No calciotropic activity can be shown in glycosaminoglycan-containing fractions from urine from a normal boy or a normal man, but such fractions exhibit calciotropic activity if bFGF is added to the assay system. When bFGF is added to urine from either normal subject followed by ion-exchange chromatography on DEAE-Sephacel, calciotropic activity is eluted at NaCl concentrations closely similar to those found to elute calciotropic activity from the urine of the NBS subject. It appears that the abnormal findings in NBS urine are due to excess bFGF, although they could be due to some abnormality of the glycosaminoglycan component.

Objective: The superficial location of renal transplants places them at risk for traumatic damage. Significant injuries have been reported from automobile seat belts, for example. This study was designed to assess the potential for direct transplant injury from the use of climbing harnesses., Methods: Ten patients with kidney transplants were fitted with a variety of climbing harnesses after the locations of their grafts were defined., Results: With the exception of two harnesses in a single patient, all devices came into contact with all transplants., Conclusion: Sports requiring the use of climbing harnesses (eg, rock climbing, rappelling, and challenge course participation) may be unsafe for recipients of kidney transplants.

Colabeling with complement compont C1q or immunoglobulin M (IgM) is occasionally reported in biopsy specimens from patients with IgA nephropathy. The significance of this finding has been questioned. In 83 children and young adults with otherwise typical IgA nephropathy, 15 patients had more than trace mesangial labeling for IgM or C1q. Of these, 14 patients (93%) had greater than 1 + proteinuria at the time of biopsy. This was in marked distinction to the patients with no mesangial labeling for these reactants, only 15% of whom had greater than 1 + proteinuria. The children with IgM or C1q colabel did not differ from those lacking this finding in age at presentation, length of follow-up, or current renal function. In childhood IgA nephropathy, colabeling with IgM or C1q is seen frequently, probably is a function of heavy proteinuria at the time of biopsy, and does not contribute adversely to outcome.

The neonatal Bartter syndrome (NBS) is associated with a complex disorder of mineral metabolism in children, including hypercalciuria, nephrocalcinosis, and diminished bone mineral density. Although cyclooxygenase inhibition usually brings about improvement in these findings, there is a variable component which is resistant to such therapy in many children. The factor mediating this disorder has not been identified. Blood and urine from 12 children with NBS were examined. When compared with samples from normal children and adults, all (NBS) sera reduced bone calcium uptake in a bone disc bioassay. This effect persisted in the presence of parathyroid hormone (PTH) antibody and PTH receptor blockade, indicating that neither PTH nor PTH related peptide was responsible. It was eliminated by indomethacin, suggesting that prostanoid generation was essential. Protamine was also inhibitory, as was the addition of ecteola, an anion binder. Activity could be recovered from ecteola by elution with hypertonic buffer. Urine samples from children with NBS had the same calcitropic effect. The agent was removed by ecteola and recovered by hypertonic elution. Activity was eliminated by protamine and by heparinase, but not by trypsin digestion. Size exclusion centrifugation showed that the activity was associated with a material between 10 and 30 kilodaltons. Finally, urine ecteola eluates from NBS patients raised serum concentrations of calcium after intraperitoneal injection in rats. These data suggest that children with NBS have a calcitropic substance in their serum and urine which is not found in normal individuals. The substance is heparin like, and mediates its effects through prostanoid production. These studies provide additional evidence against a direct renal cause of the urinary calcium disturbance characteristic of the disorder.

During renal transplantation, the donor ureter is normally anastomosed to the recipient bladder. However, preexisting anomalies of the lower urinary tract or previous surgical interventions may render the recipient bladder unusable. Although in such situations urine may be externalized via cutaneous ureterostomy or an ileal conduit, both techniques are frequently complicated by bacterial colonization or chronic infection. To overcome these problems, the authors have been treating such children via extensive, staged, bladder reconstruction (augmentation) before transplantation. On rare occasions, however, the absence of a usable bladder necessitates the creation of a complete neobladder from other visceral tissues. The authors present two cases in which patients underwent complete anatomic reconstruction of the lower urinary tract before renal transplantation. This approach results in the optimal environment for allograft function and leads to a greater rehabilitation than that achieved with urinary diversion.

Complete deficiency of the complement C4A isotype is a known genetic risk factor for systemic lupus erythematosus (SLE). The disease phenotype of C4A-deficient patients has never been defined. Among 200 patients with SLE from five centers, 18 (9%) with C4A deficiency were identified. These individuals were compared to those who were C4A replete with regard to a series of clinical and serologic features. The only significant differences between the two groups were in the presence of renal disease (C4A deficient, 11%; C4A replete, 46%; P < 0.006) and a decrease in the serum concentrations of C3 (C4A deficient, 11%; C4A replete, 35%; P < 0.04). There was also a trend for the C4A-deficient individuals to have milder disease. In light of the tendency for C4A-deficient individuals to have lower serum concentrations of C4, it is important that such patients not be subjected to overly aggressive efforts to "normalize" their C4 levels.

We performed a detailed clinical review and pathologic analysis of the kidney biopsies of 134 children with nephrotic syndrome or asymptomatic proteinuria. This analysis challenges some of our concepts about the classification of conditions associated with these disorders. The presence of focal segmental sclerotic lesions does not define a unique disorder in childhood. Some children with such lesions will have unaffected glomeruli that are ultrastructurally completely normal. These patients, predominately black adolescents, present either with nephrotic syndrome or asymptomatic proteinuria. We classify this disorder as primary focal segmental glomerulosclerosis (FSGS) and have never found it to recur after transplantation. Most other children with FSGS have 1 of 2 specific glomerulopathies. Those with minimal change have generalized fusion of podocyte foot processes. Those with mesangial proliferation have similar foot process changes combined with mesangial expansion and proliferation and, frequently, thinning of the lamina densa and tubuloreticular inclusions. The presence of segmental lesions in these glomerulopathies appears to be nothing more than a marker of severity. Children with these glomerulopathies are generally younger white children, virtually all of whom have nephrotic syndrome. These disorders have a strong propensity to recur after transplantation. The presence of mesangial labeling of IgM or C1q has no significance in any of these 3 disorders. The classification of disorders associated with nephrotic syndrome or asymptomatic proteinuria must concentrate less on the presence or absence of focal sclerosis and more on the histologic appearance of the rest of the glomeruli.

Patients with hereditary C4 deficiency are likely to have severe lupus erythematosus. A patient with hereditary angioneurotic edema (HANE) and systemic lupus erythematosus (SLE) had a chronic deficiency in C4 because the hereditary deficiency in C1-inhibitor allowed the C1 in her serum to become activated and then inactivate C4. An attempt was made to repair the C4 deficiency as well as the deficiency in C1-inhibitor by giving infusions of human C1-inhibitor in the hope of inducing remissions of both HANE and SLE. During treatment, antibody to C1-inhibitor developed in the patient; this cleared when the infusions were stopped. During subsequent treatment with danazol alone, measurable C1-inhibitor developed in the patient's serum, but levels of C4 were never significantly increased. Antibody to normal C1-inhibitor was not expected to develop in the patient because she is heterozygous for this autosomal dominant trait. A normal allotype (VAL or MET 458), which would have been in the preparation used but which the patient does not synthesize because she can produce only one allotype (MET 458), appears to have been immunogenic. The antibody isolated from the patient's serum reacted with C1-inhibitor from a normal individual known to be homozygous for 458-VAL but not with one from a homozygote for MET-458.

We have previously demonstrated regulated expression of C3 in the proximal renal tubular epithelial cells of humans. To test the hypothesis that local alternative pathway complement activation could contribute to the tubulointerstitial component of chronic renal disease, we examined factor B gene expression in human kidneys. 35S riboprobes were generated from a human factor B cDNA. By in situ hybridization, proximal tubular factor B message was seen in 17 kidneys with various nephropathies. The expression was most intense in organs with evidence of interstitial inflammation, and its localization paralleled the inflammation. As was the case with C3 and C4, there was never any evidence of glomerular factor B message, nor was any seen in infiltrating inflammatory cells. In eight normal kidney tissues, factor B expression was either absent or restricted to rare foci of interstitial infiltration. The proximal renal tubular epithelium of humans appears to express the genes for both components of the alternative pathway convertase, C3 and factor B. These locally produced components may be important mediators of the interstitial inflammation that is common to all progressive nephritides.

The human insulin-like growth factor type 2 receptor gene (IGF2R) is biallelically expressed in a variety of fetal and adult tissues. In contrast, the imprinted mouse Igf2r gene is expressed exclusively from the maternally inherited chromosome. The mouse gene contains two CpG islands that are methylated in a parent-specific manner. Methylation of the CpG island in the promoter region occurs on the repressed paternal gene copy. Methylation of the CpG island in intron 2 is specific for the active maternal allele and may represent the primary imprint. Here, we have analyzed the human IGF2R gene to investigate whether these motifs and their parent-of-origin-specific epigenetic modification have been conserved. As in the mouse, the human IGF2R gene was found to contain two CpG islands, one encompassing the transcription start site (CpG 1) and the other in the second intron (CpG 2). CpG 2 is hypermethylated on the maternal IGF2R allele. In contrast to the situation in the mouse, however, the human CpG 1 is completely unmethylated on both parental chromosomes. The human and mouse intronic CpG islands lack significant sequence homology, which suggests that DNA conformation plays a role in allele-specific methylation.

Hypercalciuria in the absence of urolithiasis has been considered to be a cause of asymptomatic hematuria. No mechanism for this association has been demonstrated. In an effort to establish the specificity of this association, we induced hypercalciuria in 10 healthy subjects by oral administration of 1,25(OH)2 vitamin D for 10 days. This protocol reproducibly produced markedly increased urinary calcium excretion (mean calcium:creatinine ratio 0.5). Despite this, no subject developed hematuria as seen by dipstick urinalysis or by alteration in erythrocyte Addis counts (mean counts 1.02 x 10(6)/12 h before vitamin D and 0.84 x 10(6)/12 h after 10 days of therapy). This study provides no evidence that short-term hypercalciuria alone produces hematuria in otherwise healthy individuals.

A 15-year-old girl with complete C4 deficiency and a lupus-like disorder developed evidence of nephritis after 4 years of followup. Renal biopsy demonstrated an immune complex glomerulonephritis, with deposits in the capillary loops, the paramesangium, and the mesangial matrix. Renal function was normal. The patient was treated with monthly infusions of intravenous immunoglobulin for 6 months. The treatment was well tolerated, and resulted in resolution of the rash and hematuria. Followup biopsy showed less proliferation and fewer loop deposits. In light of the serious risk of infections that is associated with complement deficiency, approaches to glomerulonephritis that do not include immunosuppression should be considered.

Some patients with hypercalciuria are thought to have enhanced enteric calcium absorption, with a major component of recent diet contributing to urinary calcium. This mechanism has been difficult to test with the usual calcium loading procedures. We employed dual stable calcium isotope tracers to quantitate the components of urinary calcium excretion in 38 healthy female children. The mean urinary calcium excretion in these girls was 2.4 mg/kg per day. The contribution of recent diet to this total was a mean of 0.2 mg/kg per day. The maximum dietary contribution to urinary calcium excretion was 0.86 mg/kg per day. Recent diet contributes a mean of 8% to total dietary calcium excretion. This novel method permits precise quantitation of the contributions of recent diet and tissue stores to urinary calcium excretion. In these healthy girls, the fraction of urinary calcium derived from diet is trivial.

Forty-eight of the 50 state health departments in the United States responded to a questionnaire about giardiasis in their jurisdictions. The agencies had reports of 34348 cases during 1991 and studied 80 outbreaks in the same period. Nineteen of these outbreaks were attributed to consumption of contaminated drinking water; only two outbreaks were reported among individuals identified as campers or backpackers. Only two departments considered water-associated giardiasis to be a problem for backpackers in their jurisdiction, and neither had any data to support this concern. The surveillance data of health departments indicate that giardiasis is a common communicable disease in the United States. They do not, however, provide any evidence that wilderness water is an important cause of the disease in this country.

The blood-borne hepatitis viruses, hepatitis B virus (HBV) and hepatitis C virus (HCV), have similar epidemiological features. The association of chronic HBV infection and glomerulonephritis is well established, particularly in children. Recent reports have shown an association between HCV infection and glomerulonephritis in adults. In order to assess the role of these hepatotropic viruses in membranoproliferative glomerulonephritis (MPGN) we screened 34 children with idiopathic MPGN for the presence of HBV and HCV infection using highly sensitive polymerase chain reaction techniques for the detection of HBV DNA and HCV RNA. Also, enzyme-linked immunosorbent assays were used to detect the presence of antibody to hepatitis B surface antigen and antibody to HCV. No evidence of HBV or HCV infection was demonstrated in any of the patients. We conclude that HBV and HCV are not significant causes of idiopathic MPGN in children in the United States.

We used C3-deficient (C3D) guinea pigs to evaluate the role of C3 in an active model of experimental nephritis. Normal strain 2 (C3N, n = 13) and C3D (n = 6) guinea pigs were immunized with cationized bovine gamma-globulin (CBGG). Fourteen days later (Day 0), daily intravenous injections of CBGG were given for 3 to 7 days and the animals were sacrificed on Day 10 or 21. Immunofluorescence (IF) microscopy of renal tissue revealed two patterns of glomerular IgG deposition: granular loop (11/13 C3N, 3/6 C3D), and predominantly mesangial (2/13 C3N, 3/6 C3D). Codeposited C3 was seen in all C3N and in no C3D animals. Electron microscopy showed subepithelial deposits in all. A significant correlation (P < 0.005) was seen between an animal's IF pattern and its level of serum antibodies to CBGG; those with lower antibody levels exhibited the mesangial pattern. C3D animals had lower mean antibody levels than C3N (P < 0.01), but both IF patterns were represented. Urine protein concentration, which was increased relative to controls, did not differ between C3N and C3D groups, but was significantly greater in those with loop IF. Serum albumin was significantly reduced in animals with loop IF. C3N animals showed a significant reduction in mean serum C3. In this model, immune deposit location and degree of proteinuria are independent of C3 deposition and dependent upon the level of antibody response to CBGG. Induction of antibody to CBGG is impaired in the absence of C3.

Ten patients with Henoch-Schöenlein purpura (HSP) were selected for study because their early renal biopsies showed focal and segmental hypercellularity, with IgA present only in deposits at the periphery of the lobules. Mesangial deposits of IgA were absent. All had laboratory evidence of nephrotic syndrome and/or renal compromise. The glomerular hypercellularity was largely the result of the infiltration of monocytes whose cytoplasm often contained tubular lysosomes and wrapping lysosomal membranes, evidence of monocyte activation. Mean levels of C3 were normal but those of C4 and properdin significantly depressed. This complement profile, as well as a glomerular monocytic infiltrate, are also seen in essential cryoglobulinemia in the adult. Of follow-up biopsies in six patients, the glomeruli were normal in three, with no IgA deposition. In the other three, mesangial deposits of IgA typical of HSP were present. The initial focal-segmental glomerulitis of these patients appeared to be the benign first phase of a disease which had the potential to culminate in mesangial IgA deposition. Patients like the three who escaped mesangial IgA would be among those responsible for the observed dissociation between severity of the initial illness and ultimate prognosis.

We and others have shown an association between autoimmune disorders and the major histocompatibility complex extended haplotype HLA-A1,-B8,-SCO1,-DR3. The primary gene or genes within this haplotype conferring such susceptibility, however, have not been defined. In this study, we tested the hypothesis that linkage disequilibrium in this haplotype extends through the DP locus, and that DP type may be linked to membranoproliferative glomerulonephritis (MPGN) and systemic lupus erythematosus (SLE). DP and DQ typing was performed by restriction fragment length polymorphism analysis for 43 chromosomes (19 healthy controls, 9 SLE, 15 MPGN) bearing the -A1,-B8,-SCO1,-DR3 extended haplotype. Although all were DQw2, a variety of DP types were identified (DPw1, 0.26; DPw2, 0.09; DPw3, 0.14; DPw4, 0.44). Although DPw1 was represented on extended haplotypes with greater frequency than on 113 non-A1,-B8,-SCO1,-DR3 haplotypes (0.26 vs. 0.03; P < 0.001), there were no significant differences between healthy individuals with this haplotype and those with autoimmune disease. We conclude that the strong linkage disequilibrium of this haplotype breaks down between the DQ and DP loci. Loci important to disease susceptibility, therefore, are more likely to occur telomeric to DP.

Metabolic investigations, including the use of stable isotopes of calcium, were used to study calcium kinetics in three children with the hyperprostaglandin E syndrome. The studies were performed both during indomethacin treatment and in the absence of therapy. Off therapy, each child had hypercalciuria (mean urinary calcium excretion 0.478 mM/kg/d), hyperprostaglandinuria, and elevated serum calcitriol concentration. All had diminished bone density and were euparathyroid. Indomethacin treatment was associated with a marked reduction in serum calcitriol concentration, as well as decreased prostaglandin E excretion. Mean urinary calcium excretion fell to 0.135 mM/kg/d. The stable isotope studies defined two components to the hypercalciuria of this disease: an indomethacin-sensitive dietary contribution and a relatively indomethacin-resistant bone resorptive element. Bone densitometry confirmed the presence of the resorptive element by demonstrating skeletal demineralization.

Twenty children and adolescents with IgA glomerulonephritis were enrolled in a crossover trial. Each received 12 weeks of prednisone therapy and 12 weeks of placebo dosing. Urinary protein and erythrocyte excretion were monitored during both courses. There was no evidence that, under the conditions of the study, corticosteroid therapy was effective in IgA nephropathy.