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Biomedical subjects

C F Strife

Publications and source records attributed to C F Strife.

At least 19 recordsLinked to original sources

IgG subclass restriction of autoantibody to solid-phase C1q in membranoproliferative and lupus glomerulonephritis.

The IgG subclass distribution for autoantibodies to solid-phase C1q (anti-spC1q) in sera from 14 patients with membranoproliferative glomerulonephritis (MPGN) and 10 patients with systemic lupus erythematosus (SLE) nephritis was determined by an enzyme-linked immunosorbant assay employing C1q as the immunosorbant in the presence of 2 M NaCl to prevent Fc binding and monoclonal anti-human IgG subclass reagents. The autoantibody to spC1q in MPGN, especially in types I (7 patients) and II (3 patients), was almost entirely restricted to IgG3. In contrast, in SLE anti-spC1q was completely restricted to IgG2 in 3 patients while predominantly IgG2 in the other 7 patients. The different subclass restriction of anti-spC1q in these two disorders suggests that antibody formation is either in response to different epitopes on the collagen-like region of C1q or that patients with SLE and MPGN mount different immunologic responses to the same antigenic stimulus.

Analysis of Variance

Long-term follow-up of non-systemic lupus erythematosus glomerulonephritis in patients with hereditary angioedema: report of four cases.

Hereditary angioedema (HAE) is characterized by a deficiency in C1 inhibitor protein (C1 INH) and by clinical symptoms of episodic swelling of subcutaneous or mucosal tissue. It has rarely been reported in association with non-systemic lupus erythematosus (SLE) glomerulonephritis (GN). A recent report of two cases indicates the prognosis to be poor, with both patients progressing to chronic renal failure 8 and 20 years after diagnosis. This report describes the 5-year follow-up of a previously unreported case of an 8-year-old boy with HAE and non-SLE membranoproliferative glomerulonephritis (MPGN). The patient developed macroscopic hematuria, azotemia, and a vasculitic rash. Treatment included prednisone and cyclophosphamide, resulting in clinical improvement. The present report also summarizes the long-term follow-up of three previously reported cases of HAE and non-SLE GN, 25, 16, and 10 years after their initial presentation. Patients monitored for 25 and 16 years had MPGN and normal renal function and received no therapy. The third patient, monitored for 10 years, had segmental MPGN. This patient presented with urinary abnormalities and, after treatment with prednisone, had improvement in her hematuria. None of these four patients developed chronic renal failure. These observations indicate a variable outcome in patients with HAE and non-SLE GN.

Aged

Rapid improvement in the renal tubular dysfunction associated with tyrosinemia following hepatic replacement.

The postoperative management of patients with hereditary tyrosinemia type I (McKusick 27670) following liver transplantation is often complicated by the renal tubular dysfunction associated with this disease. To characterize better the temporal course of the improvement in renal excretory activity following hepatic replacement, renal tubular function and metabolite excretion were studied in a 4-year-old girl with hereditary tyrosinemia during the immediate post-transplantation course. Tubular reabsorption of bicarbonate and phosphate were normal 5 days following transplantation, in contrast to glucosuria, hyperaminoaciduria, and tyrosyluria, which persisted for approximately 3 weeks. After hepatic replacement, serum amino acid concentrations returned to normal and succinylacetone was no longer detected in the urine. This is the third tyrosinemia patient reported to achieve complete resolution of urinary abnormalities following transplantation, and the only patient in whom renal tubular function was formally assessed within the first postoperative week.

Amino Acid Metabolism, Inborn Errors

Hyperechoic renal medullary pyramids in infants and children.

Fifty-five children (34 boys, 21 girls; age range, 1 day to 18 years) with increased echogenicity of the renal medullary pyramids at ultrasound evaluation were identified. The clinical diagnoses associated with hyperechoic medullary pyramids could be separated based on the presence or absence of hypercalciuria. Patients with drug-induced hypercalciuria included 10 infants treated with furosemide, two treated with long-term steroid therapy, and one treated with excessive amounts of vitamin D. Other clinical conditions associated with hypercalciuria included renal tubular acidosis (n = 10), Bartter syndrome (n = 5), hyperparathyroidism (n = 3), Williams syndrome (n = 2) and medullary sponge kidney (n = 2). Ten children with transient renal insufficiency and three with sickle cell disease had normal urine calcium concentration. Isolated disease entities accounted for the remainder of cases. A specific diagnosis can usually be made in a patient with hyperechoic renal medullary pyramids by using a systematic clinical approach that includes evaluation of patient age, serum and urine calcium concentration, and renal function.

Acidosis, Renal Tubular

Acquired structural genitourinary abnormalities contributing to deterioration of renal function in older patients with nephropathic cystinosis.

The natural progression of nephropathic cystinosis to end stage renal disease can be delayed, sometimes by many years, by the reducing agent, cysteamine, which lowers intracellular cystine content to near normal. We report on two patients with nephropathic cystinosis who were treated with cysteamine and developed structural genitourinary abnormalities which may have contributed to an increase in the rate of decline of renal function. One patient, aged 11 years, was found to have massive megacystis and hydroureteronephrosis but no anatomic bladder outlet obstruction. His abnormality was presumed to be related to chronic high urine volumes leading to megacystis and physiologic ureteral obstruction. Vesicostomy stabilized renal function. The second patient, aged 11 1/2 years, was found to have bilateral renal cystic disease which presumably was acquired and may have been related to long-standing hypokalemia. Minor renal abnormalities were found by ultrasound in five additional cystinotic children. We concluded that older children with nephropathic cystinosis may be prone to acquire structural abnormalities of their kidneys or urinary tract.

Creatinine

Autoantibody to complement neoantigens in membranoproliferative glomerulonephritis.

With the exception of C3 nephritic factor, autoantibody formation has not been commonly associated with membranoproliferative nephritis (MPGN). We measured autoantibodies (nephritic factors) to the C3 convertases C3bBb (NFa) and C3bBbP (NFt), which result in fast and slow C3 activation, respectively, and to a neoantigen on C1q fixed to a solid phase (spC1q) in sera from 29 patients with MPGN type I, 26 with type II, and 28 with type III. Autoantibody formation was common in all MPGN types. An autoantibody to a C3 convertase neoantigen was identified in more than 75% of the hypocomplementemic MPGN sera tested. Anti-C3bBb (NFa) was present in 81% of patients with MPGN type II but was rarely found in either type I or type III. Anti-C3bBbP (NFt) was common in both MPGN I and III. Anti-spC1q was present in 74% of patients with type I and in 38% and 48% of types II and III MPGN, respectively. Patients with MPGN types I, II, and III had one and two serum autoantibodies detected significantly more frequently than did a group of healthy subjects. The presence of any one autoantibody was not specifically associated with the presence of any other autoantibody. The results indicate that multiple autoantibody formation is common in all MPGN types. MPGN II, and possibly MPGN I, tend to form more specific autoantibodies.

Antigen-Antibody Complex

Distribution of target-organ abnormalities by race and sex in children with essential hypertension.

The prevalence of left ventricular hypertrophy, glomerular hyperfiltration and retinovascular abnormalities was investigated in 43 black and 45 white children with essential hypertension. Whilst 36% of subjects had left ventricular hypertrophy, 49% had glomerular hyperfiltration and 50% had retinal abnormalities, no differences were found between blacks and whites. This pattern differs from that found in adult hypertensives.

Adolescent

Continuous hemodiafiltration in children.

Continuous arteriovenous hemofiltration is a form of renal replacement therapy whereby small molecular weight solutes and water are removed from the blood via convection, alleviating fluid overload and, to a degree, azotemia. It has been used in many adults and several children. However, in patients with multisystem organ dysfunction and acute renal failure, continuous arteriovenous hemofiltration alone may not be sufficient for control of azotemia; intermittent hemodialysis or peritoneal dialysis may be undesirable in such unstable patients. Recently, the technique of continuous arteriovenous hemodiafiltration has been used in many severely ill adults. We have used continuous arteriovenous hemodiafiltration in four patients at Children's Hospital Medical Center. Patient 1 suffered perinatal asphyxia and oliguria while on extracorporeal membrane oxygenation. Patients 2 and 4 both had Burkitt lymphoma and tumor lysis syndrome. Patient 3 had septic shock several months after a bone marrow transplant. All had acute renal failure and contraindications to hemodialysis or peritoneal dialysis. A blood pump was used in three of the four patients, while spontaneous arterial flow was adequate in one. Continuous arteriovenous hemodiafiltration was performed for varying lengths of time, from 11 hours to 7 days. No patient had worsening of cardiovascular status or required increased pressor support during continuous arteriovenous hemodiafiltration. The two survivors (patients 2 and 4) eventually recovered normal renal function. Continuous arteriovenous hemodiafiltration is a safe and effective means of renal replacement therapy in the critically ill child. It may be ideal for control of the metabolic and electrolyte abnormalities of the tumor lysis syndrome.

Acute Kidney Injury

Serum terminal complement component levels in hypocomplementemic glomerulonephritides.

Measurements of serum C3 through C9 are reported for patients with acute poststreptococcal glomerulonephritis (AGN), membranoproliferative glomerulonephritis type I (MPGN I), MPGN II, and MPGN III. Except in MPGN II, depressed C5 levels correlated with depressed C3 levels. In MPGN II, levels of C5 and of other terminal components were normal. In MPGN III, markedly depressed levels of C7 through C9 correlated strongly with depressed levels of C3 and C5. C6 was less severely depressed. In MPGN I, terminal component levels were less often depressed than in MPGN III and in AGN, depression of terminal components was seen only when levels of C3 and C5 were extremely low. The data indicate that late terminal components are activated in MPGN III to a greater extent than in the other nephritides despite C5 activation approximately equal in extent to that in AGN and MPGN I.

Acute Disease

A properdin dependent nephritic factor slowly activating C3, C5, and C9 in membranoproliferative glomerulonephritis, types I and III.

The IgG fraction of serum from patients with membranoproliferative glomerulonephritis (MPGN) types I and III was found to contain a nephritic factor (NFI/III) which differed from that usually present in MPGN type II and partial lipodystrophy (NFII) in that it converts C5 and C9 as well as C3, is dependent on properdin for its activity, and requires an incubation period of several hours rather than 30 min for its demonstration. C3 conversion occurred in the absence of an intact classical pathway. This nephritic factor was found in patients with reduced serum levels of terminal components and its activity, like that of the nephritic factor in MPGN type II, correlated with the serum C3 level indicating that these nephritic factors play a large role in producing hypocomplementemia. Although potentially nephritogenic because of its ability to activate the terminal pathway, the presence of this nephritic factor did not clearly correlate with clinical course.

Complement Activation

Antibody to a cryptic, solid phase C1Q antigen in membranoproliferative nephritis.

IgG containing material detected in membranoproliferative nephritis (MPGN) serum with a solid phase (sp) Clq ELISA has been presumed to be immune complexes. However, in serum from 13 MPGN patients containing large amounts of spClq-binding material, sucrose density ultracentrifugation and sieve chromatography showed spClq-binding protein to sediment at 7S or cofractionate with IgG. One serum (stored for 12 years) contained, in addition, spClq-binding material sedimenting at more than 19S. Isolated MPGN IgG was shown to bind to spClq. SpClq-binding material could be totally removed from MPGN serum by absorption with BSA-anti-BSA immune precipitates, and by acid elution of the precipitates IgG binding to spClq could be recovered. F(ab')2, isolated from pepsin digested MPGN IgG, continued to bind spClq. Binding of MPGN IgG or F(ab')2 to spClq was not inhibited by 2 M NaCl. Incubation of MPGN serum with 125I Clq followed by sucrose density ultracentrifugation resulted in a peak of radioactivity at 11S, the sedimentation rate of Clq, giving evidence that material binding fluid phase Clq is not present. SpClq-binding IgG was detected in 54% of 68 MPGN patients. These results indicate that the 7S spClq-binding IgG represents antibody to a cryptic antigen revealed only when Clq fixes to a solid surface.

Antigen-Antibody Complex

Effect of calcitonin replacement therapy in idiopathic juvenile osteoporosis.

An 8-year-old boy with idiopathic juvenile osteoporosis and multiple fractures had three abnormalities of bone mineral metabolism: calcitonin deficiency, elevated serum calcitriol concentrations, and hypercalciuria. Calcitonin deficiency was documented by two attempts to stimulate calcitonin secretion with intravenous calcium and pentagastrin. Treatment for 11 months with daily subcutaneous injections of human calcitonin and oral administration of calcitriol failed to reduce the excessive bone resorption observed on bone biopsy, and the fracture rate did not decrease. Treatment was discontinued for two months, then resumed with calcitonin injections and oral calcium supplementation. The fracture rate decreased but bone biopsy continued to show excessive resorption. Therapy was discontinued. After the onset of puberty, endogenous calcitonin was detectable. Exogenous calcitonin therapy may have failed to control bone resorption for several reasons: insufficient dose, reduction of bone receptors from long-term calcitonin exposure, secondary hyperparathyroidism, or lack of association between calcitonin deficiency and the bone disease.

Bone and Bones

Differences between membranoproliferative glomerulonephritis types I and III in clinical presentation, glomerular morphology, and complement perturbation.

Data for 26 patients with membranoproliferative glomerulonephritis, type I (MPGN I) and 22 with membranoproliferative glomerulonephritis, type III (MPGN III), as distinguished by glomerular ultrastructure, were analyzed to determine differences in presentation, complement perturbation, and glomerular morphology by light microscopy. MPGN III was detected with greater frequency by the chance discovery of hematuria and proteinuria in the otherwise healthy individual (MPGN III, 63%; MPGN I, 30%; P = .01) and never, in the absence of renal failure, presented with systemic symptoms such as ease of fatigue, weight loss, and pallor, as may patients with MPGN I. The more frequent detection of MPGN III by chance is evidence that its onset is insidious and that for long periods it produces no symptoms or signs. Glomerular proliferation is also less than in MPGN I. Further, in MPGN III, the complement perturbation and glomerular immunofluorescence give no evidence of classical pathway activation, for which there is abundant evidence in MPGN I. Even with severe hypocomplementemia in MPGN III, C3 nephritic factor, another cause of hypocomplementemia, is rarely detectable and then in very low concentration. The cause of the complement perturbation in MPGN III has so far escaped identification. Although these observations give evidence that MPGN III is distinct from MPGN I, there is compelling evidence from other studies that a predisposition to both types is inherited and that similar genetic factors are operative in the two types. Because their genetic basis appears to be the same, it must be concluded that despite their differences, types I and III are variants of the same disease.

Complement C3

Improved growth of three uremic children by nocturnal nasogastric feedings.

Three children with high-output renal insufficiency (estimated creatinine clearance, 20 to 25 mL/min/1.73 sq m) and linear and ponderal growth retardation were administered nocturnal nasogastric (NG) feedings at home by trained parents. The NG feedings were initiated at 50 kcal/kg/night and increased as needed to establish and maintain weight gain. Nocturnal feedings were continued for 13.5, 16, and 11 months, respectively. Improved caloric intake reestablished the velocity of weight gain from less than 5% to greater than 95% in each patient. Linear growth velocity improved from less than 5% in two patients and 40% in one patient to greater than 95% in two patients and 80% in the third patient. No change was observed in serum creatinine, electrolyte, calcium, or phosphorus levels. The serum urea nitrogen level remained below 100 mg/dl. Ensuring adequate caloric intake by nocturnal NG feedings, in addition to standard therapy, improved both ponderal and linear growth velocity.

Enteral Nutrition

Effect of the nephrotic syndrome on the concentration of serum complement components.

The concentration of 12 component and four control proteins of the complement system was measured in serum from 43 children with a nephrotic syndrome, which subsequently proved to be steroid-responsive, and from 13 children with focal glomerulosclerosis (FGS) and was compared with values from 197 normal subjects. Of classical pathway complement components, 40% of patients had low C1q levels and 20%, low C2 levels. Mean serum levels of C1s, C4, C1INH, and C4bp were elevated. Of alternative pathway components, factors B and I were low in one third, while levels of C3 and H were commonly elevated. Of the terminal components, only C8 and C9 were low. In five patients with FGS with hypoalbuminemia without edema, all component levels were normal. With the exception of C1q, C1s, and C8, high molecular weight (mol wt) components were in high concentration and low mol wt components in low concentration. The three exceptions may be explained by the subunit structure of C1 and C8. From a practical standpoint, the study indicates that edematous patients with a nephrotic syndrome may have low serum levels of C1q and C2, simulating classical pathway complement activation such as commonly occurs in glomerulonephritis. However, low levels of C4, and possibly C1s, can be used as indicators of classical pathway activation since their levels are not reduced by a nephrotic syndrome.

Adolescent