Early volume expansion during diarrhea and relative nephroprotection during subsequent hemolytic uremic syndrome

OBJECTIVES

To determine if interventions during the pre-hemolytic uremic syndrome (HUS) diarrhea phase are associated with maintenance of urine output during HUS.

DESIGN

Prospective observational cohort study.

SETTINGS

Eleven pediatric hospitals in the United States and Scotland.

PARTICIPANTS

Children younger than 18 years with diarrhea-associated HUS (hematocrit level <30% with smear evidence of intravascular erythrocyte destruction), thrombocytopenia (platelet count <150 × 10³/mm³), and impaired renal function (serum creatinine concentration > upper limit of reference range for age).

INTERVENTIONS

Intravenous fluid was given within the first 4 days of the onset of diarrhea.

OUTCOME MEASURE

Presence or absence of oligoanuria (urine output ≤ 0.5 mL/kg/h for >1 day).

RESULTS

The overall oligoanuric rate of the 50 participants was 68%, but was 84% among those who received no intravenous fluids in the first 4 days of illness. The relative risk of oligoanuria when fluids were not given in this interval was 1.6 (95% confidence interval, 1.1-2.4; P = .02). Children with oligoanuric HUS were given less total intravenous fluid (r = -0.32; P = .02) and sodium (r = -0.27; P = .05) in the first 4 days of illness than those without oligoanuria. In multivariable analysis, the most significant covariate was volume infused, but volume and sodium strongly covaried.

CONCLUSIONS

Intravenous volume expansion is an underused intervention that could decrease the frequency of oligoanuric renal failure in patients at risk of HUS.

Deer sausage: a newly identified vehicle of transmission of Escherichia coli O157:H7

Five Missouri patients infected with Escherichia coli O157:H7 were studied for an epidemiologically plausible association. Case isolates, case interviews, and pathogen and meat XbaI pulsed field electrophoresis patterns were consistent with the common source being contaminated, fermented deer sausage, a previously unrecognized mode of transmission for Escherichia coli O157:H7.

Mutations of the SBDS gene are present in most patients with Shwachman-Diamond syndrome

Shwachman-Diamond Syndrome (SDS) is a rare multisystem disorder characterized by exocrine pancreatic insufficiency, bone marrow dysfunction, and metaphyseal chondrodysplasia. Recent studies show that mutations of SBDS, a gene of unknown function, are present in the majority of patients with SDS. In the present study, we show that most, but not all, patients classified based on rigorous clinical criteria as having SDS had compound heterozygous mutations of SBDS. Full-length SBDS protein was not detected in leukocytes of SDS patients with the most common SBDS mutations, consistent with a loss-of-function mechanism. In contrast, SBDS protein was expressed at normal levels in SDS patients without SBDS mutations. These data confirm the absence of SBDS mutations in this subgroup of patients and suggest that SDS is a genetically heterogeneous disorder. The presence (or absence) of SBDS mutations may define subgroups of patients with SDS who share distinct clinical features or natural history.

Bone marrow failure in Shwachman-Diamond syndrome does not select for clonal haematopoiesis of the paroxysmal nocturnal haemoglobinuria phenotype

Bone marrow failure is believed to be the underlying condition that drives the expansion of the paroxysmal nocturnal haemoglobinuria (PNH) clone. Indeed, circulating PNH blood cells have been identified in patients with acquired aplastic anaemia and with hypoplastic myelodysplasia. Whether PNH blood cells are also present in patients with inherited aplastic anaemia has not been reported. We screened a large group of patients diagnosed with Shwachman-Diamond Syndrome (SDS) for PNH blood cells. None of the patients analysed had detectable circulating PNH blood cells, indicating that bone marrow failure in SDS does not select for PNH progenitor cells.

Similarities in cyclic vomiting syndrome across age groups

OBJECTIVE

Cyclic vomiting syndrome is well recognized in children yet has poorly defined pathogenesis and treatment. Cyclic vomiting syndrome is occasionally diagnosed in older subjects, but little attempt has been made to determine if such cases represent a unique disorder.

METHODS

We reviewed clinical data from 39 patients aged 1.8-75 yr with cyclic vomiting syndrome meeting published criteria for diagnosis. Clinical characteristics were compared between subjects with symptom onset in childhood (<12 yr, n = 18) and subjects with onset at an older age (> or =12 yr, n = 21; mean age at onset 34.8+/-3.8 yr).

RESULTS

All patients had stereotypical episodes of vomiting separated by varying symptom-free intervals. The prevalence rates of prodromal symptoms, triggering events, alleviants, associated symptoms including abdominal pain and diarrhea, and past or family history of migraine were similar in the children and older subjects with the syndrome (p > 0.3 for each). Delay in diagnosis was greater in the older subset (3.1+/-0.8 yr vs 7.9+/-3.1 yr, p < 0.05). Interepisode intervals and total number of hospitalizations did not differ significantly between younger and older patients, but duration of episodes was significantly longer in the older group (2.0+/-0.5 days vs 3.8+/-0.4 days, p < 0.01). When subjects were further substratified by age of illness onset, duration of episodes progressively increased from infant/toddlers (1.8+/-0.4 days) through childhood (2.3+/-0.5 days) and adolescence (2.9+/-1.0 days) and into adulthood (3.9+/-0.5; p < 0.05 across groups). Episode duration did not lengthen further in subgroups >20 yr of age.

CONCLUSIONS

Many characteristics of cyclic vomiting syndrome are similar irrespective of age at disorder onset, suggesting a uniform pathogenesis. Duration of episodes increases with age to age 20 yr. Increased awareness of the condition and a high index of suspicion may help decrease delay in diagnosis after symptom onset.

Cystic fibrosis: CT findings of colonic disease

PURPOSE

To determine the computed tomographic (CT) findings that are indicative of bowel disease in patients with cystic fibrosis.

MATERIALS AND METHODS

CT scans in patients with cystic fibrosis were retrospectively reviewed for evidence of colonic abnormalities, including wall thickening, mural striation, fatty proliferation of the mesentery, and soft-tissue infiltration of pericolonic fat.

RESULTS

Ten patients with colonic abnormalities on CT scans (case patients) and 16 patients with normal CT results (cohort patients) were identified. Colonic abnormalities in case patients included wall thickening (mean thickness, 6.4 mm) and mesenteric infiltration in all, increased pericolonic fat in six, and mural striation in five. The right colon was involved in all case patients; contiguous extension involved the transverse colon in five, the descending colon in two, and all segments in one. Wall thickness in cohort patients was less than 2 mm. Eight case patients had abdominal pain; one had bloody diarrhea. Histopathologic examination results included nonspecific mucosal inflammation in four case patients, wall edema in one, and no abnormality in one. No patient had identifiable infectious colitis, colonic stricture, bowel obstruction, fibrosis, or Crohn disease. Mean dose of pancreatic enzyme replacement was similar in both groups.

CONCLUSION

Proximal colonic wall thickening without stricture, pericolonic fat proliferation, and mesenteric infiltration are CT findings of colonic disease associated with cystic fibrosis.

Complications of pediatric endoscopy

In pediatric patients, UGI endoscopy and colonoscopy may provide essential information for diagnosis and management. Diagnostic endoscopic procedures generally are safe with a rate of less than 1% of serious complications. Therapeutic procedures carry higher rates of complications, but usually are also accomplished without problems. The rarity of complications creates a unique situation: many endoscopists encounter problems infrequently. Their personal experience is limited. When evaluating a patient for a potentially serious complication, the endoscopist struggles with maintaining objectivity and clear judgment. The responsible physician re-examines and re-evaluates the preceding events: Were risks explained clearly? Were correct decisions made during the procedure? Were early problems overlooked? Simultaneously, the physician endeavors to discern the seriousness of the patient's apparent problem and to design appropriate intervention. Dealing with these multiple issues may impair decision-making. In these trying situations, experienced colleagues and consultants can provide invaluable advice and counsel. Each physician must recognize situations in which soliciting help represents a critical initial step in the process of correcting or treating the complication. Optimal patient care results from review of the procedural details, assessment of the patient's current status, discussion of potential interventions, and evaluation of the effectiveness of interventions with trusted and experienced colleagues. The knowledge of who and when to call for support and guidance provides a final measure of insurance for minimizing the risk of procedure-related complications.

Multicenter trial of d-alpha-tocopheryl polyethylene glycol 1000 succinate for treatment of vitamin E deficiency in children with chronic cholestasis

BACKGROUND

Malabsorption and deficiency of vitamin E causing neurological degeneration are common consequences of chronic childhood cholestatic liver disease. The objective of this study was to determine the long-term efficacy and safety of d-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS) in correcting vitamin E deficiency in children with chronic cholestasis who were unresponsive to other forms of oral vitamin E.

METHODS

Sixty vitamin E-deficient children with chronic cholestasis unresponsive to 70-212 IU.kg-1.day-1 of oral vitamin E were entered into a trial at eight centers in the United States. After initial evaluation, treatment was started with 25 IU.kg-1.day-1 of TPGS. Vitamin E status, neurological function quantitated by a specific scoring system, and clinical and biochemical parameters were monitored during therapy.

RESULTS

All children responded to TPGS with normalization of vitamin E status. Neurological function, which had deteriorated before entry in the trial, improved in 25 patients, stabilized in 27, and worsened in only 2 after a mean of 2.5 years of therapy. No adverse effects were observed.

CONCLUSIONS

TPGS (20-25 IU.kg-1.day-1) appears to be a safe and effective form of vitamin E for reversing or preventing vitamin E deficiency during chronic childhood cholestasis.

Granulomatous hepatitis associated with cat scratch disease

In three patients with cat scratch disease the liver was affected. All three had high fever (39 degrees C) for more than 3 weeks. Two of them had no peripheral adenopathy. Computed tomography of the abdomen revealed focal hepatic defects in two patients and periportal and periaortic adenopathy in the third. At laparotomy, there were nodules on the liver surfaces of all patients and histological examination revealed necrotising granulomata. The Warthin-Starry silver stain showed organisms consistent in appearance with the cat scratch bacillus in the liver and a periaortic lymph node of one patient, in the liver of the second patient, and in the axillary lymph node of the third. In all three patients the clinical findings and radiological abnormalities improved without specific therapy. A review of the surgical pathology files of Washington University revealed only two other cases of granulomatous hepatitis in children over a 6-year period. These findings indicate that cat scratch disease should now be included in the differential diagnosis of granulomatous hepatitis, at least in children. The absence of peripheral adenopathy in two of the three patients with granulomatous hepatitis suggests that the clinical spectrum of cat scratch disease may be broader than previously appreciated.

Grade I Reye's syndrome. A frequent cause of vomiting and liver dysfunction after varicella and upper-respiratory-tract infection

In a one-year prospective study we assessed the incidence of Reye's syndrome in children presenting with the acute onset of vomiting after a prodromal upper-respiratory-tract infection or varicella, and with serum alanine or aspartate aminotransferase levels at least three times higher than normal, and a paucity of neurologic findings. Of 25 patients meeting the above criteria, 19 had liver biopsies yielding adequate tissue for diagnostic purposes. Biopsy specimens from 14 of these 19 patients (74 per cent) were diagnostic of Reye's syndrome, according to rigorous light-microscopical, histochemical, and ultrastructural criteria. None of the biopsy specimens contained evidence of other acute pathologic processes, including hepatitis. A wide spectrum of mitochondrial alterations existed at the ultrastructural level, ranging from mild to severe lesions that were indistinguishable from those seen in comatose patients with Reye's syndrome. Our findings suggest that the clinical complex of vomiting, hepatic dysfunction, and minimal neurologic impairment after varicella or an upper-respiratory-tract infection usually represents Reye's syndrome. This syndrome occurs more frequently than previously recognized.

An ultrastructural study of enteropathogenic Escherichia coli infection in human infants

Over the past 2 years, we have studied and treated 18 infants with protracted diarrhea due to an enteropathogenic Escherichia coli serogroup 0119. All patients had persistent stool escretion and jejunal over-growth with this pathogenic E. coli. Jejunal biopsy revealed atrophy of villi with a chronic inflammatory cell infiltrate in the lamina propria. E. coli 0119 adhered to the luminal surface of enterocytes. Electron microscopy showed disappearance of glycocalyx and microvilli at the areas of bacterial adherence. Intracellular damage was indicated by dilatation of rough endoplasmic reticulum, mitochondrial changes, and cytoplasmic pallor. Similar changes in histology and ultrastructure occurred in ileal epithelial cells. Glandular crypt epithelium showed prominent subnuclear vacuolation and separation of lateral intercellular junctions throughout the small intestine. Rectal mucosal biopsy showed mucus depletion and irregular atrophy of the epithelium, with E. coli 0119 adherent to the luminal surface. Ultrastructural damage paralleled that in the small intestine. E. coli 0119 causes damage to epithelial cells throughout the infant intestinal tract. This damage leads to atrophy of villi and a marked reduction in absorptive surface area, resulting in protracted diarrhea.

Unusual surface distribution of concanavalin A reflects a cytoskeletal defect in neutrophils in Shwachman's syndrome

Schwachman's syndrome is characterised by pancreatic insufficiency and frequent infections. Absolute polymorphonuclear leucocyte (PMN) counts are low in many patients, and the PMN show abnormal chemotaxis. It was postulated that a cytoskeletal defect might underlie these abnormalities, and a cytoskeleton-dependent function, the surface distribution and mobility of concanavalin-A receptors, was studied on neutrophils from Schwachman's syndrome patients. Approximately a third of the neutrophils in each patient showed a patched distribution of fluorescein-conjugated concanavalin A (FITC-con A) rather than the usual diffuse staining pattern. These patched neutrophils also bound larger amounts of FITC-con A than diffusely stained or capped PMN from the same patient. Antitubulin treatment did not alter the proportion of patched PMN. These findings suggest that a cytoskeletal defect underlies the patching of FITC-con A on the PMN surface. This defect could also contribute to the abnormal chemotaxis and frequent infections found in Shwachman's syndrome patients.

Serum alkaline phosphatase and zinc undernutrition in infants with chronic diarrhea

III infants and children need zinc replacement in total parenteral nutrition solutions, but assessment of these needs and total body zinc status is difficult. Seven infants with severe diarrhea initially given 80 to 100 micrograms/kg/day of elemental zinc developed systemic zinc deficiency as indicated by an acrodermatitis-like skin rash and low serum alkaline phosphatase. Serum zinc levels were borderline low only in conjunction with hypoalbuminemia. Daily urinary zinc excretion was normal. With increased zinc supplementation of 200 to 300 micrograms/kg/day, the rash healed and serum alkaline phosphatase rose to normal levels for age. The activity of the metalloenzyme alkaline phosphatase accurately reflects total body zinc status in infants. With diarrheal illness, infants, need high doses zinc supplementation to replace considerable stool losses.