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Biomedical subjects

J H Vargas

Publications and source records attributed to J H Vargas.

At least 19 recordsLinked to original sources
PubMed2000

Profile of anemia in children after liver transplantation.

BACKGROUND: Clinical and hematological profile of chronic anemia in children after orthotopic liver transplantation (OLT) is unknown. METHODS: We prospectively studied children after orthotopic liver transplantation (OLT) with hemoglobin levels < 2 standard deviation of age appropriate mean for > 6 months. Investigations included hemogram, reticulocyte count, peripheral blood smear, serum vitamin B-12, folic acid levels, iron studies, Coomb's tests, serum erythropoietin (EPO) levels, and stool and urine tests for occult blood. RESULTS: Fifty-six participants (22 male and 34 female, mean age 82.9 months, range 20-232, mean post-OLT duration 48.8 months, range 6-132) were studied. The causes of anemia were idiopathic (32), iron deficiency (4), viral infections (2, HIV=1, parvovirus=1), and lymphoproliferative disease (2). Fifteen participants showed spontaneous recovery within 1-6 months. Thirty-one children with idiopathic anemia had low or normal EPO levels (mean 7.33 mmicro/L, range <2.5 to 15.9, normal 4-24). When outliers (iron deficiency=4, HIV disease= 1) were excluded, there was no statistical correlation between hematocrits and EPO levels. Serum vitamin B-12 levels (n=52) were elevated (normal 110-930 pg/ml) (mean=1,186 pg/ml) in 32 (61.5%) and were significantly higher in those with abnormal liver function tests. CONCLUSION: Anemia is a common problem in children after OLT. More than half the participants had anemia of unknown etiology with an inappropriate EPO response for the degree of anemia. The normal negative correlation between hematocrit and EPO was lost in these children. The observation regarding serum vitamin B-12 levels requires further study.

Adolescent↗
PubMed2000

The effect of immunosuppression on posttransplant lymphoproliferative disease in pediatric liver transplant patients.

BACKGROUND: Posttransplant lymphoproliferative disease (PTLD) is a serious complication associated with the use of chronic immunosuppression for solid organ transplantation. This study represents a retrospective analysis of UCLA's experience with PTLD in all pediatric liver transplant recipients between 1984-1997. We assessed the clinical presentation, risk factors, incidence density, immunological characteristics, management, and outcome of patients who developed PTLD when receiving either primary cyclosporin A (CsA) or tacrolimus. METHODS: A total of 251 children received primary CsA therapy of which 70 required OKT3 for steroid resistant rejection and 29 required tacrolimus rescue for OKT3 resistance and/or chronic rejection. One hundred forty one children received tacrolimus as primary therapy. Sixty patients who survived for less than 6 months after transplantation were excluded from the study. RESULTS: The total incidence density (ID) rate of PTLD was 1.8+/-0.4 per 100 patient-years (30/392). The overall ID rate of PTLD in the CsA group was 0.93+/-0.2 per 100 patient-years (15/251). Within this group of primary CsA-treated patients, the ID rate of PTLD was 0.49+/-0.1 without OKT3 or tacrolimus, 0.67+/-0.2 with OKT3, and 6.42+/-1.1 with tacrolimus rescue. The overall PTLD ID rate in the primary tacrolimus-treated patients was 4.86+/-1.2 per 100 person-years (15/141). There was a 5-fold increase in the ID rate of PTLD in the primary tacrolimus group when compared to the comparable, primary CsA group (P<0.001). The mean time to PTLD was 5-fold longer (49.7+/-20.7 months) in the CsA group when compared to the CsA/tacrolimus rescue group (9.8+/-3 months, P<0.05) or the tacrolimus primary group (12.6+/-5.1 months, P<0.05). Five patients had monoclonal disease in the CsA group, but only one in the tacrolimus group (P<0.05). Clinical presentations with enlarged lymph nodes, fevers, malaise, anorexia, weight loss, hypoalbuminemia, and gastrointestinal blood loss were common. Mortality was 20%, three patients died in each group. CONCLUSION: The use of primary tacrolimus therapy was associated with a significant 5-fold higher rate of PTLD when compared to those treated with primary cyclosporine. Early diagnosis, decrease and/or discontinuation of potent immunosuppressive agents may contribute to decrease morbidity and mortality of this entity.

Adolescent↗
PubMed2000

Does liver transplantation affect growth pattern in Alagille syndrome?

Alagille syndrome (AGS) is frequently associated with growth failure, which has been attributed to concurrent congenital anomalies, cholestasis, and malabsorption and/or malnutrition. However, the underlying cause of the growth failure is not well understood. Our objective is to analyze the growth pattern in 26 patients with AGS and the possible effect that orthotopic liver transplantation (OLT) may have on this pattern. The standardized height, weight, and growth velocity of 26 pair-matched patients with AGS were compared. Thirteen patients underwent OLT. Repeated-measure ANOVA methods were used for the statistical analysis. The overall mean standardized height (z score) was -2.92 in the OLT group versus -1.88 in the non-OLT group (P =.03). The overall mean standardized weight was -1. 21 in the non-OLT group and -1.67 in the OLT group (P =.23). In 15 patients, birth weight was 2.82 +/- 0.4 kg, for a mean standardized weight of -0.95, and weight at diagnosis was 4.53 +/- 2.12 kg, for a mean standardized weight of -1.56. Bone age was delayed in the 9 patients who underwent bone-age analysis. Growth hormone therapy administered to 2 patients did not improve growth. Patients with AGS had growth failure secondary to other factors in addition to liver disease. Growth failure beginning in the prenatal period supports a genetic basis for this feature. Growth improvement up to normal levels should not be expected as a benefit of OLT in these patients. Growth failure as a primary indication for OLT should be cautiously examined in patients with AGS.

Age Determination by Skeleton↗
PubMed2000

Rapidly destructive hip disease: a case report and review of the literature.

Rapidly destructive hip disease (RDHD) is an arthropathy of unknown cause that involves rapid and total deterioration of both the acetabular and femoral aspects of the hip joint. We report a case in which radiographs taken 6 weeks apart vividly and poignantly demonstrate the rapidity of the disease. Because there is little in the orthopedic literature regarding RDHD, we would like orthopedic surgeons to be aware of the condition and the importance of repeat radiographs for patients with continued severe hip pain without an apparent cause.

Acetabulum↗
PubMed1999

Factors affecting growth after pediatric liver transplantation.

BACKGROUND: Poor linear growth after pediatric orthotopic liver transplantation (OLT) is a well-described phenomenon. We have undertaken a bivariate and multivariate analysis of multiple factors that might effect postOLT growth in all children who underwent transplantation at a single center, with survival > 1 year and adequate follow-up. METHODS: Standardized height score (Z score) and height deficit (centimeters below the 50th percentile) were computed for each patient over time. The variables assessed were (i) age at OLT, (ii) gender, (iii) pretransplantation diagnosis, (iv) Z score and height deficit at OLT, (v) tacrolimus versus cyclosporine as primary immunosuppressive therapy, (vi) retransplantation, (vii) graft disease, (viii) chronic illness, (ix) posttransplant lymphoproliferative disease, (x) intractable rejection, and (xi) prednisone withdrawal. RESULTS: A total of 236 children met the inclusion criteria, with a mean follow-up of 3.8+/-1.9 years. For the population as a whole, the baseline Z score was -1.72 (fourth percentile) with a significant improvement to - 1.37 (ninth percentile) at 2 years, but with no additional gain at 5 years (Z score -1.4). The baseline height deficit was -6.4 cm, with no improvement at 2 years (-6.52 cm), and was significantly worse at 5 years (-7.87 cm). In the bivariate analysis, the most important variables affecting growth were age at OLT, Z score at OLT, and diagnosis. In general, children <2 years with biliary atresia and those with the most growth delay at OLT showed the best posttransplantation growth. In the multivariate analysis, 18 factors were considered, of which 9 were significant. These were (i) Z score at baseline, (ii) follow-up time, (iii) age at OLT, (iv) diagnosis of tumor, (v) diagnosis of fulminant hepatic failure, (vi) retransplantation, (vii) graft disease, (viii) posttransplant lymphoproliferative disease, and (ix) stoppage of prednisone. Multivariate models using these nine variables accounted for 84% of the variation in standardized height. CONCLUSION: In general, children after OLT show some potential for catch-up growth but do not achieve normal height compared with their age and sex-matched peers. A multivariate analysis was necessary to investigate the interdependent effects of the many variables that can affect growth after OLT. The most important detrimental affects were older age at time of OLT, Z scores greater than -2.0 at OLT, fulminant hepatic failure, tumor, and postOLT complications causing graft dysfunction.

Adolescent↗
PubMed1999

The involvement of the gastrointestinal tract in posttransplant lymphoproliferative disease in pediatric liver transplantation.

BACKGROUND: Posttransplant lymphoproliferative disease (PTLD) is a serious complication associated with the use of immunosuppression after transplantation. In a retrospective study the clinical features of PTLD located primarily in the gastrointestinal tract were analyzed. METHODS: Three hundred ninety-two consecutive pediatric patients who underwent orthotopic liver transplantation (OLT) during a 13-year period with a survival of more than 6 months were reviewed. Two immunosuppression protocols were used: cyclosporin A, or tacrolimus-based primary therapy. Twenty-nine randomly selected liver transplant recipients without PTLD were used for comparison of signs and symptoms of gastrointestinal PTLD. RESULTS: Among the 30 patients identified with PTLD, 9 had gastrointestinal PTLD. The overall incidence density of PTLD was 1.8 per 100 patient-years (30/392). Nine patients (30%) had involvement of the gastrointestinal tract, whereas 7 (23%) had the gastrointestinal tract as the only involved site. When compared with a cohort of liver transplant recipients without PTLD, only gastrointestinal bleeding, weight loss, hypoalbuminemia, and protein-losing enteropathy were signs most likely associated with gastrointestinal PTLD. Hypoalbuminemia was the most sensitive sign of gastrointestinal PTLD. The lower tract (ileum and colon) was the most common site of involvement. CONCLUSIONS: gastrointestinal involvement is common and occurs in 30% of all patients with PTLD. It may be the only affected organ in a subgroup of patients. Hypoalbuminemia, gastrointestinal bleeding, and weight loss are features that are characteristic of gastrointestinal PTLD. Patients with aggressive gastrointestinal signs and symptoms should undergo upper and lower gastrointestinal tract endoscopy with biopsy, to establish the diagnosis.

Adolescent↗
PubMed1999

Variable morbidity in alagille syndrome: a review of 43 cases.

BACKGROUND: Alagille syndrome is one of the most common inherited disorders that cause chronic liver disease in children. Early reports suggested a benign course in these patients. Subsequent reports showed significant morbidity and mortality. This study was designed to analyze the long-term clinical course in Alagille syndrome. METHODS: The records of children with Alagille syndrome seen during a 20-year period were reviewed. RESULTS: Forty-three patients were identified. Liver disease was diagnosed before 12 months of age in 95%. The frequencies of renal anomalies (50%) and intracranial hemorrhage (12%) were significant. The high incidence of chronic otitis media (35%) has not been reported previously. One patient had a renal transplant. Vascular compromise as a pathologic mechanism for some characteristics of the syndrome is also suggested by the presence of small bowel stenosis and atresia, tracheal and bronchial stenosis, renal artery stenosis, middle aortic syndrome, and avascular necrosis of the humeral and femoral heads. Twenty (47%) patients underwent liver transplantation. Five of six who underwent Kasai procedure required liver transplantation. Twelve died (28%), five after liver transplantation. One patient died of intracranial bleeding. Sixteen (37%) without liver transplantation and 15 (35%) who underwent liver transplantation are alive. CONCLUSIONS: Some patients with early-onset and more severe liver disease can benefit from liver transplantation. Careful and complete assessment should be made of infants with a cholestatic syndrome, to avoid misdiagnosis and unnecessary Kasai procedures. Our observation of vascular compromise in various organ systems suggests that notch signaling pathway defects affect angiogenesis in Alagille syndrome.

Adolescent↗
PubMed1998

Prevention and preemptive therapy of postransplant lymphoproliferative disease in pediatric liver recipients.

BACKGROUND: We have previously reported a 10% incidence of posttransplant lymphoproliferative disease (PTLD) in pediatric patients receiving first liver grafts and primarily immunosuppressed with tacrolimus. To decrease the incidence of PTLD, we developed a protocol utilizing preemptive intravenous ganciclovir in high-risk recipients (i.e., donor (D)+, recipient (R)-), combined with serial monitoring of peripheral blood for Epstein Barr virus (EBV) by polymerase chain reaction (PCR). METHODS: Consecutive pediatric recipients of a first liver graft were immunosuppressed with oral tacrolimus (both induction and maintenance), and low-dose prednisone. EBV serologies were obtained at the time of orthotopic liver transplant in recipients and donors. Recipients were divided into groups: group 1, high-risk (D+R-), and group 2, low-risk (D+R+; D-R-; D-R+). In group 1 (high-risk), all patients received a minimum of 100 days of intravenous ganciclovir (6-10 mg/kg/day), while, in group 2 (low-risk), patients received intravenous ganciclovir during their initial hospitalization and then were converted to oral acyclovir (40 mg/kg/day) at discharge. Semiquantitative EBV-PCR determinations were made at 1-2-month intervals. In both groups, patients with an increasing viral copy number by EBV-PCR had tacrolimus levels decreased to 2-5 ng/ml. Tacrolimus was stopped, and intravenous ganciclovir reinstituted for PTLD. A positive EBV-PCR with symptoms, but negative histology, was defined as EBV disease; PTLD was defined as histologic evidence of polyclonal or monoclonal B cell proliferation. RESULTS: Forty children who had survived greater than 2 months were enrolled. There were 18 children in group 1 (high-risk; mean age of 14+/-15 months and mean follow-up time of 243+/-149 days) and 22 children in group 2 (low-risk; mean age of 64+/-65 months and follow-up time of 275+/-130 days). In group 1 (high-risk), there was no PTLD and one case of EBV disease (mononucleosis-like syndrome), which resolved. In group 2 (low-risk), there were two cases of PTLD; both resolved when tacrolimus was stopped. Both children were 8 months old at time of transplant. Neither received OKT3, and they had one and two episodes of steroid-sensitive rejection, respectively. One child had EBV disease (mild hepatitis), which resolved. CONCLUSIONS: Since instituting this protocol, the overall incidence of PTLD has fallen from 10% to 5% for children receiving primary tacrolimus therapy after OLT. No high-risk pediatric liver recipient treated preemptively with intravenous ganciclovir developed PTLD. Both children with PTLD were less than 1 year at OLT and considered low-risk. However, their positive EBV antibody titers may have been maternal in origin and not have offered long-term protection. Serial monitoring of EBV-PCR after pediatric OLT is recommended to decrease the risk of PTLD by allowing early detection of EBV infection, which is then managed by decreasing immunosuppression and continuing intravenous ganciclovir.

Antiviral Agents↗
PubMed1996

Chronic liver disease in children on long-term parenteral nutrition.

Use of long-term total parenteral nutrition (TPN) is often presumed to be associated with serious hepatic dysfunction. In this retrospective study, we reviewed the complete charts of patients who had received TPN for more than 2.5 years, starting in infancy or childhood, for evidence of liver dysfunction. There were 16 male and 10 female patients with a total of 254.5 patient years on TPN. Seventeen patients have been on TPN since birth or early infancy. Thirteen of 26 patients derive > or = 90% of their calorie intake from TPN. Six patients had hepatomegaly; two of them also had splenomegaly. Twenty-one patients had normal transaminases, nine have had past episodes of raised enzymes ranging from 2.5 to 7.5 times normal. Seventeen patients always had normal bilirubin levels, five had past episodes of hyperbilirubinaemia, while four patients had persistently raised bilirubin levels (range 1.5-20.7 g/dl). Alkaline phosphatase was normal for age in all patients except two. Hepatic synthetic function, as measured by albumin, pre-albumin levels and prothrombin time, was within the normal range in all patients except one. Liver biopsies were performed in eight patients. Two biopsies showed cirrhosis, one showed chronic active hepatitis (CAH) with cholestasis, two patients had fibrosis, one showed cholestasis and two biopsies were normal. One patient with cirrhosis and one with CAH were positive for hepatitis C antibody. Another asymptomatic patient was positive for hepatitis B. Only the patient with CAH had hepatic decompensation. We conclude that clinical hepatic failure is uncommon in our group of patients on long-term TPN for 2.5 years or more. Cirrhosis and fibrosis, when found, could not be solely attributed to TPN.

Adolescent↗
PubMed1995

Overinterpretation of gastroduodenal motility studies: two cases involving Munchausen syndrome by proxy.

Two children were thought to have an atypical gastroduodenal motility disorder because of the history and clinical course; both had received parenteral alimentation because of claims of inability to tolerate enteral feedings, and both continued to have unusual medical problems during parenteral alimentation. Both children had motility studies that were interpreted by a pediatric gastroenterologist to be "abnormal" and "diagnostic" of a motility disorder, but each was eventually shown to have a behavioral abnormality related to Munchausen syndrome by proxy.

Child, Preschool↗
PubMed1994

Medical therapy for ulcerative colitis in childhood.

Corticosteroids remain the primary therapeutic agent to induce remission in moderate to severe ulcerative colitis (UC) and Crohn's disease because of their rapidity of action in comparison to other agents. Mild UC and/or Crohn's disease of the colon and terminal small bowel may be treated with azulfidine first. However, if patients are intolerant of these medications, dipentum or asacol may be used. Occasionally, patients with Crohn's colitis but not UC may respond to metronidazole. Immunosuppressive agents such as 6-mercaptopurine are very useful for steroid-dependent inflammatory bowel disease, as a substitute for long-term corticosteroids. Cyclosporine, although it has been proposed as an alternative to other antimetabolite or immunosuppressive therapy, is of benefit in fewer than 25% of cases of UC or Crohn's disease. Rowasa enemas are useful for left-sided disease in UC or Crohn's disease of the colon; however, use in children may be difficult in view of psychosocial issues that must be considered.

Adrenal Cortex Hormones↗
PubMed1992

OKT3 treatment of steroid-resistant rejection in pediatric liver transplant recipients.

Of a total of 187 consecutive liver grafts in 149 pediatric recipients, 59 episodes of steroid-resistant, biopsy-proven rejection (32% of grafts) were treated with OKT3 monoclonal antibody. After 59 OKT3-treated episodes, liver function at the end of treatment was normal in 40%, improved in 35%, and unchanged in 24%. Of 21 partial responses, 12 episodes eventually resolved to yield an overall complete response rate of 59%. CD3-positive T-cells greater than 5% occurred during 61% of OKT3-treated rejection episodes and was associated with impaired efficacy of OKT3 (30% complete response rate). Six grafts were re-treated with OKT3 for rejection and in all CD3-positive T-cells could not be maintained less than 5%. Of the six grafts requiring repeat OKT3, five failed-retreatment and required retransplantation. OKT3 antibodies of low titer were found prior to a second use of OKT3 in 65% of episodes. Patients treated with OKT3 after failing more than two preceding steroid courses had a significantly increased chance of graft loss (57%; p = 0.01). We conclude that this group of pediatric patients appeared less responsive to OKT3 compared to other series combining pediatric and adult recipients, possibly due to a more vigorous immune response in the child.

Antibodies↗