Drora Berkowitz

The deoxyguanosine kinase gene is mutated in individuals with depleted hepatocerebral mitochondrial DNA.

Mitochondrial DNA (mtDNA)–depletion syndromes (MDS; OMIM 251880) are phenotypically heterogeneous, autosomal-recessive disorders characterized by tissue-specific reduction in mtDNA copy number. Affected individuals with the hepatocerebral form of MDS have early progressive liver failure and neurological abnormalities, hypoglycemia and increased lactate in body fluids. Affected tissues show both decreased activity of the mtDNA-encoded respiratory chain complexes (I, III, IV, V) and mtDNA depletion. We used homozygosity mapping in three kindreds of Druze origin to map the gene causing hepatocerebral MDS to a region of 6.1 cM on chromosome 2p13, between markers D2S291 and D2S2116. This interval encompasses the gene (DGUOK) encoding the mitochondrial deoxyguanosine kinase (dGK). We identified a single-nucleotide deletion (204delA) within the coding region of DGUOK that segregates with the disease in the three kindreds studied. Western-blot analysis did not detect dGK protein in the liver of affected individuals. The main supply of deoxyribonucleotides (dNTPs) for mtDNA synthesis comes from the salvage pathway initiated by dGK and thymidine kinase-2 (TK2). The association of mtDNA depletion with mutated DGUOK suggests that the salvage-pathway enzymes are involved in the maintenance of balanced mitochondrial dNTP pools.

Progressive familial intrahepatic cholestasis among the Arab population in Israel.

BACKGROUND Progressive familial intrahepatic cholestasis, which constitutes a heterogeneous group of imperfectly delineated syndromes and appears to be inherited as an autosomal recessive condition, has not been hitherto reported from the Middle East, in spite of the high rate of consanguineous marriage in this region. METHODS Sixteen affected children from six Israeli Arab families were evaluated over 30 years. All were born to consanguineous parents. RESULTS Jaundice appeared during the first 3 weeks of life in 15 babies. When first referred, 10 had hepatomegaly and nine had splenomegaly. A progression toward cirrhosis was the rule. Serum levels of conjugated bilirubin, liver enzymes, and alkaline phosphatase were raised; gamma-glutamyl transpeptidase levels were normal in all three infants in whom it was examined, but elevated in two siblings of another family at ages 2 and 3 years. No abnormal bile acids were detected in the serum and urine of patients. Histologic examination of the liver showed giant-cell transformation, paucity of intrahepatic bile ducts, cholestasis, fibrosis, or cirrhosis. The pattern of liver pathology differed at times among affected members within the same family. Therapeutic trials with phenobarbital, cholestyramine, or ursodeoxycholic acid were ineffective. Survival of the patients was from 5 to 18 months in four families; in the other two families, three children received liver transplants, and one is awaiting liver transplantation. CONCLUSIONS Progressive familial intrahepatic cholestasis should be included in the differential diagnosis of infants with cholestatic jaundice of unknown etiology, especially those born to consanguineous Arab parents.

Prevalence and significance of mutations in the familial Mediterranean fever gene in patients with Crohn's disease.

The concurrence of Crohns disease (CD) and familial Mediterranean fever was repeatedly reported. In this study we determined the distribution and contribution of MEFV gene mutations to CD susceptibility and clinical heterogeneity. An Israeli cohort of 209 CD patients (120 men and 89 women) was investigated for mutations in the MEFV gene. A detailed chart review, interview and physical examination were used to determine sociodemographic and clinical characteristics. MEFV and NOD2/CARD15 genotypes were analyzed in all patients and a genotype–phenotype correlation analysis was undertaken. The results of this study do not implicate MEFV mutations as major modifiers in CD. However, the E148Q MEFV variant was associated with susceptibility to perianal disease. More specifically, 19% (9/47) of CD patients with perianal disease carried the E148Q mutation compared to 6.7% (11/162) of CD patients without perianal involvement (OR 3.26, 95% CI 1.2–8.8, P=0.02). Although, for all mutations taken together, the prevalence of MEFV gene mutations among CD patients and controls was similar, the hypothesis that E148Q mutation modulates the phenotypic expression of CD is corroborated by the results of this study and needs to be further evaluated.

Efficacy of bismuth-based triple therapy in children with abdominal pain and Helicobacter pylori gastritis.

BACKGROUND To evaluate the effect of a therapeutic regimen of 7 days versus 14 days on the clinical manifestations of Helicobacter pylori gastritis in children. METHODS Ninety children (age 2-19 years) who had abdominal pain and/or recurrent vomiting were determined to have H. pylori gastritis by endoscopy, histology, and a Giemsa stain positive for H. pylori. The patients were randomized to receive amoxicillin, metronidazole, and bismuth subcitrate for 7 days (group A; 45 children) or 14 days (group B; 45 children) and were observed clinically for 19 +/- 11.5 months. Resolution of all abdominal and gastrointestinal symptoms was considered a good response. RESULTS A good response was obtained in 36 (80%) children from group A, and in 37 (82%) from group B. A recurrence of symptoms occurred in four (11%) of the responders from group A, and in six (15.2%) from group B. CONCLUSIONS A 7-day course of bismuth-based triple therapy for H. pylori gastritis in children appears to be clinically as effective as a 14-day regimen. The feasibility of a shorter therapeutic regimen may enhance patient compliance and provide a better chance of clinical benefit.

Hypothyroidism and dyshormonogenesis induced by D-penicillamine in children with Wilson's disease and healthy infants born to a mother with Wilson's disease.

Two siblings born to a mother with Wilsons disease, who was taking D-penicillamine, developed transient goitrous hypothyroidism. A prospective evaluation of 5 patients with Wilsons disease taking and not taking D-penicillamine for as long as 9.5 years showed subclinical hypothyroidism. D-penicillamine probably inhibited thyroperoxidase activity in utero in healthy infants and during childhood in patients with Wilsons disease.

Increased Toll-like receptor 9 expression by B cells from inflammatory bowel disease patients.

BACKGROUND Toll-like receptors (TLRs) are important mediators of the innate immune response. Our aim was to evaluate TLR9 expression in peripheral B cells, taken from inflammatory bowel disease (IBD) patients before and after anti-inflammatory treatment. Nineteen patients with IBD (12-crohns disease, 7-ulcerative colitis) and 18 healthy controls were included in the study. Disease severity was assessed using the Pediatric/Adults crohns disease activity index and the ulcerative colitis activity index as needed. Accordingly, patients were classified as mild, moderate or severe disease. Peripheral B cells isolated from IBD patients, before and after anti-inflammatory treatment, and from the control group, were cultured for 24 h with and without CpG oligodeoxynucleotides (ODN-CpG) 0.5 μM. TLR9 expression by memory B cells (CD19+CD27+) was assessed by flow cytometry. RESULTS We found that TLR9 expression by peripheral B cells was significantly higher in IBD patients than that in healthy controls (12.42 ± 9.5 MFI vs. 6.0 ± 2.6 MFI p = 0.02). The addition of ODN-CpG to B cells resulted in a significantly increase of TLR9 expression in B cells from healthy controls (6.5 ± 3.2 MFI vs. 8.8 ± 4.2 MFI p = 0.007). On the contrary, B cells from IBD patients only partly respond to the addition of ODN-CpG after anti-inflammatory treatment (6.3 ± 3.8 vs. 7.3 ± 3.7, p = 0.1). TLR9 expression was positively correlated with IBD disease severity (r = 0.681, p < 0.0001). CONCLUSIONS TLR9 expression in memory B from IBD patients is elevated and associated with disease severity.

Giant cell hepatitis with autoimmune hemolytic anemia and hemophagocytosis.

Giant cell hepatitis (GCH) is a common histopathologic finding in infants with neonatal cholestasis and is regarded as a reaction of the neonatal liver to various insults. In contrast, GCH in association with autoimmune hemolytic anemia (AHA) is a rare disease of early childhood with unknown pathogenesis and poor prognosis. Although an initial response to immunosuppressive therapy has been reported, most patients progress to liver failure and die (1–8). Orthotopic liver transplantation in these patients results in disease recurrence in the transplanted liver within weeks after transplantation (4). An autoimmune etiology has been suggested for GCH with AHA because of the association with Coombspositive hemolytic anemia and the response to immunosuppressive therapy. However, in contrast to classic autoimmune hepatitis, liver biopsies show diffuse giant cell transformation and do not meet the histologic criteria accepted for the diagnosis of autoimmune hepatitis (1– 5,8). We report a patient with GCH with AHA with associated multiple autoimmune phenomena who responded briefly to steroids, azathioprine and FK 506 (Tacrolimus), but ultimately died 14 months after disease onset with hepatic failure and encephalopathy. Evidence of hemophagocytosis was present on postmortem examination within bone marrow, spleen, and lymph nodes.

The effect of early treatment in children with chronic hepatitis

Background The aim of this study was to compare the efficacy of interferon alpha (IFN) or IFN and ribavirin (IFN+RIB) combination therapy in children with chronic hepatitis C (CHC). Most children were infected during treatment for pediatric malignancies. Patients and Methods We reviewed the charts of 20 patients (11 boys and 9 girls) aged 10.6 ± 3.7 years with CHC who were treated between 1995 and 2001. Seven patients diagnosed with CHC before 1998 were treated with 3 million units of IFN three times weekly for 6 to 12 months. Thirteen children diagnosed after 1998 were treated with 3 million units of IFN three times weekly plus 15 mg/kg of ribavirin daily for 6 months (IFN+RIB). Results Demographic and clinical characteristics were not different between the two treatment groups. A sustained complete response defined as serum alanine aminotransferase normalization and hepatitis C virus RNA clearance at 6 and 12 months after termination of treatment occurred in three of seven children (43%) treated with IFN monotherapy compared with 7 of 12 children (54%) in the group treated with IFN+RIB combination therapy (not significant). The only difference between responders and nonresponders was the duration of infection before the initiation of therapy, which was significantly shorter in responders (1 ± 0.3 vs. 5.6 ± 2.2; P = 0.001). Conclusions In this small cohort of children with CHC, early initiation of antiviral treatment was associated with a sustained response rate independent of treatment type. Regular follow-up of children at risk of acquiring hepatitis C virus infection should assist in the early diagnosis. Early initiation of antiviral treatment may improve the rate of sustained response.

Upper airway obstruction as a presenting sign of achalasia in childhood.

Achalasia is an uncommon motility disorder of unknown aetiology. It is characterized by failure of the inferior sphincter of the oesophagus to relax in response to swallowing, made worse by the absence of peristaltic waves in the body of the oesophagus (1, 2). Its prevalence is 1/100 000 (3). The condition primarily affects adolescents and adults. Children under the age of 4 y constitute fewer than 5% of patients (4), and only 4– 5% of all patients with achalasia are symptomatic prior to the age of 15 (5). The gastro-oesophageal symptoms of achalasia in childhood are dysphagia and regurgitation of undigested food, which occurs in 80% of the patients, and failure to gain weight, which is present in 70% of the children (6, 7). Although achalasia in childhood is extremely rare, the severity of the pulmonary symptoms is more profound than in adults (6). We present a case in which cough and evidence of upper airway obstruction were the presenting manifestations of achalasia, and review the literature concentrating on pulmonary disease associated with achalasia.

Glutamine attenuates the inhibitory effect of methotrexate on TLR signaling during intestinal chemotherapy-induced mucositis in a rat

Toll-like receptor 4 (TLR-4) is crucial in maintaining intestinal epithelial homeostasis, participates in a vigorous signaling process and heightens inflammatory cytokine output. The objective of this study was to determine the effects of glutamine (GLN) on TLR-4 signaling in intestinal mucosa during methotrexate (MTX)-induced mucositis in a rat. Male Sprague–Dawley rats were randomly assigned to one of four experimental groups of 8 rats each: 1) control rats; 2) CONTR-GLN animals were treated with oral glutamine given in drinking water (2%) 48 hours before and 72 hours following vehicle injection; 3) MTX-rats were treated with a single IP injection of MTX (20 mg/kg); and 4) MTX-GLN rats were pre-treated with oral glutamine similar to group B, 48 hours before and 72 hours after MTX injection. Intestinal mucosal damage, mucosal structural changes, enterocyte proliferation and enterocyte apoptosis were determined 72 hours following MTX injection. The expression of TLR-4, MyD88 and TRAF6 in the intestinal mucosa was determined using real time PCR, Western blot and immunohistochemistry. MTX-GLN rats demonstrated a greater jejunal and ileal mucosal weight and mucosal DNA, greater villus height in ileum and crypt depth and index of proliferation in jejunum and ileum, compared to MTX animals. The expression of TLR-4 and MyD88 mRNA and protein in the mucosa was significantly lower in MTX rats versus controls animals. The administration of GLN increased significantly the expression of TLR-4 and MyD88 (vs the MTX group). In conclusion, treatment with glutamine was associated with up-regulation of TLR-4 and MyD88 expression and a concomitant decrease in intestinal mucosal injury caused by MTX-induced mucositis in a rat.