Patrizia D’Eufemia

Determination of urinary orotic acid and uracil by capillary zone electrophoresis.

We describe a simple method for measuring orotic acid and uracil concentration in urine by capillary zone electrophoresis in 20 mM Na-borate buffer, pH 9.2. The method was applied for studying a patient with HHH (hyperomithinemia, hyperammonemia and homocitrullinuria) syndrome. A high value of uracil excretion was found during periods of relatively low orotic acid excretion and normal ammonemia. The orotic acid level in urine was increased by increasing protein intake.

Effect of D-Ribose Administration to a Patient with Inherited Deficit of Adenylosuccinase

Adenylosuccinase (EC 4.3.2.2; ASase) deficiency is a newly discovered inborn error of metabolism that involves the purine de novo pathway and results in the accumulation of dephosphorylated substrate derivatives of the defective enzyme, namely succinylaminoimidazole carboxamide (SAICA) riboside and succinyladenosine (S-Ado).1–3 Although substantial progress has been made regarding our knowledge of the inherited disease, including its characterisation at gene level,4–5 much work remains to be done, particularly with respect to the mechanisms whereby the defect exerts its deleterious effects on brain function.

Tyrosinemia type I: long-term outcome in a patient treated with doses of NTBC lower than recommended

Sir, The paper by El-Karasky et al. “NTBC therapy for tyrosinemia type 1: how much is enough?” raises the question if doses of nitisinone (NTBC) lower than recommended could be effective in the treatment of tyrosinemia type 1 [1]. The authors report that the duration of follow-up, which does not exceed 27 months, represents a limitation of their study. We follow a 15-year-old male patient with tyrosinemia type 1 diagnosed at 6 months of age and promptly enrolled in an NTBC trial [2]. He started treatment with the recommended average dose of 1 mg/kg/day divided in two doses. After 2 months of treatment, plasma and urinary succinylacetone were undetectable. An improvement in hepatic function was noted within 18 months and serum alpha-fetoprotein progressively decreased and normalized after 24 months. Before starting NTBC therapy, the hepatic ultrasonography showed multiple cirrhotic nodules that disappeared after 48 months of treatment. Our patient thrived well but corneal opacities occurred, when tyrosine levels exceeded 700 μmol/l because of dietary noncompliance. After 114 months of treatment, based on clinical and biochemical follow-up, we progressively reduced the NTBC dose to the actual dose of 0.55 mg/kg/day. The NTBC serum concentration always remained above the recommended level of 30 μmol/l and urinary succinylacetone remained undetectable. Until now, the patient is in good condition with normal growth and absence of biochemical and ultrasound evidence of liver injury. Our case suggests that doses of NTBC, lower than recommended, could be effective in the long-term outcome.

Serum brain-type creatine kinase increases in children with osteogenesis imperfecta during neridronate treatment

Background:Creatine kinase (Ck) catalyzes the reversible transfer of high-energy phosphate groups between adenosine triphosphate and phosphocreatine. The brain isoform (Ckbb) is greatly induced in mature osteoclasts, playing an important role in bone-resorbing function during osteoclastogenesis. High Ckbb serum level has been found in patients with osteopetrosis and in patients with bisphosphonate (BP)-induced osteopetrosis. BPs are considered the treatment of choice for children with osteogenesis imperfecta (OI), acting as potent inhibitors of bone resorption by suppressing the activity of osteoclasts.Methods:We determined total serum Ck and isoform activity in 18 prepubertal children with type I OI, before and during treatment with the BP neridronate infusions.Results:Basal serum Ckbb levels were slightly elevated with respect to controls (mean ± SD = 3.0 ± 2.7 vs. 2.0 ± 2.2) and progressively increased after neridronate treatment (t0 vs. t4: mean ± SD = 3.0 ± 2.7 to 10.8 ± 8.1), with significant increment after first, second, and fourth infusions (P < 0.01). An inverse correlation was found between serum Ckbb and serum CTx at basal level.Conclusion:Our results support previous observations that increased serum Ckbb reflects failure of osteoclasts or, at least, suppression of osteoclasts. Upon considering that BPs are long acting, this information could be useful to prevent the risk of overtreatment after long-term BP exposure in pediatric patients with OI.

Intraoperative bleeding in patients with osteogenesis imperfecta type III treated by Fassier-Duval femoral rodding: analysis of risk factors

The surgical treatment of osteogenesis imperfecta (OI) is negatively influenced by clinical features such as osteoporosis, limb deformities and bone changes caused by bisphosphonate therapy. Blood loss during femoral nailing surgeries in patients with OI is a serious problem. Platelet anomalies have been associated with an elevation of the serum pyrophosphate originating from the platelets during clotting, even if the causality with the platelet dysfunction has not yet been established. To identify predictive risk factors regarding intraoperative bleeding, a retrospective analysis was conducted on 23 patients aged between 6 and 13 years, affected by OI type III, who were treated to correct femoral deformities or to perform an osteosynthesis for femoral shaft fractures, using the Fassier–Duval telescopic nail. Osteotomies were performed in 14 cases of deformities and in two out of seven cases of fractures. A survey about the bleeding had been obtained by calculating the sum of the blood aspirated and that lost with the gauzes or present on the surgical drapes. To obtain an estimate of the intraoperative blood losses, one must resort to a calculation based on an algorithm that evaluates the ratio between the effective blood loss divided by the total blood volume expected as per age and weight (&ggr; distribution). The average blood loss was 237.4 ml (0.12 &ggr;). In seven cases, it was necessary to perform postoperative transfusions, owing to an average blood loss of 502.8 ml (0.27 &ggr;). Patients aged less than 10 years had a minor blood loss. A greater number of osteotomies was associated with a significant increase of average bleeding (P=0.046). Patients who were never treated with bisphosphonates showed a significantly greater bleeding rate (P=0.048). Patients affected by OI type III have a high risk of severe blood loss during surgery, even caused by the platelet disfunction, which characterizes this OI type. In addition to this predisposing factor, there are other risk factors to consider in preoperative surgical planning. In patients who were never treated with bisphosphonates, the bleeding was higher than in the ones treated with bisphosphonates since at least 1 year. The effects of bisphosphonates on bone tissue (such as the medullar canal narrowing and the bone cortex thickening) could reduce the spongious bone amount and the bleeding. Inhibiting the farnesyl pyrophosphate synthase enzyme and reducing the prenylation of many plasma proteins, including the methylene tetrahydrofolate reductase, the bisphosphonates could lead to an alteration of the coagulation cascade. The correlation found with the intake of bisphosphonates, capable of inhibiting the action of the farnesyl pyrophosphate synthase enzyme, thus influencing coagulation, requires further prospective studies with research of the methylene tetrahydrofolate reductase mutation in patients with OI type III undergoing surgical procedures. The number of osteotomies, the patient’s age and the intake of bisphosphonates for at least 1 year seem to be the best predictive factors for blood loss.

Fatty acid profile of oesophageal mucosa in children with gastro-oesophageal reflux disease

BACKGROUND Polyunsaturated fatty acids, as precursors of eicosanoids, are involved in the pathogenesis of oesophageal mucosal damage and healing. AIMS To evaluate a possible role of polyunsaturated fatty acids in the pathogenesis of gastro-oesophageal reflux, we assayed fatty acids profile of oesophageal mucosal specimens obtained by endoscopy in children without oesophageal disease and children affected by gastro-oesophageal reflux disease. PATIENTS Eighteen children with normal 24-h oesophageal pH monitoring (GOR- group) and 18 children with gastro-oesophageal reflux disease (GOR+ group, eight with oesophagitis and 10 without), were included in the study. METHODS Fatty acids were extracted from oesophageal mucosal specimens obtained by endoscopy and assayed by gas chromatography. RESULTS In the GOR+ group we observed an increased percentage of mucosal polyunsaturated fatty acids, mainly arachidonic and docosohexaenoic acids (p<0.01), without differences between groups with and without oesophagitis. Significant positive correlation was found between reflux index and docosahexaenoic acid (r=0.805; p<0.001). CONCLUSIONS The results obtained show that the current methods are able to reveal changes between normal and pathological mucosa that could be relevant in the pathogenesis of gastro-oesophageal reflux disease.

Clinical and biochemical response to neridronate treatment in a patient with osteoporosis-pseudoglioma syndrome (OPPG)

Osteoporosis-pseudoglioma syndrome (OPPG) is a rare autosomal recessive syndrome characterized by juvenile-onset osteoporosis and ocular abnormalities due to a low-density lipoprotein receptor-related protein 5 (LRP5) gene mutation. Treatment with bisphosphonates, particularly with pamidronate and risedronate, has been reported to be of some efficacy in this condition. We report on a patient with OPPG due to an LRP5 gene mutation, who showed an encouraging response after a 36-month period of neridronate therapy. We report a case of a patient treated with bisphosphonates. Bisphosphonates should be administered in OPPG patients as a first-line therapy during early childhood.

Isolated olecranon fractures in children affected by osteogenesis imperfecta type I treated with single screw or tension band wiring system: Outcomes and pitfalls in relation to bone mineral density

Abstract The purpose of this study is to compare the results of 2 techniques, tension band wiring (TBW) and fixation with screws, in olecranon fractures in children affected with osteogenesis imperfecta (OI) type I. Between 2010 and 2014, 21 olecranon fractures in 18 children with OI (average age: 12 years old) were treated surgically. Ten patients were treated with the screw fixation and 11 with TBW. A total of 65% of olecranon fractures occurred as a result of a spontaneous avulsion of the olecranon during the contraction of the triceps muscle. The average follow-up was 36 months. Among the children treated with 1 screw, 5 patients needed a surgical revision with TBW due to a mobilization of the screw. In this group, the satisfactory results were 50%. In patients treated with TBW, the satisfactory results were 100% of the cases. The average Z-score, the last one recorded in the patients before the trauma, was −2.53 in patients treated with screw fixation and −2.04 in those treated with TBW. TBW represents the safest surgical treatment for patients suffering from OI type I, as it helps to prevent the rigidity of the elbow through an earlier recovery of the range of motion, and there was no loosening of the implant. In analyzing the average Z-score before any fracture, the fixation with screws has an increased risk of failure in combination with low bone mineral density.

Osteogenesis imperfecta and clubfoot—a rare combination: Case report and review of the literature

Background: Osteogenesis imperfecta (OI) is a rare congenital genetic osteodystrophy, which has a prevalence of 1:20,000. OI is caused by the mutation of the COL1A1/COL1A2 genes, leading to a deficit of quality and/or quantity in the synthesis of procollagen-&agr; type 1. Seven different forms of diverse clinical entity have been classified by Sillence and Glorieux, although, recently, up to 11 forms characterized by different genetic mutations have been recognized. Patients with OI suffer from extreme bone fragility and osteoporosis, which often predisposes them to frequent fractures. This paper presents the case of a child with OI type IV who, at birth, was also diagnosed with a severe clubfoot (congenital talipes equinovarus) grade III. Patients mother also suffers from OI type IV. Methods: The treatment was started by placing femoro-podalic corrective casts, according to the Ponseti method, but some unexpected problems occurred during this treatment. When the patient was 3 months of age, we decided to correct the clubfoot before the time limit planned, performing a bilateral posteromedial surgical release. Results: Three weeks after surgery the casts were removed and replaced with bilateral Spica cast-like braces. On the 6th postoperative week, the patient began wearing Bebax corrective shoes, after 1 year ambidextrous orthopedic shoes. Now, he is 2 years old and has started to walk properly without any orthesis. Conclusion: In the presence of an orthopedic pathology associated with OI, it is recommended to manage the patient according to the underlying pathology, always considering the bone fragility associated with OI. The final surgical treatment to correct the clubfoot can be done earlier, if necessary. In our opinion, this uncommon association between OI and clubfoot is non-syndromic. This means that the two congenital diseases are not necessarily included in a singular uncommon genetic syndrome, but the clubfoot was caused by multifactorial causes, especially by both the mothers bisphosphonate drug therapy and the amniocentesis performed during her pregnancy to drain polyhydramnios. In our analysis, those environmental factors could have interacted with an already altered genetic substratum, contributing to develop this rare combination of congenital disorders.