Food or medicine? A European regulatory perspective on nutritional therapy products to treat inborn errors of metabolism

Dietary or nutritional management strategies are the cornerstone of treatment for many inborn errors of metabolism (IEMs). Though a vital part of standard of care, the products prescribed for this are often not formally registered as medication. Instead, they are regulated as food or as food supplements, impacting the level of oversight as well as reimbursed policies. This scoping literature review explores the European regulatory framework relevant to these products and its implications for current clinical practice. Searches of electronic databases (PubMed, InfoCuria) were carried out, supplemented by articles identified by experts, from reference lists, relevant guidelines and case-law by the European Court of Justice. In the European Union (EU), nutritional therapy products are regulated as food supplements, food for special medical purposes (FSMPs) or medication. The requirements and level of oversight increase for each of these categories. Relying on lesser-regulated food products to treat IEMs raises concerns regarding product quality, safety, reimbursement and patient access. In order to ascertain whether a nutritional therapy product functions as medication and thus could be classified as such, we developed a flowchart to assess treatment characteristics (benefit, pharmacological attributes, and safety) with a case-based approach. Evaluating nutritional therapy products might reveal a justifiable need for a pharmaceutical product. A flowchart can facilitate systematically distinguishing products that function medication-like in the management of IEMs. Subsequently, finding and implementing appropriate solutions for these products might help improve the quality, safety and accessibility including reimbursement of treatment for IEMs.

The natural history of classic galactosemia: lessons from the GalNet registry

BACKGROUND

Classic galactosemia is a rare inborn error of carbohydrate metabolism, caused by a severe deficiency of the enzyme galactose-1-phosphate uridylyltransferase (GALT). A galactose-restricted diet has proven to be very effective to treat the neonatal life-threatening manifestations and has been the cornerstone of treatment for this severe disease. However, burdensome complications occur despite a lifelong diet. For rare diseases, a patient disease specific registry is fundamental to monitor the lifespan pathology and to evaluate the safety and efficacy of potential therapies. In 2014, the international Galactosemias Network (GalNet) developed a web-based patient registry for this disease, the GalNet Registry. The aim was to delineate the natural history of classic galactosemia based on a large dataset of patients.

METHODS

Observational data derived from 15 countries and 32 centers including 509 patients were acquired between December 2014 and July 2018.

RESULTS

Most affected patients experienced neonatal manifestations (79.8%) and despite following a diet developed brain impairments (85.0%), primary ovarian insufficiency (79.7%) and a diminished bone mineral density (26.5%). Newborn screening, age at onset of dietary treatment, strictness of the galactose-restricted diet, p.Gln188Arg mutation and GALT enzyme activity influenced the clinical picture. Detection by newborn screening and commencement of diet in the first week of life were associated with a more favorable outcome. A homozygous p.Gln188Arg mutation, GALT enzyme activity of ≤ 1% and strict galactose restriction were associated with a less favorable outcome.

CONCLUSION

This study describes the natural history of classic galactosemia based on the hitherto largest data set.

First report of carglumic acid in a patient with citrullinemia type 1 (argininosuccinate synthetase deficiency)

WHAT IS KNOWN AND OBJECTIVE

Carglumic acid is a structural analogue of human N-acetylglutamate, which has become an alternative therapeutic option for hyperammonaemia in organic acidaemias such as isovaleric acidaemia, methylmalonic acidaemia and propionic acidaemia, and it has been suggested in other urea cycle disorders such as ornithine transcarbamylase deficiency and carbamoyl phosphate synthetase 1 deficiency.

CASE DESCRIPTION

A male newborn was diagnosed with citrullinemia after serum amino acid analyses revealed markedly elevated citrulline concentration together with homozygous p.Gly390Arg mutation in ASS1 gene. The ammonia concentration decreased and blood gas analysis normalized after peritoneal dialysis was performed for three days. Also, sodium benzoate, L-arginine and parenteral nutrition with glucose and lipid therapy were initiated. Until 1 year of age, low adherence to sodium benzoate therapy due to unpleasant taste caused hyperammonaemic episodes and obligated us to initiate carglumic acid (100 mg/kg/day) therapy. During treatment with carglumic acid, the median ammonia level was 45.6 µmol/L. The patient's treatment was switched from carglumic acid to sodium phenylbutyrate when he was 4.5 years old. Currently, the patient is 6.5 years old and remains under follow-up with sodium phenylbutyrate, L-arginine and protein-restricted diet. Plasma ornithine level was found to be significantly lower during the carglumic acid treatment compared to other treatments (P=.039). Also, glutamic acid was found to be higher during the sodium benzoate treatment period compared to other treatment periods (P=.024).

WHAT IS NEW AND CONCLUSION

To the best of our knowledge, this is the first report describing the long-term use of carglumic acid in a patient with argininosuccinate synthetase deficiency.

Cysteamine revisited: repair of arginine to cysteine mutations

Cysteamine is a small aminothiol endogenously derived from coenzyme A degradation. For some decades, synthetic cysteamine has been employed for the treatment of cystinosis, and new uses of the drug continue to emerge. In this review, we discuss the role of cysteamine in cellular and extracellular homeostasis and focus on the potential use of aminothiols to reconstitute the function of proteins harboring arginine (Arg) to cysteine (Cys) mutations, via repair of the Cys residue into a moiety that introduces an amino group, as seen in basic amino acid residues Lys and Arg. Cysteamine has been utilized in vitro and ex vivo in four different genetic disorders, and thus provides "proof of principle" that aminothiols can modify Cys residues. Other aminothiols such as mercaptoethylguanidine (MEG) with closer structural resemblance to the guanidinium moiety of Arg are under examination for their predicted enhanced capacity to reconstitute loss of function. Although the use of aminothiols holds clinical potential, more studies are required to refine specificity and treatment design. The efficacy of aminothiols to target proteins may vary substantially depending on their specific extracellular and intracellular locations. Redox potential, pH, and specific aminothiol abundance in each physiological compartment are expected to influence the reactivity and turnover of cysteamine and analogous drugs. Upcoming research will require the use of suitable cell and animal models featuring Arg to Cys mutations. Since, in general, Arg to Cys changes comprise about 8% of missense mutations, repair of this specific mutation may provide promising avenues for many genetic diseases.

Citrullinemia type 1: genetic diagnosis and prenatal diagnosis in subsequent pregnancy

Citrullinemia type 1 was diagnosed by tandem mass spectrometry in a full term male neonate who presented with an acute catastrophic collapse on the 3rd day of life. Both parents were identified to be carriers for the exon 15 p Gly390Arg mutation in the argininosuccinate synthetase gene located at chromosome 9q34.1. Chorionic villus sampling and prenatal genetic testing in the subsequent pregnancy revealed an affected fetus resulting in termination of pregnancy.

Long-term outcome of patients with argininosuccinate lyase deficiency diagnosed by newborn screening in Austria

Twenty-three patients with late onset argininosuccinate lyase deficiency (ASLD) were identified during a 27-year period of newborn screening in Austria (1:95,600, 95% CI=1:68,036-1:162,531). One additional patient was identified outside the newborn screening with neonatal hyperammonemia. Long-term outcome data were available in 17 patients (median age 13 years) ascertained by newborn screening. Patients were treated with protein restricted diet and oral arginine supplementation during infancy and childhood. IQ was average/above average in 11 (65%), low average in 5 (29%), and in the mild intellectual disability range in 1 (6%) patients. Four patients had an abnormal EEG without evidence of clinical seizures and three had abnormal liver function tests and/or evidence of hepatic steatosis. Plasma citrulline levels were elevated in four patients. Plasma ammonia levels were within normal range prior and after a protein load in all patients. Seven different mutations were identified in the 16 alleles investigated. Four mutations were novel (p.E189G, p.R168C, p.R126P, and p.D423H). All mutations were associated with low argininosuccinate lyase activities (0-15%) in red blood cells. Newborn screening might be beneficial in the prevention of chronic neurologic and intellectual sequelae in late onset ASLD, but a proportion of benign variants might have contributed to the overall favorable outcome as well.

Highly variable clinical phenotype of carbamylphosphate synthetase 1 deficiency in one family: an effect of allelic variation in gene expression?

Deficiency of the urea cycle enzyme carbamylphosphate synthetase 1 (CPS1) causes hyperammonemia with a vast range of clinical severity from neonatal onset with early lethality to onset after age 40 with rare episodes of hyperammonemic confusion. The cause for this variability is not understood. We report two patients from one family with highly divergent clinical course, one presenting neonatally with a fatal form and the other at age 45 with benign diet-responsive disease. The patients are compound heterozygous for two mutations of the CPS1 gene, c.3558 + 1G > C and c.4101 + 2T > C. The haplotypes containing each mutation are identical between the two patients, as are the sequences of CPS1 exons and flanking introns. Transcriptional experiments show that the abnormal CPS1 transcripts generated by both mutations are identical in these two patients. We characterize promoter and enhancer sequences of the CPS1 gene and find also in these regions no sequence differences between patients. Finally, we perform cloning experiments and find that in the neonatal-onset case, clones of messenger RNA (mRNA) expressed from the allele carrying the c.4101 + 2T > C mutation are threefold more than clones of mRNA from the allele with the c.3558 + 1G > C mutation, whereas in the adult-onset case the two types of clones are equal, indicating skewed expression towards the c.4101 + 2T > C allele in the neonatal case. Although we are yet to understand the mechanism of this differential expression, our work suggests that allelic imbalance may explain clinical variability in CPS1 deficiency in some families.

Proven germline mosaicism in a father of two children with CHARGE syndrome

CHARGE syndrome is an autosomal dominant malformation syndrome caused by mutations in the CHD7 gene. The majority of cases are sporadic and only few familial cases have been reported. In these families, mosaicism in one parent, as well as parent- to-child transmission of a CHD7 mutation, has been described. In some further cases, germline mosaicism has been suggested. Here, we report the first case in which germline mosaicism could be demonstrated in a father of two affected children with CHARGE syndrome. The truncating mutation c.7302dupA in exon 34 of the CHD7 gene was found in both affected children but was not detected in parental lymphocytes. However, in DNA extracted from the father's spermatozoa, the c.7302dupA mutation could be identified. Furthermore, mutation analysis of DNA isolated from 59 single spermatozoa revealed that the c.7302dupA mutation occurs in 16 spermatozoa, confirming germline mosaicism in the father of the affected children. This result has a high impact for genetic counselling of the family and for their recurrence risk in further pregnancies.

Amino acids in CSF and plasma in hyperammonaemic coma due to arginase1 deficiency

We report the CSF and plasma amino acid concentrations and their ratios in a male patient with arginase1 deficiency with an unusual early presentation at 34 days of age. He developed hyperammonaemic coma (ammonia >400 μmol/L; normal <90 μmol/L) on postnatal day 35. CSF and plasma concentrations were assayed by ion-exchange chromatography on day 36. Arginine was increased both in plasma (971 μmol/L; controls (mean ± 2SD) 50 ± 42) and in CSF (157 μmol/L; controls 19 ± 8.6), resulting in a normal CSF/plasma ratio of 0.16 (controls 0.41 ± 0.26). Interestingly, glutamine was disproportionately high in CSF (3114 μmol/L; controls 470 ± 236) but normal in plasma (420 μmol/L; controls 627 ± 246); the ratio exceeded unity (7.4; controls 0.76 ± 0.31). The CSF/plasma ratios of most neutral amino acids were elevated but not those of the imino- and of the dibasic amino acids lysine and ornithine. The mechanism leading to the increase of most neutral amino acids in brain is not known.

CONCLUSION

A normal glutamine in plasma does not exclude an increased concentration in CSF; it could be useful to ascertain by MRS that a high CSF glutamine concentration truly reflects a high concentration in brain tissue for better understanding its pathogenesis.

Pseudodeficiency of glutamine in infant liver disease

Gamma-glutamyltransferase (gamma-GT) is an early marker for cholestasis and has the capability of glutamine-deamidation. Two infants with elevated serum gamma-GT had a decreased serum glutamine. A time course of glutamine and glutamate concentration changes was performed. This revealed a time dependent decrease of glutamine far below the normal lower limit while glutamate increased above the normal upper limit. In conclusion, increased in vitro gamma-GT can cause pseudodeficiency of glutamine. To avoid pitfalls, physicians should inform the laboratory on accompanying pathologies.

Glutamine synthetase is essential for proliferation of fetal skin fibroblasts

Background. Glutamine synthetase (GS) is ubiquitously expressed in the human and plays a major role for many metabolic pathways. However, little is known about its role during the fetal period. Methods. Cultured skin fibroblasts derived from an aborted fetus deficient in GS activity due to a R324C exchange as well as fetal and mature controls were used to determine the level of GS-expression, apoptosis, and proliferation in presence or absence of exogenous glutamine. Results. Glutamine synthetase can be found at early gestational stages. Loss of GS activity either inherited or induced through l-methionine sulfoximine leads to an upregulation of the GS protein but not of the GS mRNA and results in a significant drop in the proliferation rate but has no effect on apoptosis. Exogenous glutamine does not influence the rate of apoptosis but increases proliferation rates of the fetal but not the mature fibroblasts. Conclusion. GS can be found during early human fetal stages when it displays a significant effect on cell proliferation.

Intermediate hyperhomocysteinaemia and compound heterozygosity for the common variant c.677C>T and a MTHFR gene mutation

Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in the regulation of plasma homocysteine levels. MTHFR deficiency, an autosomal recessive disorder, results in homocystinuria and hypomethioninaemia and presents with highly variable symptoms affecting many organs but predominantly the central nervous system. The common polymorphism of the MTHFR gene, c.677C>T, a known risk factor for elevated plasma homocysteine levels, occurs frequently in the caucasian population. In this study we investigated three subjects with moderate hyperhomocysteinaemia (total plasma homocysteine 72 micromol/L in case 1 and 90 micromol/L in case 3, total non-protein-bound homocysteine 144-186 micromol/L in case 2) but different clinical presentation with no symptoms in case 1, muscle weakness at 17 years of age in case 2, and syncopes and cerebral convulsions at 18 years of age in case 3. Each subject was compound heterozygous for the c.677C>T polymorphism and a novel mutation of the MTHFR gene (case 1: c.883G>A [p.D291N]; case 2: c.1552_c.1553delGA [p.E514fsX536]; case 3: c.616C>T [p.P202S]). Moderately decreased fibroblast MTHFR activity was associated with severely reduced affinity for NADPH and increased sensitivity to inhibition by S-adenosylmethionine (AdoMet) in case 2, and with mild FAD responsiveness in case 3. In case 1, fibroblast MTHFR activity was normal but the sensitivity to inhibition by AdoMet was slightly reduced. This study indicates that the sequence alteration c.677C>T combined with severe MTHFR mutations in compound heterozygous state may lead to moderate biochemical and clinical abnormalities exceeding those attributed to the c.677TT genotype and might require in addition to folate substitution further therapy to normalize homocysteine levels.

Misleading diagnosis of partial N-acetylglutamate synthase deficiency based on enzyme measurement corrected by mutation analysis

N-acetylglutamate synthase (NAGS) deficiency is a rare urea cycle disorder. Most of the patients present in the early neonatal period with severe hyperammonaemia and marked neurological impairment. We report on a Turkish family with an index patient, who died due to hyperammonemia, and another three siblings, who received a prophylactic treatment consisting of arginine hydrochloride, sodium benzoate and phenylbutyrate directly after birth. Enzyme measurement in a liver biopsy suggested a diagnosis of partial NAGS deficiency in all three siblings. Thereafter, N-carbamylglutamate was added to the treatment. None of the patients developed hyperammonaemia. After the human NAGS gene was identified, mutation analysis revealed that the consanguineous parents and two siblings were heterozygous for a private mutation (W484R), whereas the wild-type gene was found in the eldest sibling. Therapy was stopped without any deterioration of urea cycle function.

CONCLUSION

Diagnosis of partial NAGS deficiency based on enzyme measurement may be misleading and should be completed by mutation analysis.

Gene structure of human carbamylphosphate synthetase 1 and novel mutations in patients with neonatal onset

Carbamylphosphate synthetase 1 (E.C. 6.3.4.16) deficiency is a rare autosomal recessive disorder of the urea cycle that can result in severe neonatal hyperammonemia. Since the genomic structure of the CPS1 gene was not yet elucidated, mutation detection was performed by analysis of transcripts in the past. Here, we present the entire DNA sequence of the human CPS1 gene including all exon-intron boundaries. Moreover, mutation analysis was performed in six patients leading to the detection of 9 novel mutations including the missense mutations c.2528T>C and c.2623A>G, the nonsense mutations c.712C>T and c.2115ins35bp, the splice site mutations c.1263+5G>C, c.3558+1G>C and c.4101+2T>C, and a small deletion c.3036_3038delGGT. The mutations c.2528T>C and c.2623A>G were identified on a double mutated allele. New data on the genomic structure of the CPS1 gene provided in this study are useful to characterize the heterogenous molecular basis of the disease in patients deficient for carbamylphosphate 1 deficiency.

Diagnosis of N-acetylglutamate synthase deficiency by use of cultured fibroblasts and avoidance of nonsense-mediated mRNA decay

Molecular diagnosis of N-acetylglutamate synthase deficiency (NAGSD) has become possible now that the corresponding gene has been identified. We describe the genetic analysis of a patient with NAGSD using low-level transcripts derived from cultured fibroblasts. One defective allele (c.1306-1307insT) was detected by PCR amplification. However, the transcript from a second mutation (IVS3 - 2A>T), causing aberrant splicing with the generation of a premature termination codon, was not detected until interference of nonsense-mediated mRNA decay was abrogated by the translation inhibitor cycloheximide. We demonstrate that low-level transcripts in cells that do not express significant enzyme activity are a valuable tool for molecular studies of genetic alterations, and suggest routine abrogation of nonsense-mediated mRNA decay using cycloheximide when transcript analysis is performed.

Structure of the human argininosuccinate synthetase gene and an improved system for molecular diagnostics in patients with classical and mild citrullinemia

Deficiency of argininosuccinate synthetase (ASS) causes citrullinemia, an autosomal recessive inherited defect of the urea cycle. Most patients described so far have presented with the classical form of the disease. There are also patients with a mild form of citrullinemia in whom the exact molecular basis and clinical relevance are uncertain. Mutations in the human ASS gene have not yet been described in mildly affected or asymptomatic patients with citrullinemia. The genomic sequence of the human ASS gene is not precisely known making mutation analysis difficult. Here, the entire genomic DNA sequence and mutations in the ASS gene of patients with the classical and mild form of the disease are described. The mutations c.1168G-->A (G390R) and IVS13+5 G-->A and the novel mutation c.323G-->T (R108L) have been found to be associated with classical citrullinemia, whereas the novel mutations c.535T-->G (W179R), and c.1085G-->T (G362V) have been detected on alleles of the mildly affected patients. Thus, mutations found in the human ASS gene of asymptomatic children with biochemical abnormalities and in some cases enzymatically proven citrullinemia have allowed us to classify these cases as ASS-deficient patients. The elucidation of the structure of the human ASS gene has made possible the use of intronic primers for molecular analysis of patients with mild disease and the classical form, and provides another option for prenatal diagnostics in affected families with the severe type.

Cervical encephalocele in a newborn--Chiari III malformation. Case report and review of the literature

Chiari malformations are brain stem anomalies with or without spinal canal involvement. The combination of brain stem and cerebellar anomaly with a cervical cele is named Chiari III malformation. Patients with this extremely rare defect frequently present with severe neurological defects and can have a poor prognosis. Following a report on a newborn child with a Chiari III malformation that took a fatal but typical course the literature is reviewed.

Genetic analysis of carbamoylphosphate synthetase I and ornithine transcarbamylase deficiency using fibroblasts

Deficiencies of carbamoylphosphate synthetase or of ornithine transcarbamylase, two urea cycle enzymes located within mitochondria, often present as severe neonatal hyperammonaemic crises and have a poor prognosis. While genetic analysis of the X-chromosomal transmitted ornithine transcarbamylase deficiency (OTC) is performed by exon-wise mutation screening of genomic DNA in most cases, identification of mutations in the autosomal inherited carbamoylphosphate synthetase (CPS 1) deficiency requires analysis of transcripts due to the unknown genomic structure. We tested the hypothesis that CPS 1 and OTC are expressed at low levels in fibroblasts and indeed were able to amplify full-length cDNA from that source. Using a reverse transcriptase polymerase chain reaction based procedure we completely characterised the genetic background in five patients and identified three novel mutations and a novel polymorphism of the CPS 1 gene (deletion/insertion 2170delGCTCinsCCA, nonsense mutation 2359C > T, missense mutation 3161T > G and Thr1406Asn, respectively), as well as the missense mutations 482A > G and 994T > A of the OTC gene.

CONCLUSION

Cultured fibroblasts are an easily accessible source for genetic analysis of inborn errors of urea cycle enzymes which are functionally expressed only in liver and gut.

New strategies in diagnosis and treatment of thrombotic thrombocytopenic purpura: case report and review

The pentad of thrombocytopenia, haemolytic anaemia, mild renal dysfunction, neurological signs and fever, classically characterizes the syndrome of thrombotic thrombocytopenic purpura (TTP). TTP usually occurs in adults but also children have been described with this condition. The disorder may take a relapsing course, termed chronic relapsing TTP (CRTTP), which although very rare, may also begin in childhood. Deficiency of a recently identified enzyme, the von Willebrand factor (vWF)-cleaving protease, seems to play a major role in the development of TTP. We report on a 3-year-old boy with a dramatic but typical clinical course of CRTTP. At the time of diagnosis, neurological deficits and multiple cerebral infarctions had already occurred. In plasma, vWF-cleaving protease was completely absent, both during acute TTP and in remission. There was no protease inhibitor detected. Regular infusions of fresh frozen plasma were successfully given for replacement on a prophylactic basis.

CONCLUSION

Assay of von Willebrand factor-cleaving protease helps to diagnose a form of thrombotic thrombocytopenic purpura which may be managed by prophylactic treatment with fresh frozen plasma.

Studying patients with inflammatory back pain and arthritis of the lower limbs clinically and by magnetic resonance imaging: many, but not all patients with sacroiliitis have spondyloarthropathy

OBJECTIVE

Clinical and magnetic resonance imaging (MRI) data of 170 consecutive patients with inflammatory back pain (IBP) and/or oligoarthritis of the lower limbs were evaluated in a retrospective study. The aim was to determine the frequency of sacroiliitis and spondyloarthropathy (SpA) in this population, and to assess the significance of HLA B27 measurements for diagnosis in early disease.

METHODS

Pelvic X-rays were performed in all IBP patients and dynamic MRI of the sacroiliac joints in patients with IBP who had indefinite results on sacroiliac X-rays (n = 32).

RESULTS

European Spondyloarthropathy Study Group criteria for SpA were fulfilled by 106/170 patients (62.4%); eight additional patients had symptoms suggestive of SpA (4.7%). The most frequent SpA subset was undifferentiated SpA (uSpA), diagnosed in 46/106 patients (43.4%). Sacroiliitis was detected by MRI in 21/32 patients with IBP and unclear X-rays (65.6%). Of those, 14 were diagnosed as SpA and seven females with moderate unilateral sacroiliitis, but no features of SpA, also not on follow-up (at least 1 yr), were classified as undifferentiated sacroiliitis (US). Ten of the 14 SpA (71.4%) and none of the seven US patients were HLA B27 positive.

CONCLUSION

HLA B27 positivity in IBP patients with MRI-proven sacroiliitis positively predicts SpA. uSpA is a frequent SpA subset. There are HLA B27-negative non-SpA patients with moderate unilateral sacroiliitis whom we propose to be classified as US.

[Thrombocytic alpha-delta-storage-pool-disease: shortening of bleeding time after infusion of 1-desamino-8-D-arginine vasopressin]

BACKGROUND

The synthetic vasopressin derivate desmopressin (1-desamino-8-D-arginine vasopressin) has been reported to shorten the bleeding time in patients with hemophilia A, von Willebrand's disease and several functional platelet disorders. In addition to substitution of platelets, vasopressin is therefore used to prevent bleeding complications.

CASE

We report the case of a 14-year-old female patient with prolonged bleeding time due to the rare thrombocytic alpha-delta-storage-pool-disease. When normal donor platelet substitution alone was ineffective, bleeding time was normalised after infusion of desmopressin and elective wisdom-tooth extraction was performed without significant postoperative bleeding.

DISCUSSION

Infusion of desmopressin appears to be effective in shortening bleeding time in thrombocytic storage-pool-disease. Its use could prevent bleeding complications after trauma and surgical interventions and may possibly help to spare the need for platelet concentrates.

Nested polymerase chain reaction strategy simultaneously targeting DNA sequences of multiple bacterial species in inflammatory joint diseases. II. Examination of sacroiliac and knee joint biopsies of patients with spondyloarthropathies and other arthritides

OBJECTIVE

Bacteria play a crucial pathogenetic role in reactive arthritis (ReA) and other forms of spondyloarthropathy (SpA) and in Lyme arthritis. Although there is evidence of local persistence of bacterial antigens no definitive method revealing microbes in peripheral joints has been established. We detected DNA of individual bacteria in synovial material by PCR. Applying molecular technology we screened simultaneously for 8 bacterial genomes in arthritis and sacroiliitis.

METHODS

Sacroiliac (SI) biopsy specimens taken from the SI joint of 8 patients with ankylosing spondylitis (AS, n = 5) and undifferentiated SpA (uSpA, n = 3) by computed tomography guided biopsy were investigated for presence of bacterial DNA. Similarly, synovial membrane samples obtained by office arthroscopy from 15 patients with ReA (n = 5), uSpA (n = 3), undifferentiated oligoarthritis (uOligo, n = 3), and rheumatoid arthritis (RA, n = 4) were screened. Nested PCR was performed for DNA of the following bacteria: Chlamydia trachomatis, C. pneumoniae, Yersinia enterocolitica, Salmonella enteritidis, Campylobacter jejuni, Shigella flexneri, Klebsiella pneumoniae, and Borrelia burgdorferi.

RESULTS

No bacterial DNA was found in the SI biopsies of patients with uSpA and AS. DNA of B. burgdorferi (n = 2) and C. trachomatis (n = 1) was detected in 3 patients with uOligo, but not in patients with ReA or RA. DNA of other microbes including K. pneumoniae was not found. Patients' mean disease duration was 5.3 years (2 mo-8.4 yrs).

CONCLUSION

We found bacterial DNA in peripheral joints of patients with uOligo, while in patients with ReA, AS, and uSpA no bacterial DNA was detected in peripheral or SI joints. The failure to detect bacterial DNA in patients with SpA suggests autoimmune mechanisms operate in later stages of disease.

CT-guided intraarticular corticosteroid injection into the sacroiliac joints in patients with spondyloarthropathy: indication and follow-up with contrast-enhanced MRI

PURPOSE

Our goal was to prospectively study the therapeutic efficacy of CT-guided intraarticular corticosteroid instillation of inflamed sacroiliac joints (SIJs) in patients with spondyloarthropathies and to evaluate the role of MRI as a procedure for establishing the indication and for therapeutic follow-up.

METHOD

A total of 103 CT-guided corticosteroid injections of the SIJs were performed in 66 patients with inflammatory back pain (IBP): 37 bilateral, 29 unilateral. All patients did not respond to an immediately preceding 4 week nonsteroidal antiinflammatory therapy. Forty milligrams of a crystalline long-acting corticoid was instilled in each joint. All 66 patients underwent continuous clinical follow-up at 10 to 12 week intervals after corticosteroid injection to a maximum of 18 months. The degree of subjective complaints before and after the intervention was recorded using a analogue scale (0 = no pain, 10 = unbearable pain). Dynamic contrast-enhanced (Gd-DTPA, 0.1 mmol/kg body wt) MRI with quantitative determination of contrast enhancement was performed in all patients before the therapeutic intervention and in 38 patients at 8 +/- 4 months.

RESULTS

Sixty-one of the 66 study patients (92.5%) showed a statistically significant abatement of subjective complaints from 8.8 +/- 1.3 to 3.3 +/- 2.3 (p < 0.01) at 1.7 +/- 1.1 weeks after intervention, and this improvement lasted for 10 +/- 5 months. The percentage contrast enhancement at dynamic MRI likewise showed a significant reduction from 100.3 +/- 48% before to 44.3 +/- 36.1% after intraarticular cortisone administration (p < 0.01).

CONCLUSION

CT-guided intraarticular corticosteroid instillation in the SIJs may be regarded as an effective therapy for florid sacroiliitis. The severity of inflammation and the response to therapy can be determined quantitatively by dynamic MRI.

[Malignant fibrous histiocytoma: productive use of imaging procedures]

Malignant fibrous histiocytoma (MFH) of soft tissue is a rare tumor. We present a case of MFH in the bicipital muscle. Local muscle hypertrophy or lesions of the long tendon of the bicipital muscle may be a difficult differential diagnosis. This case is used for outlining advantages of ultrasound, computed tomography and magnetic resonance imaging. In conventional radiography MFH is seen as a soft-tissue tumor sometimes involving the bone. CT is the best way to test bone involvement. Tumor extension will be assessed with great accuracy by means of ultrasonics and magnetic resonance imaging (MRI).

[Stent-supported percutaneous therapy of iliac vein stenosis following operative thrombectomy and placement of a shunt]

Among 15 patients with acute thrombotic disease of pelvic veins who had been submitted to operative thrombectomy and creation of arteriovenous fistula in the groin, 12 presented with stenotic lesions 3 months later. These stenoses were submitted to percutaneous angioplasty. If angioplasty failed, percutaneous placement of a vascular stent (wall stent) was performed immediately (n = 7). Stenting in cross-over-technique proved practicable in all cases. Secondary stenotic disease in the exclusively dilated area was observed in 3/5 cases and was also treated with a wall stent. In one patient with recurrent stenoses who refused stenting, extended thrombosis occurred after occlusion of the AV-fistula. At mid-term PTA was successful in only two cases. Intimal hyperplasia was observed in only one wall stent treated patient. Percutaneous treatment of iliacal stenoses in patients with postthrombotic syndrome may be performed safely under the protective effect of the fistula. With the presented technique, patency of pelvic veins could be restored in 11/12 patients with postoperative significant venous stenoses.