The role of laboratory diagnostics in diagnostic workup of children with suspected rare neurometabolic diseases

Neurometaboličke bolesti u dječjoj dobi skupina su rijetkih bolesti koja se sve više širi. Tome uvelike pridonosi dostupnost novih tehnologija koje se primjenjuju u selektivnoj laboratorijskoj dijagnostici i novorođenačkom probiru nasljednih metaboličkih poremećaja. Zajedno s drugom dijagnostičkom obradom, takva dostupnost ujedno omogućuje kliničarima izbor dijagnostičkog pristupa. Brzi razvoj novih terapijskih mogućnosti za sve veći broj neurometaboličkih poremećaja ujedno nameće potrebu za što ranijim postavljanjem dijagnoze i odgovarajućim praćenjem tijeka liječenja. Na ove izazove moguće je odgovoriti višedisciplinskim pristupom bolesnom djetetu, a bitan je čimbenik i potpora čitavog društva.Neurometabolic diseases in children are an ever-increasing group of rare diseases. One of the major reasons for this is the availability of new technologies used in selective laboratory diagnostics and newborn screening for inherited metabolic disorders. Such availability also furnishes clinicians with the opportunity to select diagnostic approach. Rapid development of new therapeutic possibilities for an ever-rising number of neurometabolic disorders at the same time imposes the need for early diagnosis and appropriate monitoring of the course of therapy. It is possible to respond to these challenges by multidisciplinary approach to a diseased child, while support of the society is an important factor

Laboratory diagnostics of emergency conditions associated with inborn errors of metabolism

Inborn errors of metabolism are a growing group of monogenic hereditary diseases whose pathogenesis may be accounted for by biochemical disorders. The great majority of these diseases may occur as a metabolic crisis at any period of life. For their adequate treatment, fast recognition of the cause of the metabolic disorder is necessary, as well as good collaboration of all health professionals involved in immediate patient healthcare. On the path to final diagnosis, it is advisable to consult specialised centres in order to select appropriate diagnostic tests and procedures

Challenges and possibilities of selective laboratory diagnostics of neuronal ceroid lipofuscinosis types 1 and 2 in Croatia

Neuronske ceroidne lipofuscinoze su jedna od najučestalijih neurometaboličkih poremećaja u djece. Sve veće dijagnostičke i terapijske mogućnosti, prvenstveno za ceroidnu lipofuscinozu tipa 2, izazov su za pravodobno postavljanje dijagnoze koja je uglavnom povezana s većim dijagnostičkim centrima. Rana dijagnoza ove bolesti presudna je radi osiguranja optimalne skrbi za djecu i njihove obitelji, ali je izazovna prvenstveno zbog nedostatka svijesti o bolesti i nespecifičnosti početnih simptoma. Cilj je ovog teksta pružiti osnovne informacije o dostupnosti selektivne laboratorijske dijagnostike za ceroidnu lipofuscinozu tipa 1 i tipa 2 u Republici Hrvatskoj te ove mogućnosti ponuditi i pedijatrijskim neurolozima okolnih zemalja.Neuronal ceroid lipofuscinoses are one of the most common neurometabolic disorders in children. Enhanced diagnostic and therapeutic possibilities, primarily for ceroid lipofuscinosis type 2, presents a challenge for timely diagnosis, which is mostly off ered in large diagnostic centres. Early diagnosis of this disease is of utmost importance to ensure optimum care for children and their families, but is challenging mainly due to the lack of awareness of the disease, along with its nonspecifi c initial symptoms. The aim of this article is to provide basic information on the availability of selective laboratory diagnostics for ceroid lipofuscinosis types 1 and 2 in Croatia and off er such diagnostics also to paediatric neurologists from neighbouring countries

Laboratorijska dijagnostika neuronske ceroidne lipofuscinoze tipa 2 (CLN2) iz suhe kapi krvi na filtarskom papiru i leukocita

Neuronska ceroidna lipofuscinoza tipa 2 (CLN2; Battenova bolest tipa 2; OMIM, #204500) prouzročena je nedostatnom aktivnošću lizosomske serin-proteaze tripeptidil-peptidaze (TPP1). Bolest je progresivnog tijeka, a klinički simptomi najčešće se pojavljuju između druge i četvrte godine života. Bez pravodobno postavljene dijagnoze i uvođenja odgovarajućeg liječenja dolazi do brzog propadanja motoričkih i kognitivnih funkcija. Laboratorijski selektivni probir započinje mjerenjem aktivnosti enzima TPP1 iz uzorka suhe kapi krvi na filtarskom papiru, a svaka snižena aktivnost mora se potvrditi mjerenjem u homogenatu leukocita. Aktivnost TPP1 mjeri se interno razvijenom (engl. in house) fluorimetrijskom metodom za koju je nužno u svakom laboratoriju uspostaviti referentne intervale. Naši referentni rasponi TPP1 iz uzoraka suhe kapi krvi jesu 58,8 (± 12,8) μmol/isječku/sat, a iz leukocita 624,8 (± 153,4) nmol/sat/mg proteina. Konačna je potvrda dijagnoze nalaz patogenih mutacija u genu TPP1/CLN2. Postavljanje rane kliničke sumnje na CLN2 predstavlja izazov u vremenu kada je dostupna rana laboratorijska dijagnostika kao i odgovarajući pristup liječenju

Laboratorijska dijagnostika neuronske ceroidne lipofuscinoze tipa 2 (CLN2) iz suhe kapi krvi na filtarskom papiru i leukocita

Neuronska ceroidna lipofuscinoza tipa 2 (CLN2; Battenova bolest tipa 2; OMIM, #204500) prouzročena je nedostatnom aktivnošću lizosomske serin-proteaze tripeptidil-peptidaze (TPP1). Bolest je progresivnog tijeka, a klinički simptomi najčešće se pojavljuju između druge i četvrte godine života. Bez pravodobno postavljene dijagnoze i uvođenja odgovarajućeg liječenja dolazi do brzog propadanja motoričkih i kognitivnih funkcija. Laboratorijski selektivni probir započinje mjerenjem aktivnosti enzima TPP1 iz uzorka suhe kapi krvi na filtarskom papiru, a svaka snižena aktivnost mora se potvrditi mjerenjem u homogenatu leukocita. Aktivnost TPP1 mjeri se interno razvijenom (engl. in house) fluorimetrijskom metodom za koju je nužno u svakom laboratoriju uspostaviti referentne intervale. Naši referentni rasponi TPP1 iz uzoraka suhe kapi krvi jesu 58,8 (± 12,8) μmol/isječku/sat, a iz leukocita 624,8 (± 153,4) nmol/sat/mg proteina. Konačna je potvrda dijagnoze nalaz patogenih mutacija u genu TPP1/CLN2. Postavljanje rane kliničke sumnje na CLN2 predstavlja izazov u vremenu kada je dostupna rana laboratorijska dijagnostika kao i odgovarajući pristup liječenju

Homocystinuria in adult patients

Klasična homocistinurija je aminoacidopatija prvi put opisana 1962. godine. Nastaje kao posljedica nemogućnosti razgradnje i povećane koncentracije aminokiseline homocisteina u cirkulaciji. Do povećane koncentracije homocisteina u plazmi/serumu i urinu mogu dovesti različiti nasljedni metabolički poremećaji kao i neka stečena stanja. Od nasljednih metaboličkih poremećaja koji dovode do homocisteinemije i homocistinurije najučestalija je autosomno recesivna bolest klasična homocistinurija (McKusick 236200) uzrokovana nedostatkom enzima cistationin beta-sintaze (CBS; EC 4.2.1.22). Ako se ne počne pravodobno liječiti, bolest može dovesti do ozbiljnih komplikacija koje se manifestiraju promjenama na središnjem živčanom sustavu, očima, kostima i krvnim žilama, a poglavito u vidu tromboembolijskih procesa. Novorođenački probir, koji bi prethodio procesu liječenja, ne provodi se u mnogim zemljama, pa tako niti u Republici Hrvatskoj. S postavljanjem dijagnoze u kasnijoj životnoj dobi značajno se kasni zbog nedovoljne osjetljivosti liječnika na postojanje ove bolesti te njenom povezanošću s čitavom lepezom kliničkih simptoma. Bolesnici se dugo upućuju raznim specijalistima koji se posvećuju liječenju pojedinih kliničkih manifestacija, uglavnom bez rezul tata. Bez liječenja osnovne bolesti promjene stalno napreduju. Poseban dijagnostički problem su bolesnici s nedostatkom CBS-a u kojih karakteristična vanjska klinička obilježja nisu prisutna. Homocistein je samo intermitentno povišen, i to u situacijama kad ne uzimaju piridoksin, a najčešće su tromboembolijski događaji jedina manifestacija bolesti. Na osnovi vlastitih iskustava prikazanih u ovom radu, kao i podataka iz dostupne literature, možemo zaključiti da je u bolesnika dječje, adolescentske ili odrasle dobi s visokom ili brzoprogredirajućom miopijom, subluksacijom leća, marfanoidnim izgledom i/ili tromboembolijskim incidentom potrebno izmjeriti koncentraciju homocisteina u plazmi te provesti obiteljski probir.Classical homocystinuria is aminoacidopathy fi rst described in 1962. It results from the inability of degradation and consequential accumulation of the amino acid homocysteine in the circulation. Increased plasma/serum and urine homocysteine levels can be caused by diff erent inherited metabolic disorders or by some acquired conditions. Classical homocystinuria (McKusick 236200) is a pathologic condition that arises from elevated concentrations of homocysteine in the plasma, most frequently due to cystathionine β-synthase defi ciency (CBS; EC 4.2.1.22). If not treated in time, the disease can lead to serious central nervous system, eye, bone and blood vessel complications, mainly thromboembolism. However, newborn screening for homocystinuria is not routinely performed in many countries, including Croatia. In spite of various reasons that may cause delay in the diagnosis of homocystinuria, the predominant one is that physicians often fail to connect a cluster of common symptoms with this rare disease. Patients are referred to various specialists who focus on the treatment of diff erent clinical manifestations of homocystinuria, mostly without success. Without treatment of the underlying disease, chronic complications of homocystinuria progress and patients are jeopardized by sometimes even life-threatening thromboembolism. Patients with CBS defi ciency in whom typical clinical phenotype is absent, represent a particular diagnostic problem, as homocysteine is usually only periodically increased when pyridoxine is omitted from therapy. Within these patients recurrent episodes of thromboembolism are commonly the only clinical feature of homocystinuria. Based on our experience and data from the literature, early recognition of severe or rapidly progressing myopia, subluxation of ocular lenses, ‘marphanoid’ appearance and/or thromboembolism should be an indication for plasma homocysteine measurement and family screening

Spontaneous Perforation of the Small Intestine, a Novel Manifestation of Classical Homocystinuria in an Adult with New Cystathionine b-synthetase Gene Mutations

The clinical picture of classical homocystinuria is diverse. This is the first report of an adult homocystinuric patient with non-traumatic spontaneous small bowel perforation. A 47-year old man presented with abdominal rebound tenderness, hypotension and tachycardia, anemia, and elevated markers of inflammation. Other routine laboratory tests were normal. Abdominal x-ray showed no free air. An emergency laparotomy revealed jejunal perforation in the left upper quadrant. Histologic specimen showed full-thickness nonspecific inflammation of the intestinal wall with granulocytic infiltration, hemorrhage and necrosis. Tuberculosis, actinomycosis and typhus were histologically and clinically excluded. After excluding all known possible causes of perforation, we presumed a causative relationship between homocystinuria and small bowel perforation. It could be hypothesized that connective tissue weakness in homocystinuria is a result of homocysteine interference with recombinant human fibrillin-1 fragments or cross-linking of collagen through permanent degradation of disulfide bridges and lysine amino acid residues in proteins. DNA analysis showed three detectable mutations in the cystathionine beta-synthetase gene, 1278T:c.833T>C, and two new mutations, V372G:c.1133T>G, and D520G:c.1558A>G in the alternatively spliced exon 15

MANAGEMENT GUIDELINES FOR MUCOPOLYSACCHARIDOSIS TYPE VI IN ADULTS

Mukopolisaharidoza tipa VI (Maroteaux-Lamyjev sindrom; MPS VI) progresivna je multisistemska lizosomska bolest nakupljanja. Za bolest su posebno karakteristični nizak rast i koštana displazija. Enzimsko nadomjesno liječenje provodi se lijekom galsulfazom koji se primjenjuje intravenski. To je rekombinantni oblik enzima N-acetilgalaktozamin 4-sulfataze. Liječenje je potrebno započeti odmah nakon postavljanja dijagnoze. Lijek se primjenjuje jedanput na tjedan, a liječenje je doživotno. Zavod za bolesti metabolizma Klinike za unutarnje bolesti KBC-a Zagreb nastavlja s liječenjem bolesnika s MPS-om VI nakon što navrše 18 godina. Stoga je cilj ovog članka predstaviti smjernice za dijagnozu i liječenje odraslih bolesnika s MPS-om VI koje se sastoji od redovite primjene galsulfaze te praćenja brojnih komorbiditeta. Smjernice su sastavili stručnjaci iz Zavoda za bolesti metabolizma Klinike za unutarnje bolesti Kliničkoga bolničkog centra Zagreb, koji je ujedno Referentni centar Ministarstva zdravlja Republike Hrvatske za rijetke i metaboličke bolesti. U izradi smjernica također su sudjelovali pedijatri, radiolozi i biokemičari bez čijeg iskustva i savjeta praćenje i primjereno liječenje ovih bolesnika ne bi bilo moguće. Ove su smjernice prihvaćene na Godišnjoj skupštini Hrvatskog društva za rijetke bolesti Hrvatskoga liječničkog zbora.Mucopolysaccharidosis type VI (Maroteaux-Lamy syndrome, MPS VI) is a progressive multisystemic lysosomal storage disease. Physical symptoms generally include growth retardation, and bone dysplasia. Enzyme replacement therapy is the treatment of choice and is done with recombinant version of enzyme N-acetylgalactosamine 4-sulfatase (galsulfase) which is administered intravenously. The enzyme replacement therapy should be applied once a week as a life–long treatment. Division of metabolic diseases, Department of internal medicine, University Hospital Center Zagreb continues with the treatment of MPS VI patients after they turn 18 years of life and are not treated any more by the pediatricians. The aim of this document is to provide the guidelines for diagnosis and management of adult patients with MPS VI which consists not only of regular galsulfase adiministration, but also of regular follow up and treatment of numerous comorbidities. These guidelines were produced by experts from the Division of metabolic diseases, Department of internal medicine, University Hospital Center Zagreb which is the Referral center for rare and metabolic diseases of the Ministry of Health, Republic of Croatia. The guidelines are result of collaboration with pediatricians, radiologists and biochemists without whose experience and advices appropriate treatment of these patients would not be possible. The guidelines were endorsed by the Croatian society for rare diseases, Croatian Medical Association

Pompeova bolest – smjernice za dijagnozu i liječenje odraslih bolesnika [Pompe disease - guidelines for diagnosis and management of adult patients]

These guidelines provide a short summary of recommendations on Pompe disease, how to diagnose this disease, management of adult patients with this disease, follow-up of the patients and recommendations on therapy and genetic testing. Early diagnosis and management of patients with Pompe disease requires a multidisciplinary approach of several different experts. These guidelines were produced by the Division of Metabolic Diseases, Department of Internal Medicine, University Hospital Center Zagreb which is a Referral expert center for rare and metabolic diseases of the Ministry of Health of the Republic of Croatia. They were endorsed by the Croatian Society for Rare Diseases, Croatian Medical Association.These are the first guidelines published in Croatia on diagnosis, treatment and follow-up of Pompe disease

POMPE DISEASE – GUIDELINES FOR DIAGNOSIS AND MANAGEMENT OF ADULT PATIENTS

Ove smjernice daju kratke naputke o Pompeovoj bolesti: kako dijagnosticirati, liječiti i pratiti bolesnike koji boluju od ove rijetke lizosomske bolesti nakupljanja. Rano postavljanje dijagnoze i liječenje bolesnika s Pompeovom bolesti zahtijevaju multidisciplinarni pristup niza stručnjaka. Smjernice su sastavili stručnjaci koji imaju iskustvo u radu s bolesnicima oboljelima od rijetkih bolesti metabolizma i plod su iskustva rada s rijetkim bolestima u Zavodu za bolesti metabolizma Klinike za unutarnje bolesti, KBC Zagreb, Referentnog centra Ministarstva zdravlja i socijalne skrbi Republike Hrvatske za rijetke i metaboličke bolesti. Smjernice su prihvaćene na Godišnjoj skupštini Hrvatskog društva za rijetke bolesti Hrvatskoga liječničkog zbora. Radi se o prvim takvim smjernicama u Republici Hrvatskoj pa se ovom inicijativom (uz smjernice o Gaucherovoj i Fabryjevoj bolesti) Hrvatska priključuje ostalim europskim državama koje su donijele smjernice iz područja rijetkih bolesti metabolizma.These guidelines provide a short summary of recommendations on Pompe disease, how to diagnose this disease, management of adult patients with this disease, follow-up of the patients and recommendations on therapy and genetic testing. Early diagnosis and management of patients with Pompe disease requires a multidisciplinary approach of several different experts. These guidelines were produced by the Division of Metabolic Diseases, Department of Internal Medicine, University Hospital Center Zagreb which is a Referral expert center for rare and metabolic diseases of the Ministry of Health of the Republic of Croatia. They were endorsed by the Croatian Society for Rare Diseases, Croatian Medical Association.These are the first guidelines published in Croatia on diagnosis, treatment and follow-up of Pompe disease