POS0472 COMPARATIVE METABOLOMIC ANALYSIS OF SERUM SAMPLES FROM PATIENTS WITH COINCIDENTAL RHEUMATOLOGICAL AND MALIGNANT DISEASES

Background:

Rheumatic and musculoskeletal diseases (RMDs) and malignancies are both caused by a dysfunctional immune system and the probability of their coincidence in one individual is rising due to advances in cancer treatment and demographic changes. However, the lack of understanding of the complex interrelationship of both conditions often leads to undertreatment and high level of suffering in affected patients. Herein, the MalheuR project breaks new ground by systematic analysis of concomitant malignant and rheumatic diseases and closes the knowledge gaps on the clinical and molecular level.

Objectives:

To enable early diagnosis of concomitant malignancy and/or identification of patients at risk in the future, changes in serum metabolome were explored in order to create a diagnostic classification model.

Methods:

Serum samples from patients with concomitant RMD and cancer or obligate precancerous lesions (n=78, breast cancer (23), melanoma (14), MGUS (12), prostate cancer (8) and others (21)) were collected as a pilot study within the MalheuR project, a registry-based study initiated in 2018 at the university hospital Heidelberg, Germany. The following groups were defined by the underlying RMD: rheumatoid arthritis (n=42), psoriasis arthritis (n=23), spondylarthritis (n=9) and systemic lupus erythematosus (n=4). RMD patients without any malignancies were used as controls (n=280: 122 RA, 81 PsA, 46 SpA, 31 SLE).

Samples were analyzed by 1H NMR spectroscopy. For all samples, regular 1H acquisition with presaturation and Carr-Purcell-Meiboom-Gill (CPMG) spectra were acquired using a 600 MHz Bruker NMR spectrometer. Spectra were processed with TopSpin using 0.2 Hz of line broadening and manual phasing. Molar concentrations of 26 metabolites were acquired by integration of NMR spectra. With GraphPad Prism, univariate and ANOVA statistical analysis was performed to find significant differences between each malignant group and their control group as well as between all four malignant groups.

Results:

Mean disease duration was 11.8 ±10.5 years for cancer and 12.8±10.8 years for RMDs since diagnosis. 1.4% received cancer treatment (6.4% of malignancy group), 69.3% csDMARDs, 42.3% b/tsDMARDs and 46.4% glucocorticoids at the time of sample collection.

Most metabolites tested were significantly lower in the malignancy groups versus associated controls: Concentrations of amino acids V and L were significantly reduced in all malignancy samples. Additionally, T, D, N, Q, E, A, I were altered in RA, SpA and PsA, changes in G were seen in RA, PsA and SLE and P was altered in RA and PsA only. Furthermore, lower concentrations of short chain fatty acids and tricarboxylic acid cycle intermediates were present in the malignancy groups. In no case was a metabolite concentration significantly higher in the malignancy group than in the associated control. When comparing the metabolome within the four malignancy groups, only the concentrations of creatine, threonine and isoleucine were found higher in RA patients with malignancy.

Conclusion:

Significant differences between the metabolomic fingerprints of RMD patients with and without malignancies could be observed. These changes might be characteristic for cancer burden, as in most cases the underlying RMD was not relevant when comparing the concentrations between the malignancy groups. Our results may promote understanding of the interrelationships of both disease entities as well as prove useful as biomarkers for diagnostic and therapeutic purposes.

Acknowledgements:

Grant/research support from medical faculty (Olympia Morata Programme) and foundations commission (Herbert Daus estate) of University of Heidelberg

Disclosure of Interests:

None declared

POS0293 TRheuMa REGISTRY PROVIDES FIRST EVIDENCE OF DIFFERENT COURSE OF RHEUMATIC IMMUNE-RELATED ADVERSE EVENTS AND TUMOUR RESPONSE RATES DEPENDING ON THE TUMOUR ENTITY

Background:

Rheumatic immune-related adverse events (irAE) are associated with a better tumour response to immune checkpoint inhibitors (ICI). In contrast to other irAEs, their potentially chronic course may require long-term immunosuppressive treatment.

Objectives:

Our registry-based study analyses real-world data on the characteristics and outcome of rheumatic irAEs and underlying malignancy. Herein, we present first evidence that these parameters and the optimal clinical management may differ depending on the tumour entity.

Methods:

The TRheuMa registry is a prospective long-term observational study of a patient cohort suffering from rheumatic side effects of cancer therapies with focus on ICI. It is part of the MalheuR project initiated in July 2018 at the University Hospital Heidelberg to explore interrelations of malignancies and RMDs.

Results:

64 patients were recruited due to a rheumatic irAE under ICI treatment (nivolumab n=30, pembrolizumab n=33, ipilimumab n=12, PD-L1i n=5, ipi/nivo n=10) with a follow-up of up to 30 months. Of these, 47% had NSCLC and 41% melanoma. In local cohorts of patients receiving ICI, 4% of NSCLC (n total=888) and 13% of melanoma (n total=195) developed a rheumatic irAE. 7% of NSCLC and 23% of melanoma patients experienced a flare of a pre-existing RMD. De novo irAE mostly resembled phenotypes of spondyloarthritis both in NSCLC (43%) as well as in melanoma patients (33%). CRP levels were increased in 83% of NSCLC and 71% of melanoma patients. Almost all irAE patients showed autoantibody negativity and signs of inflammation in ultrasound examination (96%). Comparison of best responses to treatment in patients with and without rheumatic irAE in melanoma and without any irAE in NSCLC patients were as following: Complete remission (CR) in 48% vs. 4% of melanoma patients and partial remission (PR) in 68% vs. 41% of NSCLC patients. In accordance with our severity-based treatment algorithm, 25% of the melanoma patients in CR and 16% of the NSCLC patients in PR needed add-on DMARDs for sufficient irAE-treatment. ICI-treatment was discontinued in 7 cases (17% NSCLC, 8% melanoma)

Conclusion:

Prospective real-world data from the TRheuMa-registry provide first evidence that rheumatic irAE have distinct characteristics depending on the underlying malignancy. Oncological outcome was better with rheumatic irAE than in their absence and this effect was more pronounced in melanoma patients despite a larger use of immunosuppressants for irAE-treatment.

Disclosure of Interests:

Leonore Diekmann: None declared, Lea Daniello: None declared, Julia Kunz: None declared, Jan Leipe Consultant of: Pfizer; Novartis; Honoraria (self), Abbvie; Astra Zeneca; BMS; Celgene; Hospira; Janssen-Cilag; Gilead; LEO Pharma; Lilly; MSD; Roche; Sanofi; UCB., Grant/research support from: Research grant/Funding (self): Pfizer; Novartis; Honoraria (self), Hanns-Martin Lorenz Consultant of: Abbvie; BMS; MSD; Pfizer; Celgene; Roche; Chugai; Medac; GSK; Honoraria (self), Novartis; UCB; Janssen-Cilag; Astra Zeneca; Lilly, Grant/research support from: Research grant/Funding (institution): Abbvie; BMS; MSD; Pfizer; Celgene; Roche; Chugai; Medac; GSK; Honoraria (self), Research grant/Funding (institution), Novartis; UCB; Janssen-Cilag; Astra Zeneca; Lilly; Research grant/Funding (institution): Baxter; SOBI; Biogen; Actelion; Mundipharma; Bayer Vital; Octapharm; Sanofi; Hexal; Thermo Fischer; Shire., Jessica Hassel Consultant of: MDS; Honoraria (self): Roche; Novartis; Pierre Fabre., Grant/research support from: BMS; Honoraria (self), Karin Jordan Consultant of: Advisory/Consultancy: Amgen; Merck; MSD; Riemser; Helsinn; Tesaro; Kreussler; Voluntis; Pfizer; Pomme-med; Hexal., Petros Christopoulos Consultant of: advisory board/lecture fees from AstraZeneca, Boehringer Ingelheim, Chugai, Novartis, Pfizer, Roche, Takeda., Grant/research support from: research funding from AstraZeneca, Novartis, Roche, Takeda, Karolina Benesova Grant/research support from: Foundations and Awards” commission of the University of Heidelberg: University of Heidelberg; AbbVie; Novartis; Rheumaliga Baden-Württemberg e.V

AB1021 CHARACTERISTICS AND MANAGEMENT OF RHEUMATIC MANIFESTATION UNDER ESTROGEN RECEPTOR-TARGETING CANCER THERAPIES, DATA FROM A PROSPECTIVE REGISTRY

Background:

The knowledge about interdependencies between rheumatic manifestations and malignancies is limited. Further, reliable data on the occurrence of rheumatic symptoms as side effects of specific cancer therapies beyond checkpointinhibitor-induced immune-related adverse events are sparse. In this regard, although arthralgia under estrogen receptor-targeting therapies (aromatase inhibitors and the estrogen receptor modulator tamoxifen) has been frequently reported in oncological clinical trials and case reports, prospective data including an assessment of rheumatic manifestations by rheumatologists are lacking.

Objectives:

To contribute to a better understanding of interdependencies between rheumatic manifestations and cancer/ estrogen blockade and potentially improve the management of both entities, pilot data were analysed.

Methods:

Data on characteristics and treatment of rheumatic manifestations and cancer as well as their timely association were systematically, prospectively collected and analysed in the MalheuR (´malignancy and rheumatic disease´) registry, a long-term, observational study designed to study patients suffering from concomitant rheumatic disease and malignancy and/or premalignant lesions.

Results:

We identified 11 patients with rheumatic manifestations under estrogen receptor-targeting therapies (3 anastrozol, 4 letrozol, 8 tamoxifen) as part of breast cancer treatment. In addition to breast cancer one patient had a lymphoma 3 years after and another patient had a non-small cell lung cancer 2 years before breast cancer diagnosis. The patients had different cancer stages (5 IA, 3 IIA, 1 IIB, and 1 IVA). Their mean age at cancer diagnosis was 60.4 ± 11.6 years and all patients are females. The time interval between diagnosis of cancer and onset of systemic/ rheumatic symptoms was 49.5 ± 34.0 months. Of interest, the time interval between onset of rheumatic symptoms and first assessment by a rheumatologist was 16.9 ± 22.3 months. The following systemic and rheumatic symptoms were reported: arthralgia in 10, arthritis in 8 (small joints in 5, large joints in 3 affected), morning stiffness (>30 min) in 7, IBP in 1, myalgia in 7, sicca symptoms in 2, fever in 1 (new-onset FMF with heterozygous M694U mutation), class IV glomerulonephritis and polyserositis in 1 (with new-onset SLE) patient(s). Disease burden at baseline was rather high with a mean VAS pain of 65 (±12.9)/100. Laboratory analyses revealed an increased CRP in 6/11 (55%) with a mean of 10.3 ± 8.2 mg/l (<5). Autoantibody positivity was observed for ANAs in 5/10 (50%, titers ranging from 1:80 to 1:160), anti-dsDNA in 1, rheumatoid factor in only 1/10 (10%) patients, none was anti-CCP positive. Before consulting a rheumatologist, patients were treated with NSAR 3/11 (27%), 10/11 systemic glucocorticoids (91%) with an initial dose of 17.5 ± 19.5 mg and intra-articular glucocorticoids 1/11 (9%). Rheumatological assessment lead to initiation of csDMARDs (3/11 MTX, 1/11 SSZ, 1/11 HCQ, 1/11 AZA (later MMF/ rituximab in the SLE patient) 1/11 colchicine) as corticosteroid-sparing agents with good response in the majority of patients.

Conclusion:

Our data demonstrate heterogeneous rheumatic manifestations, partially with severe manifestations beyond arthralgia, so far not reported by oncological studies including follow-up, which might suggest an underreporting. Furthermore, despite close monitoring in tumor aftercare, our data show a considerable delay in referral to a rheumatologist and initiation of suitable treatment. The prospective design of the MalheuR registry enables future validation of our pilot data.

Disclosure of Interests:

Alina Dr. Patroi Consultant of: Advisory board Novartis, Leonore Diekmann: None declared, Hanns-Martin Lorenz Grant/research support from: Consultancy and/or speaker fees and/or travel reimbursements: Abbvie, MSD, BMS, Pfizer, Celgene, Medac, GSK, Roche, Chugai, Novartis, UCB, Janssen-Cilag, Astra-Zeneca, Lilly. Scientific support and/or educational seminars and/or clinical studies: Abbvie, MSD, BMS, Pfizer, Celgene, Medac, GSK, Roche, Chugai, Novartis, UCB, Janssen-Cilag, Astra-Zeneca, Lilly, Baxter, SOBI, Biogen, Actelion, Bayer Vital, Shire, Octapharm, Sanofi, Hexal, Mundipharm, Thermo Fisher., Consultant of: see above, Bernhard. Kraemer: None declared, Karolina Benesova Grant/research support from: Study grants for SCREENED study by Abbvie, Novartis and Rheumaliga Baden-Württemberg, Consultant of: One-time participation in Novartis advisory board., Jan Leipe Grant/research support from: Consultancy and speaker fees: Abbvie, AstraZeneca, BMS, Celgene, Hospira, Janssen-Cilag, LEO Pharma, Lilly, MSD, Novartis, Pfizer, Roche, Sanofi, UCB. Scientific support: Novartis, Pfizer., Consultant of: Consultancy and speaker fees: Abbvie, AstraZeneca, BMS, Celgene, Hospira, Janssen-Cilag, LEO Pharma, Lilly, MSD, Novartis, Pfizer, Roche, Sanofi, UCB. Scientific support: Novartis, Pfizer., Speakers bureau: Abbvie, AstraZeneca, BMS, Celgene, Hospira, Janssen-Cilag, LEO Pharma, Lilly, MSD, Novartis, Pfizer, Roche, Sanofi, UCB

SAT0578 RHEUMAL REGISTRY PROVIDES FIRST INSIGHTS INTO MUTUAL INTERDEPENDENCIES BETWEEN RHEUMATIC AND MUSCULOSKELETAL DISEASES AND MALIGNANCIES

Background:

Knowledge about interdependencies between rheumatic and musculoskeletal diseases (RMDs) and malignancies is limited on the clinical and molecular level. Particularly, valid prospective data on the timely association of malignancies in patients with RMDs and treatment of the latter are sparse.

Objectives:

Due to the heterogeneous patient population, a registry-based study has been conducted in order to provide insights into mutual interdependencies and novel evidence for suitable clinical management of patients with concomitant RMD and malignancies.

Methods:

The RheuMal registry is a long-term, open-end observational study designed to address the specific situation of patients suffering from concomitant RMD and concomitant malignancy and/or premalignant conditions. The RheuMal registry is one of the three subregistries of the MalheuR project, a registry-based study initiated in July 2018 at the at the university hospital Heidelberg, Germany.

Results:

Data from the RheuMal registry (n=404) show an earlier onset of gender-specific cancers and malignant melanoma in RMD patients compared to data from the German Cancer Registry Data of the Robert-Koch-Institute: compared to the reference population, in RMD patients breast cancer (n=32) occurred 5.3 years and prostate cancer (n=16) 3.3 years earlier. Onset of malignant melanoma was 2.4 years earlier in females (n=9) and 1.1 years in males (n=7) with concomitant RMD. The mean latency between the initial diagnosis of the RMD and the later occurring malignant condition was 10.2 years. The diagnosis of the malignancy frequently led to a change or interruption of disease-modifying antirheumatic therapy in RMDs.

Conclusion:

The RheuMal registry offers first insights into interdependencies between RMDs and malignancies based on demographic data, disease characteristics, clinical management and outcome as well as correlation of specific diagnoses and therapies. The earlier onset of gender-specific cancers and malignant melanoma suggests differences in the epidemiology and course of the malignant disease in RMD patients compared to a healthy reference population, suggesting interdependency between the two disease entities. Future research will focus on further understanding of this interdependency und the underlying molecular mechanisms.

Disclosure of Interests:

Karolina Benesova Grant/research support from: Study grants for SCREENED study by Abbvie, Novartis and Rheumaliga Baden-Württemberg, Consultant of: One-time participation in Novartis advisory board., Leonore Diekmann: None declared, Maria Czaja: None declared, Karin Jordan Consultant of: Consultancy and/or speaker fees: MSD, Merck, Amgen, Hexal, Riemser, Helsinn, Tesaro, Kreussler, Voluntis, Pfizer, Pomme-med., Jan Leipe Grant/research support from: Consultancy and speaker fees: Abbvie, AstraZeneca, BMS, Celgene, Hospira, Janssen-Cilag, LEO Pharma, Lilly, MSD, Novartis, Pfizer, Roche, Sanofi, UCB. Scientific support: Novartis, Pfizer., Consultant of: Consultancy and speaker fees: Abbvie, AstraZeneca, BMS, Celgene, Hospira, Janssen-Cilag, LEO Pharma, Lilly, MSD, Novartis, Pfizer, Roche, Sanofi, UCB. Scientific support: Novartis, Pfizer., Speakers bureau: Abbvie, AstraZeneca, BMS, Celgene, Hospira, Janssen-Cilag, LEO Pharma, Lilly, MSD, Novartis, Pfizer, Roche, Sanofi, UCB, Hanns-Martin Lorenz Grant/research support from: Consultancy and/or speaker fees and/or travel reimbursements: Abbvie, MSD, BMS, Pfizer, Celgene, Medac, GSK, Roche, Chugai, Novartis, UCB, Janssen-Cilag, Astra-Zeneca, Lilly. Scientific support and/or educational seminars and/or clinical studies: Abbvie, MSD, BMS, Pfizer, Celgene, Medac, GSK, Roche, Chugai, Novartis, UCB, Janssen-Cilag, Astra-Zeneca, Lilly, Baxter, SOBI, Biogen, Actelion, Bayer Vital, Shire, Octapharm, Sanofi, Hexal, Mundipharm, Thermo Fisher., Consultant of: see above

OP0270 TRHEUMA REGISTRY EXPLORES CHARACTERISTICS AND SUITABLE DIAGNOSTIC AND THERAPEUTIC MANAGEMENT OF RHEUMATIC IMMUNE-RELATED ADVERSE EVENTS (IRAES)

Background:

Reports of rheumatic immune-related adverse events (irAEs) in patients receiving immune checkpoint inhibitors (ICPi) have recently attracted new attention to the complex interrelations of malignancies andrheumatic and musculoskeletal diseases (RMDs). Since those two entities represent two sides of a dysregulated immune response, further research on rheumatic irAEs and mechanisms underlying the better tumor response rates in irAE-affected patients may contribute to a better understanding of the different pathophysiology characterizing tumor and rheumatic disease.

Objectives:

Given the heterogeneity of the patient population with rheumatic irAEs, a registry-based study has been conducted to provide first evidence regarding characteristics of rheumatic irAEs and further insights into the optimal diagnostic and therapeutic management of rheumatic irAEs.

Methods:

The TRheuMa registry is a long-term, open-end observational study of a patient cohort suffering from rheumatic symptoms as a result of ICPi or other cancer therapies. The TRheuMa registry is one of the three subregistries of the MalheuR project, a registry-based study initiated in July 2018 at the at the university hospital Heidelberg to explore interrelations of malignancies and RMDs.

Results:

Over 18 months, 52 of 63 patients in the TRheuMa registry were recruited with a rheumatic irAE under ICPi treatment (pembrolizumab n=21, nivolumab n=28, ipilimumab n=11, durvalumab n=1, atezolizumab n=2, avelumab n=1, history of >1 ICPi n=11). Of the 52 patients, 22 (42.3%) had non-small cell lung cancer and 23 (44.2%) had a melanoma. Eight (15.3%) patients experienced a flare of a preexisting RMD under ICPi treatment. The remaining 44 patients withde novoirAEs were characterized by rheumatoid arthritis-like (20.5%) or polymyalgia rheumatica-like (18.1%) and psoriatic or other spondyloarthritis-like phenotypes (50.0%). However, laboratory findings differed from classical RMDs with elevated CRP-levels in 73.1% particularly in psoriatic arthritis-like, but not necessarily in polymyalgia rheumatica-like irAEs. On the contrary, autoantibody positivity was very rare. The majority of patients (78.8%) showed signs of inflammation upon ultrasound examination.

Based on the severity of signs and symptoms as well as treatment response, we developed a therapeutic algorithm for rheumatic irAEs: non-steroidal anti-inflammatory drugs and/or low dosed glucocorticoids (≤10mg prednisone equivalent) as first treatment step were sufficient for 75% patients, whereas 17.3% required higher dosed glucocorticoids and 11.5% patients required further treatment with a cs- or bDMARD. In two cases ICPi-treatment was discontinued on patients’ request due to the pain and functional impairment caused by the rheumatic irAE, although a satisfactory symptom control was reached in the further course.

Complete remission of cancer was observed in 43.5% of melanoma patients, 66.7% experienced additional severe irAEs in other organ systems.

Conclusion:

Overall, data from the TRheuMa-registry show that rheumatic irAEs mostly resemble classical RMDs, however show distinct characteristics. Our diagnostic and therapeutic management of rheumatic irAEs demonstrated efficacy in the majority of patients. These findings contribute to the further understanding of rheumatic irAEs and malignancies. Future research agenda includes a correlation of irAE severity with tumor response.

Disclosure of Interests:

Karolina Benesova Grant/research support from: Study grants for SCREENED study by Abbvie, Novartis and Rheumaliga Baden-Württemberg, Consultant of: One-time participation in Novartis advisory board., Leonore Diekmann: None declared, Hanns-Martin Lorenz Grant/research support from: Consultancy and/or speaker fees and/or travel reimbursements: Abbvie, MSD, BMS, Pfizer, Celgene, Medac, GSK, Roche, Chugai, Novartis, UCB, Janssen-Cilag, Astra-Zeneca, Lilly. Scientific support and/or educational seminars and/or clinical studies: Abbvie, MSD, BMS, Pfizer, Celgene, Medac, GSK, Roche, Chugai, Novartis, UCB, Janssen-Cilag, Astra-Zeneca, Lilly, Baxter, SOBI, Biogen, Actelion, Bayer Vital, Shire, Octapharm, Sanofi, Hexal, Mundipharm, Thermo Fisher., Consultant of: see above, Karin Jordan Consultant of: Consultancy and/or speaker fees: MSD, Merck, Amgen, Hexal, Riemser, Helsinn, Tesaro, Kreussler, Voluntis, Pfizer, Pomme-med., Jan Leipe Grant/research support from: Consultancy and speaker fees: Abbvie, AstraZeneca, BMS, Celgene, Hospira, Janssen-Cilag, LEO Pharma, Lilly, MSD, Novartis, Pfizer, Roche, Sanofi, UCB. Scientific support: Novartis, Pfizer., Consultant of: Consultancy and speaker fees: Abbvie, AstraZeneca, BMS, Celgene, Hospira, Janssen-Cilag, LEO Pharma, Lilly, MSD, Novartis, Pfizer, Roche, Sanofi, UCB. Scientific support: Novartis, Pfizer., Speakers bureau: Abbvie, AstraZeneca, BMS, Celgene, Hospira, Janssen-Cilag, LEO Pharma, Lilly, MSD, Novartis, Pfizer, Roche, Sanofi, UCB

Functional variants in the sucrase-isomaltase gene associate with increased risk of irritable bowel syndrome

OBJECTIVE

IBS is a common gut disorder of uncertain pathogenesis. Among other factors, genetics and certain foods are proposed to contribute. Congenital sucrase-isomaltase deficiency (CSID) is a rare genetic form of disaccharide malabsorption characterised by diarrhoea, abdominal pain and bloating, which are features common to IBS. We tested sucrase-isomaltase (SI) gene variants for their potential relevance in IBS.

DESIGN

We sequenced SI exons in seven familial cases, and screened four CSID mutations (p.Val557Gly, p.Gly1073Asp, p.Arg1124Ter and p.Phe1745Cys) and a common SI coding polymorphism (p.Val15Phe) in a multicentre cohort of 1887 cases and controls. We studied the effect of the 15Val to 15Phe substitution on SI function in vitro. We analysed p.Val15Phe genotype in relation to IBS status, stool frequency and faecal microbiota composition in 250 individuals from the general population.

RESULTS

CSID mutations were more common in patients than asymptomatic controls (p=0.074; OR=1.84) and Exome Aggregation Consortium reference sequenced individuals (p=0.020; OR=1.57). 15Phe was detected in 6/7 sequenced familial cases, and increased IBS risk in case-control and population-based cohorts, with best evidence for diarrhoea phenotypes (combined p=0.00012; OR=1.36). In the population-based sample, 15Phe allele dosage correlated with stool frequency (p=0.026) and Parabacteroides faecal microbiota abundance (p=0.0024). The SI protein with 15Phe exhibited 35% reduced enzymatic activity in vitro compared with 15Val (p<0.05).

CONCLUSIONS

SI gene variants coding for disaccharidases with defective or reduced enzymatic activity predispose to IBS. This may help the identification of individuals at risk, and contribute to personalising treatment options in a subset of patients.

Structural determinants for transport of lactase phlorizin-hydrolase in the early secretory pathway as a multi-domain membrane glycoprotein

BACKGROUND

Lactase phlorizin-hydrolase (LPH) is a membrane anchored type I glycoprotein of the intestinal epithelium that is composed of four homologous structural domains. The role of each distinct domain in the intramolecular organization and function of LPH is not completely understood.

METHODS

Here, we analyzed the early events of LPH biosynthesis and trafficking by directed restructuring of the domain compositions.

RESULTS

Removal of domain I (LPH∆1) results in a malfolded ER-localized protein. By contrast, LPH without domain II (LPH∆2) is normally transported along the secretory pathway, but does not dimerize nor is enzymatically active. Interestingly a polypeptide stretch in domain II between L⁷³⁵-R⁸⁶⁸ exerts an intriguing role in modulating the trafficking behavior of LPH and its biological function. In fact, association of this stretch with transport-competent LPH chimeras results in their ER-arrest or aberrant trafficking. This stretch harbors a unique N-glycosylation site that is responsible for LPH retention in the ER via association with calnexin and facilitates proper folding of domains I and III before ER exit of LPH. Notably, a similar N-glycosylation site is also found in domain IV with comparable effects on the trafficking of LPH-derived molecules.

CONCLUSIONS

Our study provides novel insights into the intramolecular interactions and the sequence of events involved in the folding, dimerization and transport of LPH.

GENERAL SIGNIFICANCE

Elucidation of the structural-functional relevance of the domains in pro-LPH is crucial in unravelling and understanding the molecular basis of carbohydrate malabsorption disorders that are associated with lactase deficiency or lactase malfunction.

The Diverse Forms of Lactose Intolerance and the Putative Linkage to Several Cancers

Lactase-phlorizin hydrolase (LPH) is a membrane glycoprotein and the only β-galactosidase of the brush border membrane of the intestinal epithelium. Besides active transcription, expression of the active LPH requires different maturation steps of the polypeptide through the secretory pathway, including N- and O-glycosylation, dimerization and proteolytic cleavage steps. The inability to digest lactose due to insufficient lactase activity results in gastrointestinal symptoms known as lactose intolerance. In this review, we will concentrate on the structural and functional features of LPH protein and summarize the cellular and molecular mechanism required for its maturation and trafficking. Then, different types of lactose intolerance are discussed, and the molecular aspects of lactase persistence/non-persistence phenotypes are investigated. Finally, we will review the literature focusing on the lactase persistence/non-persistence populations as a comparative model in order to determine the protective or adverse effects of milk and dairy foods on the incidence of colorectal, ovarian and prostate cancers.

Congenital lactose intolerance is triggered by severe mutations on both alleles of the lactase gene

Background

Congenital lactase deficiency (CLD) is a rare severe autosomal recessive disorder, with symptoms like watery diarrhea, meteorism and malnutrition, which start a few days after birth by the onset of nursing. The most common rationales identified for this disorder are missense mutations or premature stop codons in the coding region of the lactase-phlorizin hydrolase (LPH) gene. Recently, two heterozygous mutations, c.4419C > G (p.Y1473X) in exon 10 and c.5387delA (p.D1796fs) in exon 16, have been identified within the coding region of LPH in a Japanese infant with CLD.

Methods

Here, we investigate the influence of these mutations on the structure, biosynthesis and function of LPH. Therefore the mutant genes were transiently expressed in COS-1 cells.

Results

We show that both mutant proteins are mannose-rich glycosylated proteins that are not capable of exiting the endoplasmic reticulum. These mutant proteins are misfolded and turnover studies show that they are ultimately degraded. The enzymatic activities of these mutant forms are not detectable, despite the presence of lactase and phlorizin active sites in the polypeptide backbone of LPH-D1796fs and LPH-Y1473X respectively. Interestingly, wild type LPH retains its complete enzymatic activity and intracellular transport competence in the presence of the pathogenic mutants suggesting that heterozygote carriers presumably do not show symptoms related to CLD.

Conclusions

Our study strongly suggests that the onset of severe forms of CLD is elicited by mutations in the LPH gene that occur in either a compound heterozygous or homozygous pattern of inheritance.

Renal excretion of calcium and phosphorus in premature infants with incipient late metabolic acidosis

BACKGROUND

Premature infants receiving alimentation with cow milk-based formulas run a considerably high risk of incipient late metabolic acidosis, an early stage developing of manifest late metabolic acidosis. Is bone metabolism involved in pathophysiologic mechanisms characterizing this early stage of retention acidosis?

METHODS

Urinary ionography was performed in 10 premature infants with spontaneous development of incipient late metabolic acidosis (indicated by urine pH < 5.4 on 2 consecutive days) and 10 pair-matched premature infants with normal values of urine pH; both groups were receiving full oral nutrition with the same standard formula. Moreover, in 37 premature infants with incipient late metabolic acidosis who were randomly allocated to oral therapy with 2 mmol. kg(-1). d(-1) of either NaHCO 3 or NaCl over a period of 7 days, urinary excretion of calcium and phosphorus was assessed on day 1 and day 7.

RESULTS

Incipient late metabolic acidosis was accompanied by increased phosphaturia in premature infants receiving full oral nutrition. Seventeen premature infants receiving NaCl therapy (19 treatment periods) showed increased calciuria from day 1 to day 7, whereas, in 20 premature infants receiving NaHCO 3 therapy (23 treatment periods), calcium or phosphorus excretion in urine did not increase.

CONCLUSIONS

The data of urinary calcium and phosphorus excretion in premature infants support the hypothesis that bone mineralization may already be impaired in the early stage of incipient late metabolic acidosis.

Minimal-invasive approach to study pulmonary, metabolic and renal responses to alimentary acid-base changes in conscious rabbits

BACKGROUND

Systemic acid-base balance is maintained by the complex interplay of renal and pulmonary control functions and metabolic adaptations, whereby intake and mineral composition of feed are important factors.

AIM OF THE STUDY

It was intended to explore the role of alimentary acid-base load and carbonic anhydrase activity for regulatory responses of renal, pulmonary or metabolic origin in rabbits as typical herbivores.

METHODS

Sixty-eight conscious male rabbits (about 3.5 kg) were kept in a metabolic cage, to determine daily water intake, urine excretion and food consumption. Different groups were fed either alkali-rich rabbit standard pellets, or modified rabbit chow with low Ca++-content, or a special diet with very low alkali content, or standard food together with a low oral dose (about 20 mg x kg(-1) x d(-1)) acetazolamide. Samples from the central ear artery were analyzed for blood gases (PaO2, PaCO2), pHa, base excess (BE) and actual bicarbonate (HCO3a-). The metabolic CO2 production (VCO2 STPD) was determined, to calculate alveolar ventilation (VA BTPS). Anaerobically collected urine was analyzed for pHu and for concentrations of bicarbonate/carbonate (HCO3-/CO3--), ammonium (NH4+), and phosphate.

RESULTS

1) Systemic BE was not affected by alimentary alkali load, either varied spontaneously by standard food intake or by the low-Ca++ diet, and decreased only slightly on the low-alkali diet, but distinctly upon carbonic anhydrase inhibition. 2) Under all conditions of alimentation, PaCO2 was closely correlated with BE without a detectable set-point, the normal-range variability of BE being sufficient to elicit corresponding changes in VA. In contrast, acetazolamide led to much lower values of PaCO2 than predicted by the reference PCO2/BE relationship, being primarily caused by significant reductions in VCO2 (> 20%). 3) Prior to other systems, renal base excretion, normally being high on species-adapted standard chow, closely followed any variation of alimentary alkali load and approached zero upon the low-alkali diet. It was, however, not significantly influenced by carbonic anhydrase (CA) inhibition on alkalirich alimentation.

CONCLUSIONS

Blood acid-base balance in rabbits is maintained over a wide range of alimentary alkali load by effective adaptation of renal base excretion, independent of CA activity. Ventilatory pH control is perpetuated even in the normal range of BE, provided metabolic rate is not impaired, e. g., by CA inhibition. These results may help one understand the different manifestations of acid-base disorders in body fluids under clinical conditions.

[3-hydroxy-3-methylglutaraciduria (case report of a female Turkish sisters with 3-hydroxy-3- methylglutaryl-Coenzyme A lyase deficiency]

3-Hydroxy-3-methylglutaric aciduria is a rare inborn error of metabolism, caused by reduced enzyme activity of the intramitochondrial 3-hydroxy-3-methylglutaryl-CoA lyase. We describe two turkish sisters with this disease. In the older sister clinical symptoms with lethargy, convulsions, metabolic acidosis, hypoglycemia and hyperammonemia lead to the diagnosis. The younger sister was diagnosed prenatally. The clinical course of our patients is compared with those reported in the literature with respect to clinical symptoms, differential diagnosis and therapeutic regimens.

[Trisomy of the short arm of chromosome 10p; description of a female patient with de novo duplication 10p11.2-15]

Trisomy 10p is a rare chromosomal syndrome, characterized by craniofacial abnormalities, malformations of organs and skeleton, and impaired psychomotor development. In most of the cases partial trisomy 10p results of a balanced translocation or inversion, the mother being carrier of the structural abnormality. Only eight of 63 patients with trisomy 10p found in a literature survey present a de novo trisomy. 17 cases show a pure trisomy 10p without an associated deficiency of any other chromosome segment. We report a female patient with an interchromosomal de novo duplication 10p11.2-->15, demonstrating typical clinical signs like craniofacial abnormalities, oral cleft, club foot, seizures, and a severe delay of psychomotor development.

[Polysaccharide specific humoral immunodeficiency in ectodermal dysplasia. Case report of a boy with two affected brothers]

We report a now three year old male patient with ectodermal dysplasia and a polysaccharide specific humoral immunodeficiency. Immunological investigations showed compromised production of IgA, IgM, and IgG2. Isohaemagglutinins still were not detectable at the age of three years. Repeated vaccination with polyvalent pneumococcal polysaccharide vaccine did not result in production of specific antibodies. Two brothers showed clinical signs of ectodermal dysplasia. The elder brother died from pneumococcal sepsis at the age of 3 years. The younger brother suffers from chronic inflammatory gastrointestinal disease with ulcerations in all parts of the gastrointestinal system. Thus, a possible association between polysaccharide specific humoral immunodeficiency and ectodermal dysplasia may be considered.

Modified cow's milk formula with reduced renal acid load preventing incipient late metabolic acidosis in premature infants

BACKGROUND

Premature infants receiving alimentation with cow's milk formulas are at a considerably high risk of developing incipient late metabolic acidosis, an early stage in the development of manifest late metabolic acidosis. Is it possible to reduce this risk by modification of the composition of a standard formula?

METHODS

The mineral composition of a cow's milk preterm formula A was modified (formula B) with the aim of reducing the alimentary load to that of human milk. 160 premature infants were fed either mother's milk (n = 50) or the modified formula B (enriched with sodium and potassium) (n = 110), and their urine pH was tested twice a week. Randomly collected subgroups of infants were studied in detail for nutrient balances. The results were compared with earlier observations of 282 premature infants fed either mother's milk (n = 28) or the standard formula A (n = 254).

RESULTS

Incipient late metabolic acidosis was observed in nine of 78 premature infants receiving mother's milk, 53 of 254 premature infants receiving the standard formula A, and only one of 110 premature infants fed the modified formula B. Net acid excretion was 0.58 mmol/kg/day in 11 premature infants receiving alimentation with the modified formula B compared with 1.73 mmol/kg/day in 23 premature infants fed formula A. This reduction was mainly due to an increased alkali excess (sodium + potassium-chloride) in intake and urine.

CONCLUSIONS

Reduction of renal acid load with the modified formula B had a preventive effect on the rate of development of incipient late metabolic acidosis in premature infants.

Alkali therapy versus sodium chloride supplement in low birthweight infants with incipient late metabolic acidosis

Two hundred and eighty-two patients with birthweights below 2.0 kg were routinely screened for spontaneous development of maximum renal acid stimulation (urine-pH < 5.4). Sixty episodes in 53 patients of incipient late metabolic acidosis (urine pH < 5.4 on 2 consecutive days) were randomly allocated to oral therapy with 2 mmol/kg/day of either NaHCO3 or NaCl for 7 days. All 27 patients on NaHCO3 therapy, but only 15 from 26 patients on NaCl therapy, showed an increase in urine pH values, combined with a relatively high gain in body weight and a tendency to increased N-assimilation. Eleven patients on NaCl therapy showed persistent maximal renal acid stimulation on all 7 days with possibly lower weight gain and no clear change in N-assimilation. Thus, in patients with incipient late metabolic acidosis, NaCl therapy is not as beneficial as NaHCO3 therapy.

Urinary excretion of lactose and oligosaccharides in preterm infants fed human milk or infant formula

At present, not much is known about the absorption and metabolism of human milk (HM) oligosaccharides in term and preterm infants. We investigated the renal excretion of lactose and complex oligosaccharides in preterm infants fed HM (n = 9, mean actual body weight 2290 g) or a cow's milk-based infant formula (n = 9, mean actual body weight 2470 g). We found that the renal excretion of lactose in HM-fed infants was slightly lower than in formula-fed infants (14.0 +/- 7.4 versus 20.4 +/- 8.7 mg kg-1 day-1, mean +/- SD). The excretion of neutral sugars deriving from oligosaccharides was similar in HM-fed and formula-fed infants (3.8 +/- 2.1 versus 2.9 +/- 0.9 mg kg-1 day-1); the difference between means was not statistically significant. The separation and characterization of oligosaccharides by high-pH anion exchange chromatography with pulsed amperometric detection (HPAE-PAD) and subsequent analysis by fast atom bombardment-mass spectrometry (FAB-MS) revealed a more complex pattern in HM-fed infants compared to the formula-fed group. Lactose-derived oligosaccharides characteristic for HM (e.g. lacto-N-tetraose, and lacto-N-fucopentaoses I and II) were excreted in HM-fed but not in formula-fed infants. These results indicate that nutrition has a significant impact on the oligosaccharide composition in urine of preterm infants.

[Neonatal hypoglycemia in congenital isolated aplasia of the adenohypophysis. A case report]

We report a female newborn with prolonged neonatal hypoglycaemia and vomiting. Endocrinologic studies demonstrated the absence of the anterior pituitary hormones ACTH, STH, LH, FSH, and PRL while TSH basal secretion as well as TSH stimulation were normal at the age of 2 months. Magnetic resonance imaging showed aplasia of the anterior pituitary and a nodular ectopic posterior lobe. Substitution with prednisone resulted in normalization of blood glucose values with clinical improvement of the patient. At the age of 8 months the patient was started on recombinant human growth hormone due to poor growth; with 10 months decrease of thyrotropin secretion resulted in additional thyroxine replacement therapy.

[Supplementation of premature infant nutrition with calcium and phosphor for improving mineral supply of premature and small-for-gestational age newborn infants]

A standard preterm formula was supplemented with calcium (Ca) and phosphorus (P) (F-CaP: Ca 87 mg/dl, P 43 mg/dl) and compared to the non-supplemented form (F: Ca 62 mg/dl, P 36 mg/dl). VLBW and small-for-gestational-age infants (n = 79) were included in the study which was performed to look for adverse effects and to decide about a reasonable start and duration of supplementation. In preterm infants with a birth weight lower than 1500 g and a body weight of more than 2000 g, the additional supplementation with Ca and P lead to a significant higher Ca- and P-retention without further load for the kidney. In addition, preterm infants with a body weight lower than 1500 g also had a better retention of Ca and P. Both, F-CaP and F lead to a high urinary excretion of phosphorus, a high renal net acid excretion and a relatively high activity of serum alkaline phosphatase. Anthropometric measurements did not reveal any evidence for an impaired caloric absorption due to an increased fecal fat excretion. Hypercalcemia or hyperphosphatermia was not seen. Hypercalciuria occurred in less than 5% of the samples studied. The results of this study indicate that a continuation of the supplementation with Ca and P is justified in VLBW infants with a body weight of more than 2000 g. There was no evidence for adverse effects of Ca and P supplementation in VLBW infants with a body weight lower than 1500 g, who might therefore also benefit from supplementation. Further studies are necessary to investigate unsatisfactory metabolic conditions of these children e.g. the high renal load.

Urinary excretion of aldosterone, arginine vasopressin and cortisol in premature infants with maximum renal acid stimulation

Of 452 low-birth-weight infants who were routinely screened for maximum renal acid stimulation (MRAS) (urine pH < 5.4), 149 episodes of incipient late metabolic acidosis (urine pH < 5.4 on 2 consecutive days) were randomly allocated to either a control group or treatment with NaHCO3 or NaCl (2 mmol/kg/day each) for 7 days. Urinary excretion of aldosterone-18-glucuronide (Aldo), arginine vasopressin (AVP) and cortisol was determined in timed urine samples. On day 1, patients with MRAS showed a tendency towards increased urinary excretion of Aldo compared with infants without MRAS. In patients who received alkali therapy, urinary excretion of Aldo, AVP and cortisol decreased or showed a trend to lower values from day 1 to day 7, whereas in patients with MRAS but no specific therapy, Aldo and AVP showed a tendency to increase. We concluded that persistent MRAS is not only characterized by a reduced rate of weight gain and a tendency to decreased nitrogen assimilation, but also increased secretion of Aldo and AVP.

Presence of re-appearance of BCR-ABL-positive cells years after allogeneic bone marrow transplantation for chronic-phase chronic myelogenous leukemia in patients in hematological remission

Allogeneic bone marrow transplantation (BMT) is considered to be the only curative therapy for chronic myelogenous leukemia (CML). The cytogenetic marker of CML, the Philadelphia (Ph) chromosome, or the molecular alterations caused by the BCR-ABL gene fusion can be used to monitor the success of treatment. A sensitive two-step reverse-transcription polymerase chain reaction (RT-PCR) was done to score BCR-ABL-mRNA-positive leukemic cells in frozen bone marrow samples of 15 CML patients retrospectively. These patients, 4 females, 11 males, had undergone BMT during the first chronic phase after a preparative regimen consisting of total body irradiation (TBI) and cyclophosphamide; median age at BMT was 38 years (range 20-49 years). At the time of this study, 8 patients were in cytogenetic and/or clinical remission. Seven patients relapsed after BMT; all presented with Ph-chromosome-positive metaphases and BCR-ABL-positive cells at the time of relapse. In only 1 patient in hematologic remission was no positive PCR analysis obtained in the two samples tested. However, 5 patients have remained or became Ph-chromosome and/or PCR-positive after BMT without clinical symptoms of disease. In samples from another patient, transient presence of leukemic cells was observed only early after BMT. Clinically, these patients were relapse free at days 3,055, 2,581, 2,252, 1,846, 1,839, 1,747, and 1,173 after BMT, respectively. Based on these data, the presence of single BCR-ABL-positive cells > 1 year after BMT has no prognostic significance.

Increased renal net acid excretion in prematures below 1,600 g body weight compared with prematures and small-for-date newborns above 2,100 g on alimentation with a commercial preterm formula

In 76 low birth weight infants with an actual body weight ranging from 1,210 to 2,540 g and fed a commercial preterm formula, urine samples were collected and blood acid base status was measured on day 38 (+/- 17, mean +/- SD) of life. Infants with an actual body weight below 1,600 g demonstrated a higher daily weight gain (22 +/- 3 vs. 14 +/- 5 g/kg/day), lower blood pCO2 (35.4 +/- 5.0 vs. 38.9 +/- 3.8 mm Hg), lower urine pH (5.8 +/- 0.5 vs. 6.5 +/- 0.3), higher renal net acid (1.86 +/- 0.38 vs. 1.28 +/- 0.55 mmol/kg/day) and higher phosphorus excretion (0.67 vs. 0.52 mmol/kg/day) than infants with an actual body weight above 2,100 g. Urinary ionogram data of these 2 groups of infants show that the increased renal net acid excretion of the smaller prematures is the result of a lower urinary excretion of sodium, potassium and chloride, due to a higher daily weight gain, probably a higher retention of these minerals, and a higher urinary phosphorus excretion probably due to an age-specific lower intestinal calcium absorption, and therefore a lower rate of calcium and phosphorus retention. Considering the low renal capacity for hydrogen ion excretion, very low birth weight infants still run a considerable risk for disturbances of acid base metabolism due to the high mean level of net acid excretion in nutrition with preterm formulas and an additional age-specific augmentation of renal acid load.

The Haldane effect under different acid-base conditions in premature and adult humans

The Haldane effect (HE) was investigated in human adults and prematures under normal metabolic acid-base conditions but at different levels of PCO2. Venous blood samples were equilibrated with low and high PCO2 in either O2 or N2. The change in plasma pH of oxygenated blood by deoxygenation did not differ between both groups. Thus, ontogenetic differences of human hemoglobin structure do not influence the net proton Haldane effect measured in terms of whole blood pH-changes. Since the present data quantitatively agree with those we reported earlier for rabbits, cats and dogs (Kiwull-Schöne et al., 1992), phylogenetic differences in hemoglobin structure of these mammalian species do not either seem to play a role in this respect. The influence of the Haldane effect on plasma pH has to be considered in blood-gas and acid-base analysis of samples with incomplete oxygenation. This is important for the indirect determination of PCO2 through pH by the equilibration method (Astrup and Schrøder, 1956), serving as reference method for determination of metabolic acid-base status and CO2 buffering capacity. Likewise, HE-correction is important for indirect estimation of metabolic acid-base status (BE and HCO-3st) from clinical routine PCO2- and pH-measurement. In spite of the vaste amount of literature on the Haldane effect in human blood, quantitative data for practical purpose are less available and still equivocal. By the present study, a strong inverse linear correlation between the HE-induced delta pH and 1g[HCO3-] could be shown over a wide range of acid-base changes.(ABSTRACT TRUNCATED AT 250 WORDS)

Decreased growth rate of low-birth-weight infants with prolonged maximum renal acid stimulation

In a prospective randomized study, the urine pH of 170 premature and small-for-gestational-age (SGA) newborns was routinely screened to detect patients with spontaneously developing maximum renal acid stimulation, an obligatory early stage in the development of late metabolic acidosis. Nitrogen assimilation was evaluated from the ratio of urinary nitrogen excretion and intake. Forty-two premature infants and 10 SGA prematures and newborns after intensive care therapy with body weights greater than 1.5 kg and 25 prematures (including 7 SGA infants) with body weights less than 1.5 kg, spontaneously showed urine pH values below 5.4 on two consecutive days, suggesting maximum renal acid stimulation. These patients were randomly given either oral alkali therapy with sodium bicarbonate 2 mmol/kg/day or no therapy for a period of seven days. In both groups, urine pH was controlled daily. Patients in the control group without alkali therapy and with urine pH values less than 5.4 for seven days showed a significant decrease in weight gain and a tendency to decreased nitrogen assimilation. We assume that a regular check of urine pH in low-birth-weight infants is a useful non-invasive method of detecting patients in the early stages of development of late metabolic acidosis, i.e. in the stage of "incipient late metabolic acidosis". This would provide the possibility of starting early effective therapy and thereby reduce the mean duration of admission to neonatal wards.(ABSTRACT TRUNCATED AT 250 WORDS)

Low renal net acid excretion, high calciuria and biochemical signs of sodium deficiency in low-birth-weight infants fed a new low-phosphorus formula

In 11 infants (birth weight greater than 1800 g) fed a new type of humanized formula with a low phosphorus (P) content (calcium (Ca) 11 mmol/l, P 7.2 mmol/l, sodium (Na) 8.3 mmol/l) biochemical parameters of blood, serum and urine were determined. In nine boys Ca and P balances were evaluated also. Renal net acid excretion was low (0.85 mmol/kg/day). Mean concentrations of P and Ca in urine were 0.34 mmol/kg/day (10.5 mg/kg/day) and 0.1 mmol/kg/day (4 mg/kg/day), respectively. In four infants, Ca concentration in urine was, however, greater than 0.15 mmol/kg/day) (6 mg/kg/day). In infants with birth weights greater than 1800 g fed the new, low-P formula, the low renal net acid excretion, the normal P and the high Ca concentrations in urine were comparable to term infants fed human milk. The high calciuria in several infants may be normal physiologic values. However, it remains to be established that the urinary solubility product of infants fed the new, low-P formula is in the same range as those for infants fed human milk. Unexpectedly, low urinary Na excretion (0.26 mmol/kg/day) and increased urinary excretion of aldosterone-18-glucuronide indicated biochemical evidence of Na deficiency secondary to low Na intake and a high weight gain. If the new, low-P formula is to be fed to infants with a birth weight as low as 1800 g. Na content should be higher than in mature human milk because of the often relatively higher weight gain.

Multiple minute marker chromosomes derived from Y identified by FISH in an intersexual infant

Chromosomal analysis in a child with ambiguous sex showed mosaicism of at least two cell lines with one or more marker chromosomes or none at all. They were shown to be derived from the Y chromosome by fluorescent in situ hybridisation (FISH) using different DNA probes that cover parts of the long and the short arm.

Effect on renal net acid excretion of various mineral contents in three lots of a common pre-term formula

Three common lots (A, B, C) of a common formula for pre-term infants, which contained unintended, high differences in mineral contents were fed consecutively in a neonatal unit. In each feeding period parameters of calcium-phosphorus and acid-base metabolism were determined prospectively. Infants fed lot C showed unexpectedly high renal net acid excretion. In order to discover the origin of this different renal net acid excretion, the urinary concentration of further electrolytes, sulfate, urea and organic acids were determined retrospectively in three randomly selected groups with 10 pre-term infants each. Infants fed lot C showed a higher renal net acid excretion (2.97 mmol/kg per day) than infants fed lot A (1.75 mmol/kg per day) or lot B (1.72 mmol/kg per day). Based on the data of mineral and nitrogen intake and the urinary values of all main ions and urea it is assumed that the increased renal acid load in infants fed lot C is due to the additive effect of different mineral concentrations resulting in a low "alkali excess" (Na + K - Cl) of lot C and a decreased protein assimilation. The production of infant formulas for prematures should be more closely monitored to avoid marked deviation of the mineral contents in individual lots from the concentrations shown on the label.

Suboptimal mineral composition of cow's milk formulas: a risk factor for the development of late metabolic acidosis

Late metabolic acidosis was observed in a term baby boy with renal tubular acidosis type 4 who received two cow's milk formulas in succession. Suboptimal mineral composition of the formulas turned out to be an important risk factor for the development of late metabolic acidosis.

Effect of calcium supplementation on calcium and phosphorus balance and renal net acid excretion in preterm infants fed a standard formula

In 19 preterm infants fed a standard formula for prematures (calcium (Ca) 13.5 mmol/l; phosphorus (P) 12.9 mmol/l), biochemical parameters of blood, serum and urine were determined before and during supplementation with Ca-L-lactate (final Ca concentration 20 mmol/l). In 8 preterm boys Ca and P balance were evaluated in addition. During Ca supplementation, the serum Ca levels, urine pH (without supplement 6.31, with supplement 6.73), and calciuria (46 mumol/kg/d vs. 98 mumol/kg/d) were increased, and urinary P (1.05 mmol/kg/d vs. 0.65 mmol/kg/d) and net acid excretion (1.70 mEq/kg/d vs. 0.89 mEq/kg/d) were decreased. Balance studies showed increased net intestinal Ca absorption during supplementation (37% vs. 56%) as well as improved Ca (0.8 mmol/kg/d vs. 1.85 mmol/kg/d) and P retention (0.97 mmol/kg/d vs. 1.45 mmol/kg/d). These data show that increased Ca intake given to optimize the Ca:P ratio improves mineral retention in preterm infants fed a standard formula. Ca and P intake should be thoroughly balanced to avoid side-effects like hypercalciuria or high renal net acid excretion.

[Continuous ambulatory peritoneal dialysis (CAPD) in children and adolescents]

Continuous ambulatory peritoneal dialysis (CAPD) is a relatively new blood purification method applicable as an alternative to intermittent hemodialysis in the treatment of end-stage renal disease. In this report we discussed the results of more than five years of CAPD in 32 children and adolescents aged 0.1 to 18 years treated for up to 22 months as well as the advantages and disadvantages of this technique in comparison to hemodialysis. Technical survival after one year of treatment increased from 48% in patients treated before 1983 to 84% in patients treated thereafter. Simplicity of technical procedure and lack of pain are considered the major advantages. Thus home dialysis can be performed even under adverse conditions (e.g. in infants). Infections of the abdominal cavity and the catheter tunnel are severe complications of CAPD. In the course of the last two years the frequency of peritonitis dropped to one episode per treatment year. We want to stress that successful treatment can be achieved by adequately training patients and their parents to perform home dialysis on their own and by surveying patients regularly according to standardized treatment guidelines in a pediatric nephrology unit.

[Collection and bacteriologic quick testing of the milk of mothers with premature infants]

Collecting milk from mothers of preterm infants and feeding it unprocessed to their own babies has been tested. Mothers were instructed by protocoll and by intensive personal informations. Unprocessed human milk samples were bacteriologically screened by Uricult-dip-slides. 69% of 2,261 milk samples examined showed a total colony count of less than or equal to 10(4)/ml and no growth of gramnegative bacteria. These samples could be given unprocessed to the preterm infants. No side effects have been noticed. Bacteriological criteria for feeding unprocessed human milk are discussed in the paper.

[van Bogaert-Bertrand spongy cerebral dystrophy]

We report on a male infant with spongy degeneration of the central nervous system (van Bogaert and Bertrand type), who died at the age of 7 months. The clinic as well as the diagnostic procedure are described, especially the importance of cranial computerized tomography for the diagnosis.

Psychosocial adaptation of children and their parents to hospital and home hemodialysis

Psychosocial adaptation of 20 children and adolescents treated by regular hemodialysis and their parents was analyzed by detailed semistructured interviews and questionnaires. The results in 10 patients treated in the centre and 10 followed at home were compared. The burdens of patients and parents induced by therapy as well as compliance, educational aspects and school activity in the treated children are described. Home dialysis usually provoked more fears of complications and aggressive feelings in patients and stress in parents but was superior to centre treated patients regarding social contacts and school activity of patients. From the data obtained, a comprehensive programme of psychosocial care for children with end-stage kidney disease was derived, including detailed instruction for parents and teachers of children on regular dialysis treatment.

[Kidney transplantation in childhood]

40 renal transplantations on children up to 15 years of age have been performed in our hospital in the years 1976 to June 1982 with one exception in 1972. We did verify the findings of previous authors that renal transplantation in children has produced good results so far (1, 5, 6). Dialysis treatment in children often evokes extreme problems for the patients, parents, and medical team. Considering this dialysis is seen as only a provisional measure, transplantation however as the final aim in the therapeutic concept of children with terminal renal insufficiency (1). Furthermore dialysis treatment for infants is justified in our opinion only if a renal transplantation ca be realized.

[Mezlocillin concentrations in the serum of children with impaired renal function]

Mezlocillin was administered as an intravenous bolus injection to eight children, aged 4-15, requiring antibiotic therapy; the dose was either 75 mg/kg or 37.5 mg/kg. All of the patients had advanced renal insufficiency. Five of the children required chronic intermittent hemodialysis. The microbiological method of Grove and Randall was used for the quantitative determination of mezlocillin in the serum. Ten minutes after the injection, the concentration of mezlocillin in the serum was approximately 90 mg/l and 40 mg/l, respectively. The determinations 30 and 60 minutes after the injection showed that the mezlocillin concentrations had fallen rapidly to approximately 30 mg/l and 20 mg/l, respectively. The mezlocillin concentrations were still approximately 2 mg/l and 1 mg/l, respectively, 12 hours after administration. For the period between 10 and 60 minutes, the half-lives were between 33 and 57 minutes. In general, we can conclude that a single bolus injection of 75 mg/kg will result in mezlocillin concentrations in the serum of uremic children which allow us to expect good antibacterial efficacy, at least for the first few hours following the injection. On the basis of our studies, half the dosage does not appear to be sufficient.

[Successful treatment of renal hypertension in a 2 1/2-year-old girl with the converting enzyme inhibitor captopril (author's transl)]

A girl aged 2 1/2 year on chronic hemodialysis, treated with converting enzyme inhibitor Captopril because of severe uncontrollable renal hypertension, returned for the first time to a satisfactory stable blood pressure. After three months of this therapy the bilateral nephrectomy was performed. Two weeks later the patient showed a stable blood pressure, normal for age. None of the known side effects was seen. Whether the oxalat deposits found with nephrectomy were due to the treatment with Captopril, cannot yet be answered.

[Pattern of serum and red cell electrolytes in acute haemolytic uraemic syndrome (author's transl)]

Sodium, potassium and magnesium were measured in serum resp. plasma and in erythrocytes of oliguricanuric children with acute haemolytic uraemic syndrome (HUS). Potassium was in serum resp. plasma and in red cells in normal range or decrease compared with other forms of acute renal failure in children. These findings were different to statements in the relevant literature, which describe hyperkaliaemia. We suppose a potassium depletion in the early state of HUS. The cause is still unknown. Furthermore we found a hyponatriaemia according to severity of edema and gastroenteritis. Sodium in red cells and magnesium in plasma and erythrocytes were slightly elevated.

[Treatment of the hemolytic-uremic syndrome with streptokinase and heparin (author's transl)]

In a clinical study we treated 16 children, suffering from severe hemolytic-uremic syndrome (HUS), with streptokinase or heparin. All children received the same symptomatic treatment (early dialysis, transfusion of packed red cells). A control group of 10 children was only treated symptomatically. No difference could be shown in clinical grading of severity. We analysed the results of the acute phase and of a follow up study of 1-5 years, which is not yet complete. The results show, that heparin could not improve the prognosis of HUS in comparison to streptokinase or symptomatic treatment. The results of streptokinase treatment were not better than in the control group. In 4 children we saw severe bleeding complications of streptokinase therapy. Accepting the complication rate of a drug and the incidence of chronic renal disease as criterium of the efficacy of drug treatment in severe HUS, streptokinase and heparin are not indicated. We believe, that patients should be managed symptomatically with early dialysis.

[Eye manifestations of subacute sclerosing panencephalitis]

A report is given on 10 children with subacute sclerosing panencephalitis (SSPE) whose clinical illness began with visual or mental impairment. All patients showed typical clinical and neurologic features and various ophthalmological manifestations. The latter correspond to lesions generally dealt with in a number of reports and demonstrate for the individual case that ophthalmological manifestation can precede clinical manifestation. The ophthalmologist can give an important contribution to the diagnosis. In some cases the focal retinal lesions can be similar to retinal lesions in the case of toxoplasmosis. A positive antibody titer for toxoplasmosis, which can occur parallel with the typical measles or SSPE virus antibody titer, occasionally causes the misdiagnosis of toxoplasmosis acquisita. In the 10 cases reported on, the diagnosis SSPE was confirmed on the basis of the typical clinical features and elevated measles virus antibody titer. In no case the permission for autopsy was gained. The genesis of SSPE is discussed with reference to a genetic defect, to an autoimmune reaction, or as a result of a measles virus-like infection. In the diagnosis, primarily unclear 'focal retinal lesions' should be at any rate investigated with respect to measles or SSPE virus antibody titer.

[Sodium, potassium and magnesium in plasma and erythrocytes during haemodialysis of children (author's transl)]

In 19 children with chronic renal insufficiency sodium, potassium and magnesium in plasma and erythrocytes were measured before and after haemodialysis. Creatinine and the acid-base status were also determined. The mean predialysis values of sodium in plasma were within normal limits, in erythrocytes in the lower normal range. Potassium was elevated in plasma, and in erythrocytes within the normal linits. Magnesium was elevated in both plasma and erythrocytes. The changes during dialysis are described. Statistically significant relations of investigated variables are also described. The results are discussed.

[Familial nephropathy with retinitis pigmentosa and peripheral dysostosis]

The paper reports two siblings, 6 and 3 3/4 years old, with a congenital nephropathy (nephronophthisis), retinitis pigmentosa, heart failure and peripheral dysostosis. The severe histological changes of the kidneys with tubular atrophy and interstitial fibrosis caused the death of the older sister at the age of 7 years. The symptoms of our patients are discussed in comparison to the syndrome described by MAINZER et al.

[Cerebrospinal fluid rhinorrhea in achondroplasia with hydrocephalus (author's transl)]

Cerebrospinal fluid rhinorrhea was observed in a 12-year old girl with achondroplasia and communicating hydrocephalus. The leakage ceased and did not recur after treatment by ventriculo-atrial shunting (Holter valve) without plugging the fistula. The pathogenetic factors in this case are discussed.