Central nervous system manifestations of LRBA deficiency: case report of two siblings and literature review

BACKGROUND

LPS-responsive beige-like anchor protein (LRBA) deficiency is a primary immunodeficiency disease (PID) characterized by a regulatory T cell defect resulting in immune dysregulation and autoimmunity. We present two siblings born to consanguineous parents of North African descent with LRBA deficiency and central nervous system (CNS) manifestations. As no concise overview of these manifestations is available in literature, we compared our patient's presentation with a reviewed synthesis of the available literature.

CASE PRESENTATIONS

The younger brother presented with enteropathy at age 1.5 years, and subsequently developed Evans syndrome and diabetes mellitus. These autoimmune manifestations led to the genetic diagnosis of LRBA deficiency through whole exome sequencing with PID gene panel. At 11 years old, he had two tonic-clonic seizures. Brain MRI showed multiple FLAIR-hyperintense lesions and a T2-hyperintense lesion of the cervical medulla.  His sister presented with immune cytopenia at age 9 years, and developed diffuse lymphadenopathy and interstitial lung disease. Genetic testing confirmed the same mutation as her brother. At age 13 years, a brain MRI showed multiple T2-FLAIR-hyperintense lesions. She received an allogeneic hematopoietic stem cell transplantation (allo-HSCT) 3 months later. Follow-up MRI showed regression of these lesions.

CONCLUSIONS

Neurological disease is documented in up to 25% of patients with LRBA deficiency. Manifestations range from cerebral granulomas to acute disseminating encephalomyelitis, but detailed descriptions of neurological and imaging phenotypes are lacking. LRBA deficiency amongst other PIDs should be part of the differential diagnosis in patients with inflammatory brain lesions. We strongly advocate for a more detailed description of CNS manifestations in patients with LRBA deficiency, when possible with MR imaging. This will aid clinical decision concerning both anti-infectious and anti-inflammatory therapy and in considering the indication for allo-HSCT.

Disseminated Tuberculosis Mimicking as Crohn's Disease in a Paediatric Patient

Tuberculosis is an important infectious disease for children worldwide. The clinical presentation of tuberculosis in children is diverse and, depending on the affected organs, it is often accompanied with nonspecific symptoms that can mimic other diseases. In this report, we present a case of disseminated tuberculosis in an 11-year-old boy with intestinal followed by pulmonary involvement. The diagnosis was delayed for several weeks due to the clinical picture which was mimicking Crohn's disease, the known difficulties in diagnostic tests and the improvement on meropenem. This case demonstrates the importance of a detailed microscopic examination of gastrointestinal biopsies and the tuberculostatic effect of meropenem which physicians should be aware of.

Aberrant Mucin Expression Profiles Associate With Pediatric Inflammatory Bowel Disease Presentation and Activity

BACKGROUND

Intestinal mucosal healing is nowadays preferred as the therapeutic endpoint in inflammatory bowel disease (IBD), but objective measurements at the molecular level are lacking. Because dysregulated mucin expression is suggested to be involved in mucosal barrier dysfunction in IBD, we investigated mucin expression in association with barrier mediators and clinical characteristics in colonic tissue of a pediatric IBD population.

METHODS

In this cross-sectional monocentric study, we quantified messenger RNA (mRNA) expression of mucins, intercellular junctions, and cell polarity complexes in inflamed and noninflamed colonic biopsies from pediatric IBD (n = 29) and non-IBD (n = 15) patients. We then validated mucin expression at protein level and correlated mucin mRNA expression with expression of barrier mediators and clinical data.

RESULTS

The expression of MUC1, MUC3A, MUC4, and MUC13 was increased in the inflamed colon of pediatric IBD patients compared with the noninflamed colon of non-IBD control subjects. Especially MUC13 mRNA expression associated with the expression of barrier mediators, including CDH1, OCLN, and TJP2. MUC1 and MUC3B mRNA expression in combination with calprotectin levels most accurately discriminated IBD patients from non-IBD control subjects (90.6% area under the receiver-operating characteristic curve [AUCROC], 92.0% sensitivity, 73.7% specificity), whereas aberrant mRNA expression of MUC1, MUC3A, MUC4, and MUC13 was distinctive for ulcerative colitis and of MUC3B for Crohn's disease. Furthermore, expression of MUC3A, MUC3B, and MUC4 correlated with clinical disease activity (ie, Pediatric Ulcerative Colitis Activity Index and Pediatric Crohn's Disease Activity Index), and of MUC1, MUC2, MUC4, and MUC13 with endoscopic colitis severity in ulcerative colitis patients.

CONCLUSIONS

Colonic mucin expression is disturbed in pediatric IBD patients and associates with disease activity and presentation, suggesting its use as molecular marker to aid in disease diagnosis and management.

Long-term outcome of LRBA deficiency in 76 patients after various treatment modalities as evaluated by the immune deficiency and dysregulation activity (IDDA) score

BACKGROUND

Recent findings strongly support hematopoietic stem cell transplantation (HSCT) in patients with severe presentation of LPS-responsive beige-like anchor protein (LRBA) deficiency, but long-term follow-up and survival data beyond previous patient reports or meta-reviews are scarce for those patients who do not receive a transplant.

OBJECTIVE

This international retrospective study was conducted to elucidate the longitudinal clinical course of patients with LRBA deficiency who do and do not receive a transplant.

METHOD

We assessed disease burden and treatment responses with a specially developed immune deficiency and dysregulation activity score, reflecting the sum and severity of organ involvement and infections, days of hospitalization, supportive care requirements, and performance indices.

RESULTS

Of 76 patients with LRBA deficiency from 29 centers (median follow-up, 10 years; range, 1-52), 24 underwent HSCT from 2005 to 2019. The overall survival rate after HSCT (median follow-up, 20 months) was 70.8% (17 of 24 patients); all deaths were due to nonspecific, early, transplant-related mortality. Currently, 82.7% of patients who did not receive a transplant (43 of 52; age range, 3-69 years) are alive. Of 17 HSCT survivors, 7 are in complete remission and 5 are in good partial remission without treatment (together, 12 of 17 [70.6%]). In contrast, only 5 of 43 patients who did not receive a transplant (11.6%) are without immunosuppression. Immune deficiency and dysregulation activity scores were significantly lower in patients who survived HSCT than in those receiving conventional treatment (P = .005) or in patients who received abatacept or sirolimus as compared with other therapies, and in patients with residual LRBA expression. Higher disease burden, longer duration before HSCT, and lung involvement were associated with poor outcome.

CONCLUSION

The lifelong disease activity, implying a need for immunosuppression and risk of malignancy, must be weighed against the risks of HSCT.

Evaluation of a European-wide survey on paediatric endoscopy training

OBJECTIVE

To evaluate quality of paediatric endoscopy training of Young members of the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN).

METHODS

An online questionnaire designed by the Young ESPGHAN Committee was sent to 125 Young ESPGHAN members between February 2014 and September 2015. The questionnaire comprised 32 questions addressing some general information of the participants and the structure of their paediatric gastroenterology, hepatology and nutrition programmes; procedural volume and terminal ileal intubation (TII) rate; supervision, assessments, participation in endoscopy courses and simulator training; and satisfaction with endoscopy training and self-perceived competency.

RESULTS

Of 68 participants, 48 (71%) were enrolled in an official training programme. All alumni (n=31) were trained in endoscopy. They completed a median of 200 oesophagogastroduodenoscopies (OGDs) and 75 ileocolonoscopies (ICs) with a TII rate of >90% in 43%. There is a significant difference in numbers of ICs between the TII rate groups >90%, 50%-90% and <50% (median 150 vs 38 vs 55) (p<0.001). 11 alumni (35%) followed the ESPGHAN Syllabus during training. 25 alumni (81%) attended basic skills endoscopy courses and 19 (61%) experienced simulator training. 71% of the alumni were '(very) satisfied' with their diagnostic OGD, while 52% were '(very) satisfied' with their IC training. The alumni felt safe to independently perform OGDs in 84% and ICs in 71% after their training.

CONCLUSIONS

Despite reaching the suggested procedural endoscopy volumes, a rather low TII rate of >90% calls for end-of-training certifications based on the achievement of milestones of competency.

Hepatitis B virus vaccination and revaccination response in children diagnosed with coeliac disease : a multicentre prospective study

AIM

This study evaluates hepatitis B virus (HBV) vaccination response in children with celiac disease (CD). Response in initial non-responders after a single booster vaccination as well as factors influencing HBV vaccination response were evaluated.

METHODOLOGY

Anti-hepatitis B surface antibodies (a-HBsAB) were checked in all children with CD and a documented complete HBV vaccination. An a-HBsAB <10 U/L was considered as non-response. A single intramuscular HBV-vaccine booster was advised to all non-responders. Response was checked at the next appointment.

RESULTS

133 children with CD were included, median age of 7.3 years (range 1.7-17.3) and 46 (35%) were male. The age at CD diagnosis was 6.0 years (range 1.1-15.7). HBV non-response was documented in 55% (n=73/133). No other factors were influencing the response. A booster was documented in 34/73 (47 %) initial non-responders (3 refused (4%), 36 (49%) had no follow up). Response after booster vaccination resulted in immunity in 22/34 (65%) and persisting non-response in 12/34 (35%). A single booster is able to reduce non-response from 55% (73/133) to 23% (22/94).

CONCLUSION

A significantly lower immune response following HBV vaccination in children with CD was confirmed. A single intramuscular booster vaccination is able to induce a serologic response in two thirds of the initial non-responders. Control of HBV vaccination response has to become part of the follow-up in CD patients.

A novel human STAT3 mutation presents with autoimmunity involving Th17 hyperactivation

Mutations in STAT3 have recently been shown to cause autoimmune diseases through increased lymphoproliferation. We describe a novel Pro471Arg STAT3 mutation in a patient with multiple autoimmune diseases, causing hyperactivation of the Th17 pathway. We show that IL-17 production by primary T cells was enhanced and could not be further increased by IL-6, while IL-10 reduced Th17 cell numbers. Moreover, specific inhibition of STAT3 activation resulted in diminished IL-17 production. We show that the Pro471Arg STAT3 mutation yields both increased levels of IgA and IgG, probably due to high IL-21 levels. When remission was reached through medical intervention, IL-17 levels normalized and the clinical symptoms improved, supporting the idea that STAT3 gain-of-function mutations can cause hyperactivation of the Th17 pathway and thereby contribute to autoimmunity.

Safety and efficacy of femoral artery closure with the FemoSeal® device after coronary angiography using a 7 French sheath

Post-cardiac catheterization femoral artery hemostasis can be accomplished with several mechanisms, including the FemoSeal® hemostasis device which has been designed and approved for closure of 6 French (F) arterial puncture sites. The aim of this study was to investigate whether the FemoSeal® vascular closure device can effectively and safely seal 7F arterial puncture sites after diagnostic and interventional cardiac catheterizations.

Femoral artery puncture sites of 50 consecutive patients undergoing cardiac catheterization were closed with the FemoSeal® vascular closure device, according to the manufacturer’s instructions. Efficacy endpoints were time to hemostasis and successful ambulation. Safety endpoints included bleeding complications, vessel occlusion and pseudoaneurysms.

Mean time to hemostasis was 57.8±26.3 seconds (0-125 seconds). Hemostasis was achieved in 100 percent of the 50 patients. One patient suffered minor bleeding the next day, i.e. local hematoma.

This clinical study demonstrates that the FemoSeal® vascular closure device, initially approved for closure of 6F arterial puncture sites, shows promising efficacy and safety to seal a larger (7F) femoral arterial puncture sites after diagnostic and interventional cardiac catheterizations.

Reduced expression of FOXP3 and regulatory T-cell function in severe forms of early-onset autoimmune enteropathy

BACKGROUND & AIMS

Little is known about the pathophysiology of early onset forms of autoimmune enteropathy (AIE). AIE has been associated with mutations in FOXP3-a transcription factor that controls regulatory T-cell development and function. We analyzed the molecular basis of neonatal or early postnatal AIE using clinical, genetic, and functional immunological studies.

METHODS

Gastroenterological and immunological features were analyzed in 9 boys and 2 girls with AIE that began within the first 5 months of life. FOXP3 and IL2RA were genotyped in peripheral blood monocytes. FOXP3 messenger RNA and protein expression were analyzed using reverse-transcription polymerase chain reaction, flow cytometry, and confocal immunofluorescence of CD4(+) T cells. Regulatory T-cell function (CD4(+)CD25(+)) was assayed in coculture systems.

RESULTS

AIE associated with extraintestinal autoimmunity was severe and life-threatening; all patients required total parenteral nutrition. Regulatory T cells from 7 patients had altered function and FOXP3 mutations that resulted in lost or reduced FOXP3 protein expression; 2 infants had reduced regulatory T-cell activity and reduced levels of FOXP3 protein, although we did not detect mutations in FOXP3 coding region, poly-A site, or promoter region (called FOXP3-dependent AIE). Two patients had a normal number of regulatory T cells that expressed normal levels of FOXP3 protein and normal regulatory activity in in vitro coculture assays (called FOXP3-independent AIE). No mutations in IL2RA were found.

CONCLUSIONS

Most cases of AIE are associated with alterations in regulatory T-cell function; some, but not all, cases have mutations that affect FOXP3 expression levels. Further studies are needed to identify mechanisms of AIE pathogenesis.

IL-15 renders conventional lymphocytes resistant to suppressive functions of regulatory T cells through activation of the phosphatidylinositol 3-kinase pathway

IL-15 drives chronic inflammation in several human diseases. We have recently shown that IL-15 inhibits the immunosuppressive effects of TGF-beta through blockage of the Smad3-signaling pathway. Data pointing to reciprocal interactions between TGF-beta and CD4(+) regulatory T cells led us to investigate the impact of IL-15 on the de novo generation and function of regulatory T cells in humans. Our data indicate that IL-15 does not counteract, but rather promotes the effect of TGF-beta on the de novo generation of regulatory T cells (Treg). Thus, in the presence of TGF-beta, IL-15 enhanced the acquisition of regulatory functions by CD4(+)CD25(-) T cells stimulated by anti-CD3 and anti-CD28 Abs. In contrast, IL-15 impaired the functions of Tregs by acting on effector CD4 and CD8 T cells. Accordingly, in the presence of IL-15, proliferation and IFN-gamma production by peripheral CD4 and CD8 T cells could not be efficiently inhibited by Tregs. IL-15-induced resistance of effector T cells to Tregs resulted from activation of the PI3K signaling pathway but did not involve the rescue of effector T cells from apoptosis. Altogether, these data point to the ambiguous role of IL-15 in the control of Treg functions. This dual role may be instrumental to mount rapid but transient proinflammatory immune responses against pathogens but may become deleterious in situations associated with protracted IL-15 over-expression.

Severe food allergy as a variant of IPEX syndrome caused by a deletion in a noncoding region of the FOXP3 gene

BACKGROUND & AIMS

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX; OMIM 304930) syndrome is a congenital syndrome characterized by autoimmune enteropathy, endocrinopathy, dermatitis, and other autoimmune phenomena. In the present work, we aimed to uncover the molecular basis of a distinct form of IPEX syndrome presenting at the edge of autoimmunity and severe allergy.

METHODS

The FOXP3 gene was sequenced, FOXP3 messenger RNA (mRNA) was quantified by real-time polymerase chain reaction (PCR), and protein expression in peripheral blood lymphocytes was analyzed by flow cytometry after intracellular staining. In coculture experiments (CD4(+)CD25(-) and CD4(+)CD25(+) cells), the functions of regulatory T cells were analyzed. Expression of interferon gamma and interleukin 2 and 4 mRNA within the inflamed intestinal mucosa was quantified by real-time PCR.

RESULTS

Here, we describe a distinct familial form of IPEX syndrome that combines autoimmune and allergic manifestations including severe enteropathy, food allergies, atopic dermatitis, hyper-IgE, and eosinophilia. We have identified a 1388-base pair deletion (g.del-6247_-4859) of the FOXP3 gene encompassing a portion of an upstream noncoding exon (exon -1) and the adjacent intron (intron -1). This deletion impairs mRNA splicing, resulting in accumulation of unspliced pre-mRNA and alternatively spliced mRNA. This causes low FOXP3 mRNA levels and markedly decreased protein expression in peripheral blood lymphocytes of affected patients. Numbers of CD4(+)CD25(+)FOXP3(+) regulatory T cells are extremely low, and the CD4(+)CD25(+) T cells that are present exhibit little regulatory function.

CONCLUSIONS

A new mutation within an upstream noncoding region of FOXP3 results in a variant of IPEX syndrome associating autoimmune and severe immunoallergic symptoms.

Severe dysimmune cytopenia in children treated with tacrolimus after organ transplantation

Rare cases of dysimmune phenomena after solid organ transplantation were described in the past. In the present series, we describe six children who developed severe dysimmune anemia or thrombocytopenia while treated with tacrolimus after liver or small bowel transplantation. All patients were off steroids or under low doses alternate day steroid medication when dysimmune cytopenia developed. All patients had positive anti-platelets antibodies and/or Coombs' positive anemia. Therapy was successful in all six patients with a rapid response to corticosteroids in three children, and to anti-CD20 monoclonal antibodies (rituximab) in the three others. The pathogenesis of these rare dysimmune/autoimmune disorders might be related to the interference of tacrolimus with T-cell functions and/or the endogenous control mechanisms of T-lymphocyte activation and down-regulation. Although rare, these complications must be known when discussing protocols of immunosuppression.

Single coronary artery bypass grafting--a comparison between minimally invasive 'off pump' techniques and conventional procedures

OBJECTIVE

At present, few studies directly comparing minimally invasive and conventional coronary artery bypass grafting are available. The aim of the present study was to evaluate the clinical outcome of the two techniques.

METHODS

We retrospectively compared our first consecutive 20 patients undergoing minimally invasive coronary artery single bypass grafting on the beating heart (group I) with 23 consecutive patients receiving single coronary artery bypass via sternotomy using cardiopulmonary bypass and cardioplegia (group II). The procedures were performed during the period from Jan 1, 1994 to Feb 20, 1997. There were no significant differences in demographic data.

RESULTS

Statistically significant differences were found concerning total operative time (172.6 min in group I and 149.6 min in group II P = 0.0009) and myocardial ischemic time (23.7 min local coronary occlusion time in group I and 17.6 min aortic cross-clamp time in group II P = 0.03. Patients treated minimally invasive received significantly fewer blood transfusions (25.0% vs. 69.6% P = 0.0035) and were discharged significantly earlier from the hospital (admission rate on the fifth postoperative day 68.4% in group I vs. 100.0% in group II P = 0.0004).

CONCLUSION

We conclude that minimally invasive coronary artery bypass grafting on the beating heart in comparison to conventional single coronary artery bypass grafting during the learning curve requires longer operative times but can reduce blood transfusion requirements and hospital stay.

Cardiac troponin I to diagnose percutaneous transluminal coronary angioplasty-related myocardial injury

The purposes of the present study were to evaluate cardiac troponin 1 (cTnl) in the diagnosis of percutaneous transluminal coronary angioplasty (PTCA)-related myocardial injury in comparison with cardiac troponin T (cTnT) and creatine kinase (CK) MB mass concentration, and to investigate the frequency of myocardial injury, as indicated by myocardial protein release, after clinically symptomless side-branch occlusion (SBO) which may occur in the proximity of the attempted stenosis. The final study population comprised 80 patients undergoing elective, single vessel PTCA. Blood samples were drawn before, 6, 24 and 48 h after PTCA. cTnI, cTnT and CKMB mass baseline values were within the reference intervals in all patients (cTnI < 0.1 microgram/l, cTnT < 0.2 microgram/l, CKMB < 5 micrograms/l). Two patients presented with primary failure of PTCA, and visually successful PTCA was performed in all remaining patients. Seven patients (four with SBO) subsequently developed acute myocardial infarction (AMI). Symptomless SBO occurred in 16 patients. In controls (n = 55) there were no significant increases in cTnI, cTnT, or CKMB concentrations compared with baseline values, and all markers stayed within their reference intervals. In half the patients with symptomless SBO (n = 8) all markers were slightly to moderately increased, in two additional patients only CKMB was elevated (cTnI: 0.1-1.0 microgram/l; cTnT: 0.25-0.81 microgram/l and CKMB: 7.9-25.6 micrograms/l). In the majority of patients with primary failure or AMI we found pronounced increases in all tested markers (cTnI: 0.2-12.0 micrograms/l; cTnT: 0.44-12.10 micrograms/l; CKMB: 19.2-423.0 micrograms/l). The results of this study indicate that cTnI is comparably useful to cTnT or CKMB mass for diagnosing myocardial injury in PTCA patients. From our results a preference for one of the tested parameters cannot be clearly derived. Post-procedural cTnI, cTnT, and CKMB mass values are not higher than baseline values in uncomplicated cases, whereas AMI after PTCA leads to pronounced marker increases. SBO, even when symptomless, leads frequently (in about half the patients) to slight marker increases.

Renovascular arteriovenous differences in Lp[a] plasma concentrations suggest removal of Lp[a] from the renal circulation

High plasma concentrations of lipoprotein[a] (Lp[a]) are considered a genetically determined risk factor for atherosclerosis. Lp[a] is produced by the liver. The site(s) and mechanism(s) of catabolism are presently unclear. Lp[a] is elevated secondary to end-stage renal disease which suggests a direct or indirect role of the kidney in the metabolism of Lp[a]. We therefore investigated, by a simple in vivo approach, whether Lp[a] is removed by the human kidney. Lp[a] plasma concentrations were measured simultaneously by various methods in the ascending aorta and renal vein of 100 patients undergoing coronary angiography or coronary angioplasty. Lp[a] levels differed significantly between the two vessels even after correcting for hemoconcentration (20.1 +/- 21.6 mg/dL versus 18.7 +/- 20.3 mg/dL, P < 0.001). This corresponds to a mean arteriovenous difference of -1.4 mg/ dL or -9% of the arterial concentration. No Lp[a] or intact apo[a] could be detected in urine from healthy probands. Although we cannot assign the kidney a regulatory role for Lp[a] plasma levels in humans with normal renal function, we conclude from our data that substantial amounts of this atherogenic lipoprotein are taken up by the kidney. The underlying mechanisms are unknown at the moment. This study therefore demonstrates for the first time that the human kidney plays an active role in the catabolism of Lp[a]. This may explain the elevated Lp[a] concentrations found in patients with chronic renal insufficiency.

[Prevention of neonatal tetanus in developing countries hampered by local organization and limited knowledge of health personnel and traditional midwives; North Sulawesi (Indonesia)]

OBJECTIVE

Evaluation of the policy to prevent neonatal tetanus in North-Sulawesi (Indonesia).

DESIGN

Descriptive and questionnaire study.

SETTING

Twelve villages in the district of Minahassa, Sulawesi, Indonesia.

METHOD

The policy aimed at preventing neonatal tetanus was studied during the period April-June 1992. The relevant knowledge was tested of the community health workers (CHWs, n = 142) and traditional birth attendants (TBAs, n = 37) active in the 12 villages. To this purpose, 54 and 27 workers, respectively, were interviewed using a standard questionnaire.

RESULTS

Not all women were vaccinated sufficiently to prevent their unborn children from tetanus; mostly, adequate vaccination records were lacking. 33% of the TBAs were unaware that neonatal tetanus can be prevented by hygienic delivery; in this respect there was no difference between trained and untrained TBAs. Of the CHWs, 39% were familiar with the correct vaccination policy and 26% did not know that pregnant women have to be vaccinated. 70% of the CHWs and TBAs wrongly believed that neonatal tetanus no longer occurred in their village.

CONCLUSION

CHWs and TBAs showed little interest in neonatal tetanus, so that they were lacking in motivation regarding hygienic delivery procedures and preventive tetanus toxoid vaccination. Implementation of a good preventive programme in developing countries mostly requires organizatory rather than biomedical improvement.

[Complications during directional coronary atherectomy (DCA): catheter fracture between housing assembly and shaft point with subsequent vascular occlusion]

Directional coronary atherectomy of a severe stenosis of the left anterior descending coronary artery was complicated by device fracture between the cylindric housing portion and the distal nose-cone collecting chamber. After successful removal of the DCA device, an early occlusion of the coronary vessel occurred, which could be successfully treated by perfusion balloon catheter.

Side-branch occlusion during percutaneous transluminal coronary angioplasty

Concentrations of creatine kinase (CK) MB mass and cardiac troponin T were measured in serial peripheral venous blood samples from 21 patients who underwent percutaneous transluminal coronary angioplasty (PTCA). Angiography showed side-branch occlusion during PTCA without clinical signs of myocardial injury in 5 patients. After PTCA, CKMB mass concentrations were substantially higher than normal in all 5 patients with side-branch occlusion, and troponin T concentrations were high in 3. By contrast, only 2 patients and 1 patient, respectively, without side-branch occlusion had slight rises in CKMB and troponin T. Release of the contractile protein troponin T reflects more severe damage to myocytes than simple leakage of CKMB. Therefore, myocardial damage induced by side-branch occlusion can be graded by measurement of troponin T in plasma.

[The value of CT and MRT in assessing aortocoronary venous bypasses in comparison with coronary angiography]

In a follow-up study of 20 patients with a total of 52 aortocoronary venous bypass grafts (ACVB) three months after surgery, the patency of the grafts was assessed by magnetic resonance tomography (MR) followed by contrast enhanced CT-scan and selective coronary angiography on the following day. Each examination was interpreted independently and immediately after the procedure for the visibility and patency of the grafts. The statistical figures for the non-occluded grafts showed a sensitivity of 90.24% and a specificity of 54.54% for the CT scans and a sensitivity of 73.17% with a specificity of 72.72% for the MR. Although the sensitivity of the CT is somewhat higher than that of MR, neither procedure offers a clear advantage over each other and neither of both methods alone is adequate for the assessment of ACVB's. They are therefore only valuable as an adjunct to clinical data and as a screening procedure for selective coronary angiography.

[Mitochondria number as a prognostic parameter in dilated cardiomyopathy. A long-term follow-up study]

According to morphological criteria of the myocardium, patients with clinical and hemodynamic signs of dilated cardiomyopathy were divided into three groups. Group I: patients with 1-2 mitochondria per 2 sarcomeres (n = 46); Group II: patients with more than 2 mitochondria per 2 sarcomeres (n = 47); Group III: patients with histological findings of myocarditis in the past (n = 33). Mean follow-up in groups I, II, III was 29, 22, 26 months, respectively (6-58, 3-52, 3-62/median 29, 18, 22). Clinical parameters were evaluated at the beginning and at the end of the prospective observation and were classified clinically as "improved, unchanged, deteriorated"; "heart transplantation", "death of cardial causes", "death of other than cardial causes" or "lost to follow up" were the other endpoints of the observation. At the beginning there were no hemodynamic differences between groups I, II, III, except significant difference in ejection fraction and mean ventricular shortening velocity between groups I and II. Scored together with the clinical symptoms "deterioration" and "death of cardial causes" as endpoints, survival rates without event up to 5 years in group I were 83 +/- 7% compared with group II 33 +/- 13% and group III 86 +/- 8%. There were significant differences (p less than 0.01). We conclude that the increased number of mitochondria per 2 sarcomeres in biopsy specimen of patients with dilated cardiomyopathy can be a significant parameter of deteriorated prognosis.

[Quantitative computed tomographic flow measurements of aortocoronary venous bypass grafts. II. Correlation with angiographic measurements]

In 26 patients with 35 aortocoronary venous bypass grafts (ACVB) quantitative invasive angiographic parameters were compared with flow parameters of contrast medium, assessed by computed tomography. Out of seven different CT-parameters, the maximum decrease of concentration of contrast medium (40 +/- 5 HE/sec; mean +/- SEM) showed a correlation with the angiographic parameter of contrast medium quantitative flow rate (7.2 +/- 0.5 cm/sec) and this correlation (r = 0.536/SEE = 23.17) is significant (p less than 0.001). We conclude that for the single patient assessment of quantitative flow in ACVB by CT with a 3-second repetition rate could be performed with limited accuracy.

[Decrease in left ventricular stroke performance following bypass of a significant main coronary artery stenoses]

Hemodynamic parameters and left ventricular function were assessed 14 +/- 4 (means +/- SEM) days preoperatively and 101 +/- 5 days after aortocoronary bypass surgery in eight men (51-65 years of age) with left main coronary stenosis (greater than or equal to 75%). Working capacity on bicycle exercise stress test increased from 43 +/- 7 to 68 +/- 7% of age-, and body-surface matched normals; at the same time cardiac output (thermodilution) decreased from 5.7 +/- 0.5 to 4.7 +/- 2 l/min (p less than 0.05), stroke volume decreased from 78 +/- 6 to 63 +/- 3 ml (p less than 0.01), stroke work from 1.16 +/- 0.10 to 0.89 +/- 0.07 Joule (p less than 0.001), and stroke power from 4.0 +/- 0.3 to 3.4 +/- 0.2 Joule/s (p less than 0.01) postoperatively. Left ventricular volumes decreased postoperatively but not significantly, ejection fraction remained unchanged (57 +/- 13/59 +/- 13%). A control group (PTCA of LAD) showed no significant changes of these parameters. As all patients had a good postoperative result, decrease of stroke work after aortocoronary bypass surgery is not necessarily an expression of postoperative deterioration, since it can coincide with good left ventricular function, angiographically successful revascularization, and an increase in working capacity.

[Cardiokymography: relative quantification of results in normal probands]

The main problem with cardiokymography (CKG) and the principal reason for its limited clinical application to date is the deficiency of calibration and quantification of results. We tried to improve the value of the procedure by quantification of the results in 14 healthy young men (age: 23, 18-31 years) in place of subjective assessment. Before and after a bicycle exercise stress test CKG tracings were obtained in a lying position at rest, immediately after exercise and after recovery. Two different methods were applied to quantify the CKG tracings (distance method and area method). The relative height of the curves at rest was 89 +/- 72% (68 +/- 39%), immediately after exercise 111 +/- 60% (73 +/- 27%) and, after recovery 121 +/- 88% (78 +/- 49%). The relative change in the height of the curves between rest and exercise was not significant according to both methods (+22 +/- 64%/+5 +/- 32%), but the variation of values in an individual patient between rest and exercise was large. Interobserver variability was rather large, according to two independent investigators. Hence, it was not possible to establish limits of normal values in quantitative CKG, but only mean values.