Spectrum, and clinical and functional implications of UNC13D mutations in familial haemophagocytic lymphohistiocytosis.

OBJECTIVE: Familial haemophagocytic lymphohistiocytosis (FHL) is a fatal disorder of immune dysregulation with defective cytotoxic lymphocyte function. Disease-causing mutations have been identified in the genes encoding perforin (PRF1), syntaxin-11 (STX11), and Munc13-4 (UNC13D). We screened for UNC13D mutations and studied clinical and functional implications of such mutations in a well defined patient cohort. METHODS: Sequencing of UNC13D was performed in 38 FHL patients from 34 FHL families in which PRF1 and STX11 mutations had been excluded. RESULTS: We identified six different mutations affecting altogether 9/38 individuals (24%) in 6/34 (18%) unrelated PRF1/STX11-negative families. Four novel mutations were revealed; two homozygous nonsense mutations (R83X and W382X), one splice mutation (exon 28), and one missense mutation (R928P). In addition, two known mutations were identified (R214X and a deletion resulting in a frame-shift starting at codon 782). There was considerable variation in the age at diagnosis, ranging from time of birth to 14 years (median 69 days). Three of nine patients (33%) developed central nervous system (CNS) symptoms. Natural killer (NK) cell activity was impaired in all four patients studied. Defective cytotoxic lymphocyte degranulation was evident in the two patients investigated, more pronounced in the patient with onset during infancy than in the patient with adolescent onset. CONCLUSIONS: Biallelic UNC13D mutations were found in 18% of the PRF1/STX11-negative FHL families. Impairment of NK cell degranulation was less pronounced in a patient with adolescent onset. FHL should be considered not only in infants but also in adolescents, and possibly young adults, presenting with fever, splenomegaly, cytopenia, hyperferritinaemia, and/or CNS symptoms.

Physiology of erythropoietin during mammalian development.

UNLABELLED: Growth is a fundamental process of mammalian development. Several observations regarding regulation of erythropoiesis during growth are not easily explained by the hypoxia-erythropoietin (Epo) concept. This review focuses primarily on this aspect of the physiology of Epo. The question is raised of whether this regulation during growth is based on the hypoxia-Epo mechanism alone, or whether Epo acts in concert with general growth-promoting factors, particularly growth hormone (GH) and the insulin-like growth factors (IGF-I and -II). Supporting the latter hypothesis is the observation that the Epo and GH/IGF systems are activated by hypoxia and share similar receptors and pathways. Recent studies indicate that human fetal and infant growth is stimulated by GH, IGF-I and IGF-II. Epo, GH and IGFs are expressed early in fetal life. Although the rate of erythropoiesis in the fetus is high, serum Epo levels are low. The Epo response to hypoxia in the fetus and neonate is reduced compared with adults. Following delivery the Epo levels vary between species, probably related to the oxygen transport capacity of the hemoglobin (Hb) mass. IGF-I levels are low in the fetus and increase slowly following birth, except in preterm infants in whom the levels decline. In all mammals Hb declines following birth, giving rise to "early anemia". Except in the human, Epo levels increase proportionally with the fall in Hb, but there is a discrepancy between the curves for serum immunoreactive Epo (siEpo) and for erythropoiesis stimulating factors (ESF): the latter include other stimulatory factors in addition to Epo. Hypertransfusion of mice in the period of "early anemia" suppresses siEpo, but not ESF and erythropoiesis, as it does in adult mice. GH and IGF-I have direct effects on erythropoiesis in vitro and act particularly at the later stages of red cell differentiation. IGF-I acts synergistically with Epo, and its effects are most marked when Epo levels are low. Human recombinant (rhu) IGF-I stimulates erythropoiesis in neonatal rats, but not in newborn mice and lambs. In adult mice, in hypophysectomized rats and in mice with end-stage renal failure, however, a stimulatory effect of this growth factor was found on red cell production. RhuGH stimulates erythropoiesis in GH-deficient short children. CONCLUSION: Fetal and early postnatal erythropoiesis are dependent on factors in addition to Epo. The likely candidates are GH and IGF-I. The in vitro stimulating effects of these factors on erythropoiesis are convincing, but more data are needed on the in vivo effects.

Shift from fetal to adult hemoglobin production in a preterm infant after exchange transfusion: a quantitative approach.

To evaluate the quantitative aspects of the shift in production from fetal hemoglobin (HbF) to adult hemoglobin (HbA), the HbF and HbA mass were estimated in a preterm infant (gestational age 29 weeks) for 22 weeks after an exchange transfusion the second day of life, leading to an initial HbA% of 100. Up until the estimated time of delivery, the HbA mass declined continuously, at a rate corresponding to a survival time of the transfused HbA erythrocytes of 100 days, and the rise in total hemoglobin mass could be ascribed solely to a rise in the HbF mass. HbF% maximum was reached 3 weeks before HbF mass maximum, and, thus, the HbF% and HbA% time courses gave no basis for evaluation of the production/destruction balance of HbF and HbA erythrocytes. The applied quantitative approach seems to be a useful additional procedure for evaluating the switch from HbF to HbA production and for estimating HbA erythrocyte survival time in preterm infants.

Sibs with Ritscher-Schinzel (3C) syndrome and anal malformations.

Ritscher-Schinzel syndrome (cranio-cerebello-cardiac syndrome, 3C syndrome) is a recently delineated disorder with Dandy-Walker malformation, congenital heart defects, and characteristic face. Various other defects, including eye and kidney malformations, have been described in the few patients reported. Here we describe 3 sibs born to consanguineous Pakistani parents with 3C syndrome. All 3 children had atrial septal defects II and ventricular septal defects and died within 3 months. Two of them had a Dandy-Walker malformation, whereas 1 had only slightly dilated ventricles. One sib had anal atresia, and another a ventrally displaced anus. The findings in the 3 sibs demonstrate the intrafamilial variation in the Ritscher-Schinzel syndrome, because the second sib did not have a Dandy-Walker malformation. Anal anomalies have not been previously reported as a component manifestation of the disorder. The occurrence of 3 affected sibs in a consanguineous family confirms autosomal recessive inheritance.

Effect of low and moderate doses of recombinant human erythropoietin on the haematological response in premature infants on a high protein and iron intake.

UNLABELLED: There is no consensus regarding protein intake and the doses of recombinant human erythropoietin (r-HuEpo) and iron in the treatment of anaemia of prematurity (AOP). This open, randomized study has compared the effectiveness of 50 IU r-HuEpo/kg with that of 100 IU/kg, both given subcutaneously thrice weekly. In addition, two different protein supplements have been compared; lyophilized human milk protein and a commercial cow's milk product. Total protein intake was 3 g/kg per day. Daily iron dose was 18-36 mg. "Healthy" preterm infants (n = 32, birth weight: 800-1400 g, gestational age < or = 31 weeks) were studied from age 3 to 8 weeks. The two protein regimens yielded no differences in body growth, reticulocyte count or Hb concentration. In both r-HuEpo dose groups increased number of reticulocytes followed start of treatment; higher levels were, however, found in the group receiving 100 IU/kg. Mean Hb concentration plateaued at 12 g/dl for infants receiving 100 IU/kg, at 11 g/dl in the 50 IU/kg group. Even though serum levels of ferritin and transferrin saturation indicated no iron deficiency, soluble transferrin receptor increased in both groups, more rapidly and to higher levels in the 100 IU/kg group. In addition, the number of infants having more than 8% hypochromic red cells increased in both groups. CONCLUSIONS: Commercial cow's milk protein added to human milk was as good as human milk protein supplementation in supporting growth and erythropoiesis. Fifty IU/kg r-HuEpo thrice weekly during AOP stimulated erythropoiesis significantly, but less so than 100 IU/kg. Even when using high oral doses of iron to preterms receiving r-HuEpo, our data suggested a certain degree of iron deficient erythropoiesis.

Parenteral iron increases serum erythropoietin concentration during the "early anaemia' of 10-20-day-old mice.

Parenteral iron abolishes the "early anaemia' in all mammals tested and increases packed cell volume (PCV) and haemoglobin concentration (Hb) significantly above adult levels. In the present study we examined the effect of parenteral iron upon serum immunoreactive erythropoietin (siEpo) concentration in young mice (age 6-24d) and in adult iron-deficient mice. Young BALB/CJ mice, from 5 to 23 d of age, and adult (60-100 d old)mice, some of which were iron deficient due to a low iron diet from the time of weaning, were given iron subcutaneously (iron sorbitol, Fe+3, 1.2 mg iron/100g body weight/injection). Iron was given as one single dose and the animals killed 20-24 h later. Control mice were similarly treated with saline. In young mice, from the age 10 d to weaning at 20 d, the siEpo level, measured 20-24 h after a single subcutaneous dose of iron, was 5 times greater than that in control mice (P < 0.0001). In contrast, there was no change in siEpo 20-24 h after a single subcutaneous dose of iron in adult mice, whether iron-deficient anaemic or normal. Thus, during the "early anaemia' in young mice over 10 d old, iron increased siEpo levels, whereas it had no such effect in iron-deficient and normal adult mice. This suggests that between ages 10 and 20 d, iron has additional effects in the regulation of erythropoiesis, which may not occur in adult or in 6-d-old mice.

Erythropoietin (Epo), protein and iron supplementation and the prevention of anaemia of prematurity: effects on serum immunoreactive Epo, growth and protein and iron metabolism.

The effect of recombinant human (r-Hu) erythropoietin (Epo) (300 IU/Kg per week for 4 weeks) was studied in healthy preterm infants (n = 14) fed human milk with additional milk protein and high doses of iron. The controls (n = 15) were in themselves a study group and were used to follow the natural course of anaemia of prematurity on such nutrition. Serum immunoreactive Epo (SiEpo) increased significantly 24 h after r-HuEpo injections (range 36 to > 128 mU/ml) and remained at these levels throughout the treatment period. r-HuEpo in such moderate doses kept haemoglobin above 11 g/dl. Bodyweight gain, protein and iron parameters indicated adequacy of dietary protein and iron. In controls, siEpo increased during the first weeks after nutritional supplementation, with a concommitant rise in reticulocyte count. At age 3 weeks, despite low siEpo levels, reticulocyte counts indicated active erythropoiesis. Following further moderate increases in siEpo, the reticulocyte count increased to high levels (7%). The reticulocyte response suggests that erythropoiesis in preterm infants is less dependent upon Epo levels than in adults.

Effects of recombinant human erythropoietin on fetal and adult hemoglobin in preterm infants.

In the present study we assess the effect of recombinant human erythropoietin (r-HuEpo) upon levels of fetal Hb (HbF) and adult Hb (HbA) in preterm infants. Twenty-eight "healthy," appropriate for gestational age infants with birth weights 900-1400 g entered the study at 3 wk of age. Fourteen infants were randomized to receive r-HuEpo, and 14 infants served as controls. Four controls and six r-HuEpo treated infants had been transfused before study start, whereas four control infants were transfused in the course of the study. The untransfused infants showed a high HbF/Hb ratio during the study with only a weak tendency to decline toward the expected time of delivery. The total Hb mass increased (p < 0.05) more in the r-HuEpo-treated infants than in the untreated, whereas the rise in HbF mass was similar in the two groups. After each transfusion, the HbF/Hb ratio reverted gradually to the ratio expected at the infant's postconceptional age. There was no difference in the production rate of HbF between r-HuEpo-treated infants and controls. The present data indicate that the HbF/HbA ratio in preterm infants is subject to the same programmed mechanisms which govern intrauterine erythropoiesis until term and that exogenous r-HuEpo does not influence this pattern significantly.

[Antipsychotic agents and pregnant women. A case report]. / Antipsykotika og gravide. En kasuistikk.

Teratogenic effects of drugs are not limited to visual malformations but also include developmental disturbances. Probably drugs that inhibit nerve signals such as dopamine in the central nervous system can affect the maturing of the foetal brain in the last trimester and in the postpartum period, as shown in animal studies. We have observed an infant girl with psychomotoric disturbances which occurred at the age of two weeks. The mother had received 108 mg perfenazin decanoate intramuscular injections four times during the second and third trimester, the last two times were three weeks and two days before delivery, which was at term. The symptoms resembled tardive dyskinesia. Periodically the baby showed restlessness and uttered high-pitched cries. The literature on neuroleptics indicates no major teratogenic risk, but possible risk of behavioural teratogenicity. We recommend greater caution in connection with prescribing neuroleptics in pregnancy.

Effects of the luteinizing hormone-releasing hormone agonist leuprolide on lipoproteins, fibrinogen and plasminogen activator inhibitor in patients with benign prostatic hyperplasia.

The impact of chronic administration of the luteinizing hormone-releasing hormone agonist leuprolide depot on cardiovascular risk factors was investigated in a controlled double-blind study comprising 50 evaluable patients with benign prostatic hyperplasia. In the 26 patients receiving leuprolide the mean total cholesterol level increased by 10.6%, high density lipoprotein cholesterol by 8.2% and triglycerides by 26.9% (p = 0.003, 0.052 and 0.050, respectively). Low density lipoprotein cholesterol levels were unchanged. Apolipoprotein A1 increased by 13.2% (p = 0.001), while apolipoprotein B, fibrinogen, thrombocytes and plasminogen activator inhibitor were unchanged. Hemoglobin decreased by 1.2 gm./100 ml. without a concomitant decrease in serum erythropoietin concentration. These changes act in different directions with regard to cardiovascular risk and the overall effect is difficult to assess.

Recombinant human insulin-like growth factor 1 (rh-IGF-1) stimulates erythropoiesis in adult, but not in newborn mice.

The in vivo effect of recombinant human insulin-like growth factor (rh-IGF-1) upon erythropoiesis was studied in inbred BALB/C mice. Unweaned, rapidly growing 20 days old mice and adult female mice received subcutaneous rh-IGF-1 or control injections every 6 h for 48 h. The mice were killed either 12 or 48 h after the last injection, i.e. a study time of 60 and 96 h, respectively. Bone marrow erythroid colony forming units (CFU-E), reticulocytes, haematocrit, serum immunoreactive erythropoietin (siEPO) and body and organ weight were measured. An additional group of young mice were given iron prior to the rh-IGF-1 injections to ensure sufficient available iron. No differences in overall body or organ weights were observed. In the young mice erythropoiesis as measured by bone marrow CFU-E, reticulocytes and haematocrit did not differ between rh-IGF-1 group and controls. When iron alone was given, reticulocytes (P < 0.05) and haematocrit (P < 0.0001) increased significantly, but no further stimulation was seen when rh-IGF-1 injections were given in addition to iron. The adult female mice responded with significantly increased erythropoiesis as judged by increased reticulocyte counts following rh-IGF-1 injections (P < 0.001). No significant effect upon CFU-E and haematocrit was detected. The reticulocyte response was more pronounced at 96 than at 60 h after the first rh-IGF-1 injection. SiEPO was significantly (P < 0.01) lower in the adult 96 h rh-IGF-1 group than in the appropriate control group. In conclusion parenteral iron significantly increased haematocrit in unweaned mice. Short time rh-IGF-1 treatment did not stimulate erythropoiesis in these rapidly growing mice, whether or not iron supplementation had been given.(ABSTRACT TRUNCATED AT 250 WORDS)

Erythropoietin, protein, and iron supplementation and the prevention of anaemia of prematurity.

The effectiveness of recombinant human erythropoietin (r-HuEpo) in raising haemoglobin concentrations in very low birthweight infants was examined in a randomised multicentre study. Twenty nine 'healthy' appropriate for gestational age infants with birth weights 900-1400 g entered the study at 3 weeks of age. All infants received breast milk supplemented with 9 g/l human breast milk protein from 3 to 8 weeks of age. Eighteen mg iron was given daily from week 3 and was doubled if serum iron concentration fell below 16.0 mumol/l. Fourteen infants were randomised to receive 100 U/kg r-HuEpo subcutaneously three times a week from week 3 to week 7; 15 infants served as controls. After one week reticulocyte and haemoglobin concentrations were significantly higher in the r-HuEpo treated group and the haemoglobin values remained significantly higher throughout r-HuEpo treatment and at the concentrations observed in full term infants. No adverse effects were associated with the treatment. In stable very low birthweight infants with optimal iron and protein intakes, moderate dose r-HuEpo can produce significant gains in red cell production that may be clinically useful.

Unreliability in immunoassays of erythropoietin: anomalous estimates with an assay kit.

We report the finding of inappropriately high estimates of erythropoietin (Epo) in 11% of serum samples tested by one commercial assay kit. These estimates were not confirmed when the same samples were tested independently in four other systems for the immunoassay of Epo. As yet no explanation has been found to account for the anomalously high estimates.

Growth hormone treatment and development of malignancy: recombinant human growth hormone does not induce leukemia in AKR/O-mice.

In 1988 several reports described leukemia in former/present growth hormone (GH)-treated children, and a doubled incidence of leukemia in GH-treated children was concluded in a workshop in Bethesda. A mouse strain (AKR/O) with a high incidence of leukemia was used as a model. AKR/O-mice in the preleukemic adult age and younger mice during rapid growth were treated with recombinant human GH (rhGH) in human therapeutic doses to see whether this treatment would affect the time and presentation of malignant disease. The malignant development did not appear earlier or in a different way in the animals receiving rhGH from day 6 to 50 than in their appropriate controls. A borderline protective effect to the development of leukemia was seen in the adult group receiving rhGH; in this group antibodies to hGH also developed. We conclude that in this experimental model human therapeutic doses of rhGH do not influence the development of malignancy in the AKR/O mice.

[Transportation of newborn infants. A 6-year case load]. / Transport av nyfødte. Et seks års materiale.

We have evaluated neonatal transports to Ullevål hospital over a six-year period. These were either carried out by helicopter, using a trained transportation team, or by ambulance, the transport being improvised from one transport to another. The investigation shows great variation in the handling of the transports, with the most significant problems in the group without a structured transport system. In addition to generally rather casual and often hazardous transport, particular problems arose in connection with maintaining an adequate body temperature. In addition, the transports were very inadequately documented.

[Hearing loss among children in Oslo]. / Hørselhemmede oslobarn.

The study concerns children born the years 1975-84. Only children in need of hearing aids are taken into account. The incidense was 1.08 per 1,000 live born children. The prevalens in January 1988 was 1.57 per 1,000 children, including 18 children moving into the city. The etiology among 75 children was 47% prenatal, 16% perinatal, 11% postnatal defects and further 26% of unknown neurogenic origin. Among the 63 impaired children living in Oslo 1988 15 or 24% had multiple handicaps. Identification of hearing loss before one year of age increased from 23% for children born 1975/79 to near 60% for children born 1980/84. At risk children should be tested before leaving hospital after delivery.