R. Lorini

Preferential Maternal Derivation in Inv Dup(15) Analysis of Eight New Cases

SummaryEight patients are reported with a de nov extra inverted duplicated chromosome 15. The abnormal chromosome was considered to be the same in all cases, but its precise delineation remained uncertain and was defined as either 15qter→15q12::15q12→15pter or 15pter→15q11::15q13→15pter. Analysis with various techniques of the satellite regions of the bisatellited chromosomes demonstrated maternal derivation in six and paternal derivation in one of the seven families. A nonsister chromatid exchange between the two homologous chromosomes 15 is considered a likely origin of the inv dup(15) in the cases with maternal derivation; in the only case of paternal derivation, however, the abnormal chromosome originated from one single chromosome 15. The clinical findings confirm that patients with inv dup(15) have mental and developmental retardation and are frequently affected by seizures, while severe physical malformations are absent.

Autoimmunity, HLA, Gm AND Km Polymorphisms in Turner's Syndrome

Considering the high frequency of autoimmune disorders in Turners syndrome and the close relationship between autoimmunity, HLA and immunoglobulin constant region gene polymorphisms, we studied 46 patients with Turners syndrome, by determination of autoantibodies, HLA histoglobulins and Gm and Km allotypes. OSA and in particular PCA resulted significantly more frequent in patients than in the controls. A higher frequency of HLA-A31, B38 antigens and of blanks at HLA-A locus was found in Turners subjects than in the controls. A31 was significantly more frequent in autoantibody positive patients while B38 was more frequent in autoantibody negative Turners subjects than in the controls. DR4 antigen was present only in autoantibody negative patients. Gm 3; 23; 5* phenotype was significantly less frequent, while Gm 3;..; 5* phenotype was more frequent in patients than in controls. Our data confirm the higher incidence of autoimmunity disorders in Turners syndrome than in normal subjects. Particular HLA and immunoglobulin types seem to mark this condition. The increase in the blank frequency at A locus could be explained by the presence of a rare antigen at HLA-A locus or a particularly elevated homozygous condition in these subjects.

Auto-immunity in children with diabetes mellitus and in their relatives.

Islet cell antibodies (ICA-IgG and complement-fixing-ICA), parietal cell antibodies (PCA), intestinal epithelial cell antibodies (IECA), thyroglobulin (TgA) and thyroid microsomal antibodies (MsA), antinuclear (ANA) and reticulin antibodics (RA), were studied in 55 insulin-dependent diabetic patients (30 males and 25 females), aged 2–19 years with diabetes from a few days up to 14 years. In 58% of the diabetics one or more autoantibodies were found: ICA-IgG (31%), CF-ICA (16%), PCA (34%), TgA (9%), MsA (9%), ANA (13%), RA (2%). Autoantibodies were significantly more frequent in females (76%) than in males (43%) (P<0.025). ICA-IgG, CF-ICA, PCA, ANA were significantly more frequent in patients than in controls. The frequency of ICA-IgG and CF-ICA was significantly higher during the first 3 years of disease than afterwards (P<0.001); a similar pattern was observed for PCA, TgA, MsA. Of the 87 parents and 30 siblings screened for ICA-IgG, CF-ICA, PCA, IECA, TgA, MsA, ANA and RA, 42 (44%) had one or more autoantibodies, which were more frequent in females than in males. Seven relatives (6%) were ICA-IgG positive (four mothers, two fathers and one brother), and only one mother, ICA-IgG negative, was CF-ICA positive. Other autoantibodies were also more frequent in parents than in controls. Autoantibody-positive relatives have been asymptomatic up to now.

Celiac disease and type I (insulin-dependent) diabetes mellitus in childhood: follow-up study.

To ascertain the specificity of IgA and IgG antigliadin (IgA-AGA, IgG-AGA), IgA-antireticulin (R1-ARA), and antiendomysial (AEA) antibodies for the diagnosis of celiac disease, we evaluated 133 type I diabetic children aged 1.4-28.4 years (mean 14.1 +/- 6.6), with diabetes from onset to 20.5 years. Fifty-three patients were considered at onset and 49 of these also during follow-up. IgA-AGA and IgG-AGA were determined by enzyme-linked immunosorbent assay (ELISA), R1-ARA and AEA by indirect immunofluorescence. IgA-AGA were positive in 20 of 133 (15%), IgG-AGA were positive in seven of 133 (5.26%), while R1-ARA and AEA were positive in three patients. At the onset of disease we found elevated IgA-AGA in 17 of 53 (32%) patients, IgG-AGA in four (7.55%) patients, three of them with IgA-AGA as well; R1-ARA and AEA were present in three (5.66%) patients, all with high IgA-AGA levels. During 1-10 year follow-up IgA-AGA decreased to within the normal range in 13 patients, with elevated IgA-AGA at onset but without R1-ARA and AEA; in four patients with high IgA-AGA at onset, IgA-AGA remained constantly elevated as did R1-ARA and AEA in three of them; and two patients, without IgA-AGA, R1-ARA, and AEA at onset, became positive for all three antibodies. Intestinal biopsy confirmed a diagnosis of celiac disease in five of these with IgA-AGA, R1-ARA, and AEA, but not in one patient with persistent IgA-AGA but no AEA and R1-ARA, suggesting that R1-ARA and AEA are more reliable markers for the screening of celiac disease in type I diabetic patients.

Cytotoxic activity in children with insulin-dependent diabetes mellitus

We determined the percentage of circulating natural killer (NK) cells, using the monoclonal antibodies anti-CD57 and anti-CD16, NK cytotoxic activity (lytic units/10(6)) and lymphokine-activated killer (LAK) activity in 25 IDDM patients aged 3-23 years, 12 with disease for < 1 year (Group I) and 13 with disease for > 3 years (Group II). Nine age-matched healthy subjects served as controls. The percentage of CD57+ cells was similar in IDDM patients and controls, while the percentage of CD16+ cells was lower in IDDM patients (P < 0.05) than in controls. NK cell cytotoxic activity was lower in IDDM patients than in controls (P < 0.01), in Group I and II compared with controls (P < 0.005). LAK activity was similar in IDDM patients and in controls. No correlation was found between NK cytotoxic activity and metabolic control, HLA typing, while a negative correlation was found between NK cytotoxic activity and insulin requirement (P < 0.05). The decreased NK cytotoxic activity observed in our patients, in particular in long-standing diabetics, with normal NK cell number, could be due to a qualitative defect of the NK cells, or to a deficient IL-2 and/or TNF-alpha production, or to a immunomodulatory or immunosuppressing effect of insulin.

Anticardiolipin antibodies in children and adolescents with insulin-dependent diabetes mellitus

Anticardiolipin antibodies were determined in 29 diabetic children and adolescents, aged 3.9–26.8 years, with disease duration from 1 month to 19 years. Anti-islet cell antibodies (ICA-IgG and CF-ICA), anti-insulin antibodies (IAA), antithyroid antibodies and non organ-specifc (NOSA) antibodies were also determined. Patients were grouped according to insulin-dependent diabetes mellitus (IDDM) duration: group I (n=11)<6 months, and group II (n=18)>5 years. Eleven of group II patients showed precocious signs of micro-angiopathic complications. Forty-two age- and sex-matched healthy subjects served as controls. IgG and IgM anticardiolipin antibodies were evaluated by ELISA and their results expressed as arbitrary units (AU). IgG anticardiolipin antibodies were found in 7 patients (24%), while IgM anticardiolipin antibodies were absent in all. IgG anticardiolipin antibodies were more frequent in IDDM patients than in controls (P<0.005) and group I (in 6 out of 11 patients; 54.5%) than in group II (in 1 out of 18 patients; 5.5%) (P<0.025). In five out of six group I patients with IgG anticardiolipin antibodies, ICA-IgG and/or CF-ICA were also found. No correlation was observed between anticardiolipin and other auto-antibodies, micro-angiopatic complications, and HLA typing.

HLA and immunoglobulin polymorphisms in idiopathic dilated cardiomyopathy

Dilated cardiomyopathy (DCM) is an idiopathic heart muscle disorder. The presence of circulating cardiac antibodies and the association with HLA-DR4 are consistent with autoimmune pathogenesis in a subset of patients. Sixty-eight DCM patients and 277 controls were typed for IgG heavy-chain constant region (Gm) and kappa light-chain (Km) allotypes. All patients and 210 of the 277 controls were HLA-DR typed. The Gm (1, 3, 17; 23; 5*, 21, 28) phenotype was overrepresented in DCM compared with controls (25% vs 13%, p = 0.0139, pc = NS, RR = 2.23). The frequency of this phenotype was higher in patients with younger age at onset, shorter symptom duration, and among those who were positive for cardiac as well as for non-organ-specific autoantibodies than in controls. A higher frequency of the Gm (1, +/- 2, 3, 17; +/- 23; 5*, 21, 28) heterozygous phenotypes was also found in DCM compared to controls (40.91% vs 26.89%; p = 0.02, pc = 0.04, RR = 1.88). The finding of Gm heterozygosity in DCM was associated with serum positivity for cardiac antibodies. A higher proportion of DCM patients were positive for both the Gm (1, 3, 17; 23; 5*, 21, 28) phenotype and HLA-DR4 compared to normals (3/68 vs 0/210; p = 0.04, RR = 22.50).(ABSTRACT TRUNCATED AT 250 WORDS)

Alterations of in vitro interleukin 1 and 2 in diabetic children

We studied interleukin 1 (IL-1) and interleukin 2 (IL-2) production in unstimulated and stimulated cultures from 27 young diabetic patients and 21 age-matched healthy subjects. In unstimulated cultures monocytes from newly diagnosed patients produced significantly higher levels of IL-1 than controls. In lipopolysaccharide (LPS)-stimulated cultures, IL-1 production in patients with fresh and long-standing diabetes was no different from that of controls. IL-2 production was low or absent in unstimulated cultures from insulin-dependent diabetes mellitus (IDDM) patients and controls. In phytohaemagglutinin (PHA)-stimulated cultures both patient groups produced significantly less IL-2 than controls. No correlation was observed between IL-1, IL-2 production and HbA1 levels or the presence of HLA-DR3 or DR4. Our data on “spontaneous” IL-1 production support the hypothesis that monocytes from some newly diagnosed IDDM patients may circulate in a “preactivated” state. The low levels of IL-2 might be explained by an abnormal consumption or by the presence of increased soluble IL-2 receptor levels or by a serum factor which interferes with IL-2 production. Alternatively, it may be a genetically determined trait.

Low Serum Levels of Tumor Necrosis Factor-Alpha in Insulin-Dependent Diabetic Children

We measured serum levels of tumor necrosis factor-alpha (TNF-alpha) in 48 children with insulin-dependent diabetes mellitus (IDDM), divided into two groups according to disease duration (group I < 6 months and group II > 3 years): group I 15 patients, aged 2.2-13.7 years, and group II 33 patients, aged 4.5-25.5 years. Thirty-six age- and sex-matched healthy subjects served as controls. TNF-alpha levels were measured by immunoradiometric assay. We found that TNF-alpha levels were lower in all IDDM patients (29.65 +/- 3.83 pg/ml) than in controls (74.74 +/- 10.17 pg/ml) (p < 0.0001), as well as in group I (24.07 +/- 3.65 pg/ml) and group II (32.16 +/- 5.29 pg/ml) as compared to controls (p < 0.001). TNF-alpha levels were significantly lower in patients with antibodies than in those without antibodies and in controls. Similar results were found in longstanding IDDM patients. No correlation was found between serum TNF-alpha and chronologic age, duration of disease, metabolic control, insulin requirement and HLA typing. During a 1-year follow-up study in 12 group I patients no significant variations in TNF-alpha levels were observed. It has been reported that the administration of exogenous TNF suppresses the development of diabetes in nonobese diabetic mice, low producers of endogenous TNF. The results suggest that aberrant TNF-alpha synthesis may contribute to immune dysregulation thus favoring the development of autoimmune diseases.

ANTIPITUITARY ANTIBODIES IN PATIENTS WITH PITUITARY ABNORMALITIES AND HORMONAL DEFICIENCY

Sirs, Mau et al. (1993) reported the results of antipituitary hormone autoantibodies (APHA) in adult patients, six with primary empty sella syndrome (ESS) and five with pituitary tumours identified by magnetic resonance (MR) imaging or computed tomography scan, compared to those of six normal volunteers. Five patients (45Y0), two with ESS and three with pituitary tumour, had positive APHA which did not correlate with the type of hormonal deficiency present, indicating that they are neither specific nor predictive. We studied 45 hypopituitary patients (29 male and 16 female) aged 3-22 years (mean age 12.4k4.0 years) and determined pituitary antibodies by indirect immunofluorescence on unfixed cryostat sections of monkey pituitary. All were examined by MR (Maghnie et al., 1991) which revealed anterior pituitary abnormalities in 34 of them. In particular, 22 (group I, mean age 14.3 f4.9 years) had anterior pituitary hypoplasia, invisible pituitary stalk and ectopic posterior pituitary, nine with isolated GH deficiency (IGHD) and 13 with multiple pituitary hormone deficiency. Twelve (group 11, mean age 9.9 & 2.8 years) had isolated anterior pituitary hypoplasia and IGHD. Eleven (group 111, mean age 12.2 3: 1.4 years) had normal morphology of pituitary gland and IGHD. The period of GH treatment before antipituitary antibodies evaluation was 0.2-94 years (mean 5.8 3.4 years) in group I, 0.2-7.2 years (mean 2.7f2.6 years) in group I1 and 1.2-6.9 years (mean 2.4 f1.6 years) in group 111. In two patients of group 11, the evaluation was made at diagnosis of GH deficiency before the beginning of GH treatment. Antipituitary antibodies were positive in one girl with the adults, even though they are not specific. To find the real meaning, however, in terms of physiopathology and mechanisms requires more investigation. In our study antipituitary antibodies were negative in the presence of pituitary abnormalities. In particular, in children with pituitary insufficiency, empty sella (ES) is considered an epiphenomenon of anterior pituitary hypoplasia (Maghnie et al., 1990); the absence of antipituitary antibodies strengthens the hypothesis that ES in children may be an entity distinct from that in adults. We are aware that different nonstandardized methodologies with different substrate (human or animal) for evaluating antipituitary antibodies may give non-comparable results. Nevertheless, no temporal relationship between the times of examination and pituitary antibody results were found. In a few patients, including the positive girl, antipituitary antibodies remained negative several years after the first evaluation. Thus, pituitary hypoplasia in our patients seems unlikely to be secondary to an autoimmune process as observed in adults, indicating that its aetiology is different in children. This suggests that at least in the first two decades screening for antipituitary antibodies is not necessary in the presence of hormonal deficiency and pituitary abnormalities. The discrepancies in the conclusions drawn by Komatsu et al. (1988) and Mau et al. (1993) could result from the differences of sex and age as well as of race of the patients studied. Indeed, autoimmune processes (or autoantibodies) are more frequent in females and in the elderly. While the patients of Komatsu et al. (1988) were mostly women (82%) and older (73Y0 > 50 years), those of Mau et al. (1993) were prevalently males (83%) and younger (50% c50 years), probably explaining the low frequency of APHA observed by the latter in ESS. normal karyotype, normal pituitary gland morphology and IGHD, and remain so 2 years after the first evaluation; the significance of this is still to be clarified. They were negative in all i.he others as well as in 20 normal controls. Bottazzo et al. (1980) described a girl with Turner’s syndrome, GH deficiency and GH cell antibodies in which no radiological Mohamad Maghnie Renata Lorini Francesca Severi Department of Pediatrics, IRCCS Policlinico S. Matteo, University of Pavia, Pavia. Italy