Female obesity is negatively associated with live birth rate following IVF: a systematic review and meta-analysis

BACKGROUND

A worldwide increase in the prevalence of obesity has been observed in the past three decades, particularly in women of reproductive age. Female obesity has been clearly associated with impaired spontaneous fertility, as well as adverse pregnancy outcomes. Increasing evidence in the literature shows that obesity also contributes to adverse clinical outcomes following in vitro fertilization (IVF) procedures. However, the heterogeneity of the available studies in terms of populations, group definition and outcomes prevents drawing firm conclusions. A previous meta-analysis published in 2011 identified a marginal but significant negative effect of increased female body mass index (BMI) on IVF results, but numerous studies have been published since then, including large cohort studies from national registries, highlighting the need for an updated review and meta-analysis.

OBJECTIVE AND RATIONALE

Our systematic review and meta-analysis of the available literature aims to evaluate the association of female obesity with the probability of live birth following IVF. Subgroup analyses according to ovulatory status, oocyte origin, fresh or frozen-embryo transfer and cycle rank were performed.

SEARCH METHODS

A systematic review was performed using the following key words: ('obesity', 'body mass index', 'live birth', 'IVF', 'ICSI'). Searches were conducted in MEDLINE, EMBASE, Cochrane Library, Eudract and clinicaltrial.gov from 01 January 2007 to 30 November 2017. Study selection was based on title and abstract. Full texts of potentially relevant articles were retrieved and assessed for inclusion by two reviewers. Subsequently, quality was assessed using the Newcastle-Ottawa Quality Assessment Scales for patient selection, comparability and assessment of outcomes. Two independent reviewers carried out study selection and data extraction according to Cochrane methods. Random-effect meta-analysis was performed using Review Manager software on all data (overall analysis), followed by subgroup analyses.

OUTCOMES

A total of 21 studies were included in the meta-analysis. A decreased probability of live birth following IVF was observed in obese (BMI ≥ 30 kg/m2) women when compared with normal weight (BMI 18.5-24.9 kg/m2) women: risk ratio (RR) (95% CI) 0.85 (0.82-0.87). Subgroups analyses demonstrated that prognosis was poorer when obesity was associated with polycystic ovary syndrome, while the oocyte origin (donor or non-donor) did not modify the overall interpretation.

WIDER IMPLICATIONS

Our meta-analysis clearly demonstrates that female obesity negatively and significantly impacts live birth rates following IVF. Whether weight loss can reverse this deleterious effect through lifestyle modifications or bariatric surgery should be further evaluated.

Cosecretion of glycosylated prolactin and non-glycosylated prolactin from childhood to the end of puberty

BACKGROUND

Glycosylated prolactin (G-PRL) is considered as the major post-translational modification of prolactin (PRL) showing reduced lactotropic and mitogenic activities compared to non-glycosylated prolactin (NG-PRL).

AIM

To evaluate the evolution of G-PRL in normoprolactinemic children and adolescents and to analyze possible variations in glycosylated/total prolactin (T-PRL) ratios.

METHODS

T-PRL, G-PRL and NG-PRL were evaluated in 111 healthy female and male children and adolescents (4.1-18 years), classified as group 1 (Tanner I), group 2 (Tanner II-III) and group 3 (Tanner IV-V). G-PRL and NG-PRL were identified by chromatography on concanavalin-A-Sepharose.

RESULTS

G-PRL/T-PRL (median-range): females, group 1: 0.59 (0.17-0.77), group 2: 0.56 (0.31-0.78), group 3: 0.60 (0.38-0.79); males, group 1: 0.64 (0.39-0.80), group 2: 0.61 (0.24-0.79), group 3: 0.62 (0.35-0.90); the p value is not significant among the different groups in both genders. G-PRL/T-PRL ratios do not change when comparing low (first quartile) versus high (third quartile) T-PRL levels in the different groups.

CONCLUSION

Our study would appear to support cosecretion of G-PRL and NG-PRL from childhood to the end of puberty. Such cosecretion would not be dependent on sex steroid levels. It is important to point out that puberty does not change the proportions of G-PRL and NG-PRL.

Fetal gastrointestinal MRI: all that glitters in T1 is not necessarily colon

BACKGROUND

It has been described that both the colon and distal ileum present with a physiological hypersignal on T1-weighted sequences during the second and third trimesters of pregnancy because of their protein-rich meconium content, it was unclear whether the normal characteristics that have been described on fetal MRI can be applied to gastrointestinal (GI) obstructions.

OBJECTIVE

To analyse the localisation value of T1 hypersignal within dilated bowel loops in fetuses with gastrointestinal tract obstruction.

MATERIALS AND METHODS

A retrospective 4-year multicentre study analysing cases of fetal GI obstruction in which MRI demonstrated T1 hypersignal content in the dilated loops. Data collected included gestational age (GA) at diagnosis, bowel appearance on US, CFTR gene mutations and amniotic levels of gastrointestinal enzymes. The suggested prenatal diagnosis was eventually compared to postnatal imaging and surgery.

RESULTS

Eleven patients were included. The median GA at US diagnosis was 23 weeks (range 13-32). In eight cases there was a single dilated loop, while several segments were affected in three. The median GA at MRI was 29 weeks (range 23-35). One case presented with cystic fibrosis mutations. Final prenatally suspected diagnoses were distal ileal atresia or colon in nine cases and proximal atresia in two. Postnatal findings were proximal jejunal atresia in nine cases and meconium ileus in two. In five cases the surgical findings demonstrated short bowel syndrome.

CONCLUSION

In cases of fetal occlusion, T1 hypersignal should not be considered as a sign of distal ileal or colonic occlusion. The obstruction may be proximal, implying a risk of small bowel syndrome, which requires adequate parental counselling.

Magnetic resonance imaging in the prenatal diagnosis of congenital diarrhea

OBJECTIVE

Congenital diarrhea is very rare, and postnatal diagnosis is often made once the condition has caused potentially lethal fluid loss and electrolyte disorders. Prenatal detection is important to improve the immediate neonatal prognosis. We aimed to describe the prenatal ultrasound and magnetic resonance (MRI) imaging findings in fetuses with congenital diarrhea.

METHODS

The study reports the pre- and postnatal findings in four fetuses that presented with generalized bowel dilatation and polyhydramnios. We analyzed the fetal ultrasound and MRI examinations jointly, then compared our provisional diagnosis with the amniotic fluid biochemistry and subsequently with the neonatal stool characteristics.

RESULTS

In each of the four cases an ultrasound examination between 22 and 30 weeks' gestation showed moderate generalized bowel dilatation and polyhydramnios suggesting intestinal obstruction. MRI examinations performed between 24 and 32 weeks' gestation confirmed that the dilatation was of gastrointestinal (GI) origin, with a signal indicating intraluminal water visible throughout the small bowel and colon. The expected hypersignal on T1-weighted sequences characteristic of physiological meconium was absent in the colon and rectum. This suggested that the meconium had been completely diluted and flushed out by the water content of the bowel. The constellation of MRI findings enabled a prenatal diagnosis of congenital diarrhea. The perinatal lab test findings revealed two cases of chloride diarrhea and two of sodium diarrhea.

CONCLUSION

Congenital diarrhea may be misdiagnosed as intestinal obstruction on prenatal ultrasound but has characteristic findings on prenatal MRI enabling accurate diagnosis; this is important for optimal neonatal management.

A new case of megalencephaly and perisylvian polymicrogyria with post-axial polydactyly and hydrocephalus: MPPH syndrome

We report a new case of megalencephaly and polymicrogyria with post-axial polydactyly and hydrocephalus (MPPH syndrome) in an 18-month-old girl. She was the first child of healthy non-consanguineous parents and measurements at birth were +3 standard deviations (S.D.) for weight, +2 S.D. for length and +4 S.D. for OFC. Ultrasound scan at 24 weeks of gestation (WG) showed mild ventriculomagaly with unique umbilical artery and dacryocystocele. Clinical examination at birth revealed macrosomia with macrocephaly, facial dysmorphism, post-axial polydactyly at the right hand and both feet, and axial hypotonia with hypertonic arms and legs. At 18 months of age, weight was +2 S.D., length was +2 S.D. and OFC was +4 S.D. She remained hypertonic, could not sit and had no hand use. Cerebral magnetic resonance imaging showed stable ventriculomegaly and polymicrogyria located on the frontal and perisylvian region with white matter hypersignal on T2-weighted images. There was no associated visceral malformation. Standard and high-resolution cytogenetic examination, telomeric FISH and array-CGH studies were normal. This case represents the sixth observation of MPPH syndrome as described by Mirzaa et al. in 2004. We provide further neurological follow-up since three out of five index patients were aged 6 months or less. We postulate that macrosomia at birth might be a major feature (five/six cases), with advanced bone age in the two/two investigated cases. White matter abnormalities might be an occasional feature of this syndrome (three/six cases), as well as dacryocystocele, if not coincidental (one/six case). The mode of inheritance of this syndrome remains unknown since there was no significant family history in all reported cases. The search for infracytogenetic chromosomal imbalance was unsuccessful.

A new osteochondrodysplasia with severe osteopenia, preaxial polydactyly, clefting and dysmorphic features resembling filamin-related disorders

BACKGROUND

We report a 19-week gestation female foetus with a new syndrome characterised by increased nuchal translucency and severe micromelia with campomelia evident from the early second trimester.

METHODS AND RESULTS

Cytogenetic studies performed on amniocytes revealed a normal female karyotype. Autopsy after termination of pregnancy showed facial dysmorphism, cleft palate, bowed, shortened limbs, hypoplasia of the preaxial elements in all four limbs with accompanying accessory ossification centres in the feet, and severe calvarial underossification. A diagnosis of otopalatodigital syndrome type 2, associated with mutations in FLNA, a gene encoding the cytoskeletal protein filamin A, was considered but discarded due to the severity of micromelia, early lethality, and the presence of generalised osteopenia instead of hyperostosis. The degree of undermodelling and campomelia was reminiscent of another group of conditions that include atelosteogenesis types 1 and 3, caused by mutations in FLNB. Sequencing analysis did not reveal any pathogenic mutation in the three paralogous filamin genes: FLNA, FLNB and FLNC.

CONCLUSION

Clinical, radiological and cytogenetic findings suggest that this phenotype is a new entity whose aetiopathogenesis may be functionally related to the filaminopathies.

Heterogeneity of circulating prolactin in the bitch

Different molecular forms of circulating prolactin (PRL) are known to occur in several species. As no such information was available in dogs, we assessed the molecular profile of circulating PRL in bitches. Pooled sera from covertly (CTRL) and overtly pseudopregnant (PSPT) diestrous bitches with high or low (> 10 or < 10 ng x mL(-1), respectively) serum PRL (measured by ELISA) were analyzed by Sephadex G-100 and Concanavalin A-Sepharose column chromatography. Four serum PRL fractions were identified and termed big-big, big (> 67 kDa), native (23 kDa) and fragmented (< 20) kDa) PRL. The percentages of these fractions were roughly similar in CTRL and PSPT animals, irrespective of their serum PRL levels (higher in PSPT than in CTRL bitches). A large proportion of glycosylated PRL (between 69 and 100%) was also detected in these sera. We conclude that in dogs, circulating PRL occurs in multiple molecular forms, whose relative abundance is comparable in covertly and overtly pseudopregnant bitches.

Recombinant human follicle-stimulating hormone administration increases testosterone production in men, possibly by a Sertoli cell-secreted nonsteroid factor

We previously showed that recombinant human FSH (R-FSH) in males increased the testosterone (T) concentration in spermatic venous blood (SB). To investigate the effect of R-FSH on spermatic steroid levels and the action of steroid- and LH-free SB on isolated Leydig cells, nine normospermic males were studied during spermatic cord surgery. Peripheral blood and SB samples were collected before and 30 min after iv administration of 150 U R-FSH to measure LH, FSH, T, estradiol, 17alpha-hydroxyprogesterone, and sex hormone-binding globulin, and in SB, androstenedione (delta4) and dehydroepiandrosterone (DHEA) were also measured. LH bioactivity was assessed by in vitro production of T in isolated Leydig cells. The actions of R-FSH and SB (steroid and LH free) were analyzed in the bioassay. Data are expressed as the mean +/- SE. FSH in peripheral blood and SB increased by 411% and 477% after R-FSH administration. R-FSH induced a significant increase in spermatic T (basal vs. 30 min, 326.4 +/- 98.5 vs. 732.4 +/- 152.8 ng/mL; P < 0.047) and in spermatic estradiol (289.5 +/- 66.9 vs. 535.6 +/- 83.4 pg/mL; P < 0.036). The T/delta4 ratio (36.9 +/- 9.2 vs. 74.5 +/- 13.3; P < 0.019) and the T/DHEA ratio (10.8 +/- 1.1 vs. 22.4 +/- 4.9; P < 0.024) increased significantly. In isolated Leydig cells, R-FSH did not change T production, but the SB (steroid and LH free) after R-FSH administration induced an increase in T production (3.3 +/- 0.6 vs. 4.9 +/- 0.6 ng/tube; P < 0.04). LH-like activity was found in a more than 50,000-Da fraction after centrifugation in Amicon filters, even in the presence of anti-LH. These results suggest that R-FSH increases the production of T by Leydig cells through a Sertoli cell-released nonsteroid factor with a molecular mass greater than 50 kDa. The increase in the T/delta4 and T/DHEA ratios indicates that this factor would act by amplifying the LH response through the delta5 pathway and the 17beta-hydroxysteroid dehydrogenase enzyme.

HLA typing with monoclonal antibodies: evaluation of 356 HLA monoclonal antibodies including 181 studied during the 10th International Histocompatibility Workshop

During the 10th International Histocompatibility Workshop (10th WS), 181 HLA MoAbs were studied using lymphocytotoxicity micro-technique (LCT) and/or enzyme immuno-assay (EIA), and their capacity to serve as typing reagents was evaluated. 129 MoAbs were tested by both techniques. Results obtained with 92 class I and 86 class II polymorphic MoAbs (10th WS) were compared to published data concerning 180 class I and 176 class II polymorphic MoAbs, listed in an HLA-MoAbs Register maintained in our laboratory. The following conclusions can be proposed: 1/HLA-A, B typing by LCT with MoAbs is possible for about 14 specificities. Some specificities are clearly recognized (HLA-A3, B8, B13, Bw4, Bw6), others are recognized as cross-reacting groups (B7+27+w22+40), others are not currently recognized by any MoAb with restricted specificity (B5, B15). Several MoAbs confirmed the existence of shared epitopes between products from a single locus (A2-A28, A25-A32), or from A and B loci (A2-B17, Bw4-A9-A32). A single HLA-Cw MoAb has been described. 2/HLA class II typing by LCT with MoAbs is more difficult than class I typing. DR2, DR3, DR4, DR5 and DR7 as well as DRw52 and DRw53 are well defined; other DR specificities are poorly or not at all defined. Particular associations (DR1+DR4, DR3+DRw6, all DR except DR7) are recognized by several MoAbs. All DQw specificities are well recognized, including new specificities defined only by MoAbs: WA (DQw4), TA10 (DQw7), 2B3 (DQw6+w8+w9). Only two HLA-DP MoAbs have been described. 3/Satisfactory results, similar to those of LCT, were obtained with EIA using lymphoid cell lines as targets. 4/Human MoAbs (12 in the Register) are satisfactory typing reagents. They could represent in the future a significant contribution to HLA typing with MoAbs.

Definition of a new supertypic HLA class II determinant (LAR) associated with HLA-DR2 and -DR7

A serum from a patient (LAR), immunized by pregnancies and blood transfusions, reacted with cells carrying HLA-DR2 and/or -DR7 specificities (titer 1:200-1:1000). Absorption-elution experiments showed that the allo-serum recognized a determinant shared by DR2 and DR7 cells. The high correlation coefficients (0.90-1) with these specificities suggested that the supertypic specificity LAR was carried by the first DR molecule encoded by DRB1 gene. LAR is another example of new supertypic specificities, reflecting structural homologies between alleles at HLA class II loci.

[Study of the HLA-DQ system by the complement fixation test on lymphocytes stimulated by phytohemagglutinin. Existence of HLA-DQX allele(s)]

The complement fixation microtechnique against PHA blasts has been used to study HLA-DQw1, 2, 3 specificities with sera from multiple transfused patients and/or from multiparous women. Several sera (6 or 7) have been used to define each DQ specificity. The sera have been chosen because of their reactivity with cells from HLA-DR 1, 2 or w6 donors (for DQw1), DR3 or 7 donors (for DQw2,) DR4 or 5 donors (for DQw3). Correlation coefficients between DQ and DR specificities were from 0.56 to 0.91. Correlation coefficients between sera were from 0.51 to 0.92 in each cluster of sera. The segregation of DQw1, 2, 3 specificities has been studied in 46 families with 234 children. This study showed haplotypes lacking DQw1, 2, 3 specificities. The segregation of such 11 DQX haplotypes has been observed in 38 children from 8 families; 5 children were DQX/DQX homozygotes. Up to now, no serological reagent defining the specificity (or specificities) corresponding to DQX has been found. No preferential association was observed between DQX and DR specificities. The gene frequencies observed in 170 haplotypes in these 46 families were as follows: DQw1: 0.400; DQw2: 0.252; DQw3: 0.282; DQX: 0.065. Detecting DQ specificities seems easier by CF on PHA blasts than by lymphocytotoxicity microtechnique against B lymphocytes and monocytes from pheripheral blood. This suggests that PHA blasts express larger quantities of DQ molecules than B lymphocytes and monocytes. The results confirm that complement fixation microtechnique against PHA blasts is efficient for HLA-DQw typing.

Evidence for a new HLA class II determinant present on cells from HLA-DR1 and/or -DR4 individuals

Evidence for a new HLA class II specificity is presented. It is recognized by LE serum, which reacts with most DR1 and/or DR4 individuals (r = 0.86). Its frequency in the French population is 0.33. Absorption-elution experiments showed that the serum reactivity was not due to a mixture of anti-DR1 and anti-DR4 antibodies, but to a single antibody population which could be absorbed on and eluted from both DR1(+) or DR4(+) cells. LE specificity seemed to be expressed on DR but not on DQ molecules since the serum reacted with and could be absorbed by DR+,DQw- cells; it did not react with a DR-,DQw+ mutant cell, but did react with the DR+,DQw+ parental cell. The relationship between LE specificity and MC1 and Te23 specificities remains to be determined.

Serological cross-reactivity between products of separate I regions

A B10.S(7R) anti-B10.S(9R) serum (anti-IJEkCd) contained, as expected, antibodies specific for the I-E-subregion-encoded determinant Ia.7. However, tests on recombinant haplotypes demonstrated a series of unexpected weak extrareactions which could be interpreted to be directed against antigenic determinants encoded in the I-A subregion of the H-2 complex. The same type of extrareaction was observed in eluates from I-As, I-Ek cells coated with A.TH anti-A.TL (I-As, I-Ek anti-I-Ak, I-Ek) serum. This reactivity in serum and eluates could be interpreted as cross-reactivity between products of the I-E and I-A subregions.

Inhibition of secondary mouse mixed lymphocyte reaction by anti-Ia sera

Secondary mixed lymphocyte reaction (MLR-II) was studied in A.TH anti A.TL and A.TL anti-A.TH combinations in which stimulation was mainly due to H-21-region differences. In both cases of MLR-II was specifically inhibited by the responder anti-stimulator Ia serum. The level of inhibition was dependent on the ratio of the amount of immune serum to the number of stimulating cells. The inhibitory activity and Ia antibodies were specifically absorbed and eluted together. The results confirm that the lymphocyte-activating determinants of the MLR-II (1) are carried by the Ia molecules and (2) are identical to the serologically defined Ia determinants. - Anti-Ia sera directed against private and public specificities of the stimulating cell induced a higher level of inhibition than anti-Ia sera directed only against public specificities, indicating that both private and public Ia specificities are involved in re-stimulation during MLR-II. - These results, in connection with others, suggest that the receptor of the proliferating T cell recognizes the same Ia determinant as the combining site of the Ia-recognizing antibody.

Binding of prolactin by fetal human lung cell membrane fractions

PRL binding capacity to cell membrane fraction was studied in lung tissues obtained from 4 human fetuses or newborn infants. One of the fetuses was a stillborn delivered at 33 weeks of gestation. The newborn infants died for unknown causes within 24 h after birth. The gestational age was 20, 39 and 41 weeks. The cell membrane fraction was prepared by ultracentrifugation. binding capacity and affinity constants were calculated according to athe Scatchard method. No significant specific binding of PRL to lung tissue from the stillborn fetus was observed, while for the other 3 newborn infants the binding capacity was 5.7, 7.4 and 9.6 fmol PRL bound/mg of membrane protein, respectively. The affinity constants were in the order of 10(10) M-1. these preliminary results show that human neonatal lung has receptors for PRL and suggest that PRL itself may be involved in the lung maturation.

Heterogeneous results of serum testosterone obtained in multiple blood samples from women with idiopathic hirsutism in both basal and post-dexamethasone conditions

Serum radioimmunoassayable testosterone (T), cortisol and luteinizing hormone (LH) were determined before and after dexamethasone (DXM) administration in 35 patients with idiopathic hirsutism (IH). Blood samples were taken at 15-min intervals during 1 hour in both basal and post-DXM conditions. Testosterone values obtained in 5 normal women in the same conditions during the early follicular phase were (mean +/- SD): baseline, 2.26 +/- 0.49 nmol/l; post-DXM, 0.80 +/- 0.35 nmol/l. Serum T levels in the whole group of patients with IH were significantly higher than those in the control group (mean +/- SD): baseline, 3.30 +/- 1.80nmol/l; post-DXM, 1.67 +/- 1.49nmol/l. Patients with IH were divided into 4 groups according to T results in the DXM test (mean +/- SD in both basal and post-DXM conditions, respectively): group 1 (n = 13) 1.67 +/- 0.66 and 0.62 +/- 0.35nmol/l; group 2 (n = 11) 3.89 +/- 1.63 and 3.09 +/- 1.49nmol/l; group 3 (n = 6) 3.96 +/- 1.46 and 0.87 +/- 0.73nmol/l; and group 4 (n = 5) 5.45 +/- 1.25 and 2.05 +/- 0.38nmol/l. In all cases, maximal adrenal inhibition, as judged by serum cortisol, was obtained. No LH modifications after DXM were obtained in any of the cases. Our results demonstrate that there is no common androgenic abnormality in IH. It is possible to obtain normal or high circulating T levels. The findings of this study also suggest that the adrenals, to ovary or both may be the sources of high T levels.

Prolactin, estriol and progesterone levels in frequent blood samples throughout normal pregnancy (lack of prolactin pulsatile secretion)

The aim of this paper was to study the episodic fluctuations of circulating prolactin (PRL), estriol (E3) and progesterone (P4) concentrations throughout pregnancy. We examined 24 pregnant women; 21 were between the 28th and 40th week of gestation, and the other 3 in the 12th, 16th and 20th week of gestation. Blood samples were drawn every 5 min for half an hour, and every 15 min for one and a half hour. Blood samples were taken in two and three different weeks of gestation in 11 and 2 of the cases, respectively. Two normal non-pregnant women were also studied and used as controls. PRL, E3 and P4 were determined by radioimmunoassay in all the samples. The coefficients of variation of PRL values were 40 and 22.6%, respectively, in the two control women, 8, 12 and 9.8% in the pregnant women studied at the 12th, 16th and 20th week of gestation, respectively, while in the 21 cases studied during the third trimester the coefficient of variation was 8 +/- 3% (mean +/- SD). The coefficients of variation of the values obtained for E3 and P4 in women studied in he third trimester were 26 +/- 15 and 16 +/- 6% (Mean +/- SD), respectively. There was an increase in the average concentration of the three hormones in all the cases at two or three different weeks. We can conclude that E3 and P4 have a pulsatile secretion pattern throughout pregnancy, and that PRL looses its pulsatile secretion as from an early gestational age. Our results suggested that central mechanisms regulating PRL episodic fluctuations were altered during pregnancy.

[Serological study of Ia antigens determined at the I-A and I-E sub-regions of the H-E complex in the H-2 complex of mice]

Immune serum B10.S (7R) anti-B10.S (9R)(anti I-JEkCd) contained as expected an anti-Ia7 antibody. A series of weaker but reproducible extra-reactions might recognize Ia3 specificity coded at the I-A subregion of the H-2 complex. Results with recombinant haplotypes confirmed this mapping. Such a reactivity could be interpreted as an interlocus cross-reaction (I-E/I-A) since the immunization was induced against an I-E subregion product. Another interpretation was possible: the immune serum would thus contain an antibody recognizing Ia7 (on the E alpha k Ia chain) and another antibody recognizing an antigenic determinant carried by the E beta k Ia chain. The latter antibody might recognize by cross-reaction as specificity carried by the A beta chain of various haplotypes (H-2b,k,q).

H-2 restriction for lymphocyte homing into lymph nodes

Migratory patterns into lymph nodes of labeled spleen lymphocytes, injected intravenously, showed considerable differences according to the genetic identity or disparity of donor and recipient mice. The use of mice carrying different H-2 haplotypes in the same B 10 background, or, conversely, the same H-2b haplotype in different backgrounds, showed that no homing was observed in the case of complete disparity at the H-2 complex, contrasting with optimal homing in the case of H-2 identity. Homing was not influenced by disparity at the genetic background. Irradiation of recipient mice did not change the results and suggested that no immunological host-vs.-graft reaction was involved in the H-2 restriction observed. The use of donor-recipient pairs carrying recombinant H-2 haplotypes showed that a single H-2 K and/or H-2 D identity allowed almost optimal homing. The results indirectly suggested that an immunological graft-vs.-host reaction was not involved in the phenomenon but rather a positive recognition of H-2 K or H-2 D identity between donor and recipient cells.

Reactivity of anti-HLA sera against mouse lymphocytes

The reactivity of anti-HLA hyper-immune sera was tested by the microlymphocytotoxicity technique (LCT) against a panel of mouse lymphocytes. Three levels of reactivity were observed: negative (immune sera titre 1:20 or less), weak (titre 1:40 to 1:80 with a percentage of dead cells less than 50%) or strong (titre 1:60 or more with 100% killing). Thirteen normal human sera were non-reactive. Eleven out of 60 hyper-immune sera were strongly reactive. Tests using congenic lines showed that the reactivity was controlled at the H-2 complex. One serum (CODRON) was studied in detail. When tested against a panel of strains carrying 10 different H-2 haplotypes, it reacted strongly against lymphocytes H-2d, ja, k, p and r; and did not react, or at least only weakly, against lymphocytes H-2b, f, q, s and v. Tests using mouse strains carrying the recombinant H-2 haplotypes h4, i5, i, y2, g, g2 and t1, suggested that the observed reactivity was directed against structures controlled at the K end of the H-2 complex (H-2.47?). Absorption-elution experiments with human and murine lymphocytes and platelets confirmed that the structures recognised by serum CODRON were determined at the major histocompatibility complex.

Separation of anti-Ia (I-region associated antigens) from anti-H-2 antibodies in complex sera, by absorption on blood platelets. description of three new Ia specificities

H-2 antigens are expressed in substantial amounts of murine blood platelets (for H-2 antigenic content 1 lymphocyte approximately 50 platelets) whereas Ia antigens are probably not expressed at all (minimal Ia antigenic content more than 35 times lower than for H-2). This property of blood platelets makes them very useful for the selective absorption of anti-H-2 antibodies from complex sera and for the preparation of specific anti-Ia antibodies from such sera. In 20 sera produced against the complete H-2 complex, 12 sera contained anti-Ia antibodies beside the expected anti-H-2 antibodies. In two sera, separation of the anti-Ia antibodies was easily obtained by absorption of the anti-H--2 antibodies on platelets. The analysis of one serum (C3H.Q X B10.D2) anti-C3H [(q X d) anti-k] showed that, in addition to be expected anti-H--2.23 and anti-Ia.2 antibodies, it contained at least three other Ia antibodies, separable by absorption on lymphocytes, which recognized three antigens--Ia.17, determined by the haplotypes k, f, s, r, j; Ia.18, determined by the haplotypes k, f, s; and Ia.19 determined by the haplotypes k and r. The genes are located in the I--A and/or I--B subregions of the H--2 complex.

A molecular defect in thrombasthenic platelets

An IgG antibody found in the serum of a thrombasthenic patient reacted in complement fixation with platelets from 350 normal individuals but was nonreactive with platelets from eight other thrombasthenic patients. ADP-induced aggregation of normal platelets was inhibited by the patient's antibody. Family studies using the quantitative complement fixation test showed that healthy heterozygotes were easily distinguishable from normal or thrombasthenic individuals since their platelets had an intermediate amount of the reactive antigen. Indirect immunoprecipitation tests using this serum and soluble membrane antigens labeled with iodine-125 that had been extracted from normal platelets by the detergent Nonidet P-40 gave a single radioactive peak at 120,000 mol wt in sodium dodecyl sulfate polyacrylamide gel electrophoresis. A similar estimate of the molecular weight was obtained from Sephadex G-200 filtration of the soluble antigens extracted from normal platelets by spontaneous release or chaotropic agents and tested in complement fixation with the patient's serum. These findings strongly suggest that the molecule recognized by this antibody is absent or structurally modified in thrombasthenia cases and that it may be involved in platelet aggregation.