| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
*
Institut National de la Santé et de la Recherche Médicale (INSERM), Unit 430 and Université Pierre et Marie Curie, Hôpital Broussais, Paris, France;
Research Institute of Hematology, Moscow, Russia;
Immunology Unit, Vall d’Hebron, Barcelona, Spain;
§
Department of Pediatrics, Soroka Medical Center, Beer Sheva, Israel;
¶
Department of Pediatrics, University of Brescia, Brescia, Italy;
||
Institute of Immunology, University of Vienna, Vienna, Austria;
#
INSERM, Unit 429, Hôpital des Enfants-Malades, Paris, France; and
**
Department of Pediatrics, University of Washington Medical School, Seattle, WA 98195
 |
Abstract |
|---|
 Top Abstract IntroductionPatients and MethodsResultsDiscussionReferences |
|---|
|
Introduction |
|---|
|
TopAbstractIntroductionPatients and MethodsResultsDiscussionReferences |
|---|
Natural Abs of the IgM, IgG, and IgA isotypes that are reactive with a broad range of self Ags are present in normal serum (24, 25, 26). Ab repertoires of natural IgM and IgG toward self Ags are highly homogeneous among healthy individuals and remain invariant with aging (27, 28, 29, 30). Evidence obtained in mice suggests that the selection of autoreactive B cells requires the presence of CD4+ T lymphocytes under conditions of both pathological and physiological autoimmunity (31, 32, 33, 34).
In the present study, we analyzed the Ab repertoires of IgM and IgG in the serum of patients with HIM by means of a quantitative immunoblotting technique that allows for multiparametric statistical analysis of Ab reactivities with self and nonself Ags. We demonstrate that Ab repertoires of IgM toward self Ags are skewed in patients with HIM, whereas repertoires directed toward bacterial Ags do not differ between patients and healthy controls. In addition, little reactivity with self Ags of IgG in the serum of patients with HIM was detected. Our observations demonstrate that the lack of functional CD40-CD40L interactions and/or impaired T/B cell cooperation in HIM affect the selection processes of natural self-reactive B cell repertoires.
|
Patients and Methods |
|---|
|
TopAbstractIntroductionPatients and MethodsResultsDiscussionReferences |
|---|
EDTA-plasma was obtained from 19 children (18 boys and 1 girl), between 3 and 14 years old, diagnosed with immunodeficiency with HIM. Twenty healthy young adult male blood donors with a mean age of 34 ± 5 years were used as normal controls. Previous studies from our laboratory had demonstrated that self-reactive Ab repertoires in serum remain highly homogeneous and invariant from early childhood to adulthood (29, 35).
Sixteen of the male patients had X-HIM. Two male patients presented with autosomal recessive HIM, and one female patient had secondary HIM associated with congenital rubella. Activated PBMC totally lacked expression of the CD40L Ag in 11 X-HIM patients, whereas expression of the Ag was low in 3 patients (2 patients with X-HIM and 1 patient with autosomal recessive HIM) and unknown in the remaining 5 cases. All patients had suffered from severe and/or recurrent infections before diagnosis, including upper respiratory tract infections (10 of 16), P. carinii pneumonia (2 of 16), and episodic or chronic infectious diarrhea (6 of 16 including Cryptosporidium infection in 3 cases). Hematological abnormalities included neutropenia in 11 patients and pure RBC aplasia in 2 patients due to parvovirus B19 infection, as previously reported (36). Nephritis was present in 1 patient and arthritis in 2 patients (described in 1). Autosomal recessive HIM was diagnosed in 2 patients with low or normal expression of the CD40L Ag, respectively, and suffering from upper respiratory tract infections. One patient had secondary HIM associated with congenital rubella. CD40L expression in this patient was normal, and the patient suffered upper respiratory tract infections. Twelve of the 19 patients received substitutive therapy with i.v. Ig, in amounts ranging from 200 mg/kg/body weight every 5 wk to 600 mg/kg every 2 wk. Seven of the 19 patients had not been treated with i.v. Ig at the time of serum sampling.
The mean serum IgM concentration in HIM patients was 3.8 ± 3.5 mg/ml (mean ± SD, ranging from 0.4 to 14) at the time of diagnosis, as determined by nephelometry. At the time of sampling, the mean IgM and IgG concentrations were 2.2 ± 2.2 and 0.7 ± 0.4 mg/ml, respectively, in the serum of the 7 patients who were not substituted with i.v. Ig. These concentrations were 2.3 ± 2.1 and 2.6 ± 2.1, respectively, in the serum of the 12 i.v. Ig-treated patients. The concentrations of serum IgM and IgG in healthy controls were 1.4 ± 0.5 and 11.8 ± 3.1 mg/ml, respectively. Sandoglobulin (a gift of the Central Laboratory of the Swiss Red Cross, Bern, Switzerland) was used as a standard for normal IgG. A reference preparation of normal IgM (i.v. IgM) was obtained by submitting Pentaglobin (Biotest Pharma, Dreieich, Germany), an IgM-enriched therapeutic preparation of pooled normal human IgG, to size exclusion chromatography on Sephacryl HR S-300 (Pharmacia, Uppsala, Sweden).
Analysis of Ab repertoires by quantitative immunoblotting
For the study of Ab repertoires, we have used a quantitative
immunoblotting technique that allows the simultaneous assessment of
reactivities of different sources of Abs with a large number of Ags in
total tissue extracts (28, 37). The method has been described in detail
elsewhere (27, 28). Extracts of histologically normal human kidney,
lung, liver, and stomach were used as sources of self Ags. Sources of
bacterial Ags were extracts of the commensal and pathogenic bacteria
P. aeruginosa (Collection de l’Institut Pasteur, CIP A22)
and Staphylococcus epidermidis (CIP 8155). Proteins were
extracted from tissues and bacteria in 2.0% SDS, 1.45 M 2-ME, 125 mM
Tris-HCl (pH 6.8), containing 1.0 µg/ml aprotinin, 1.0
µg/ml pepstatin, and 1.0 mM EDTA on ice. Samples were sonicated 4
times for 30 s to disrupt DNA and boiled for 5 min. Protein
concentrations were determined by means of a Folin assay. The amount of
tissue proteins subjected to electrophoresis and transfer ranged
between 100 and 600 µg/gel, depending on the tissue extract, and was
maintained constant for a given tissue in all experiments. Low amounts
of carbohydrates could be detected in solubilized protein samples.
Proteins were subjected to preparative SDS-PAGE in 10% polyacrylamide
and transferred onto nitrocellulose (Schleicher & Schuell, Dassel,
Germany) for 60 min at 0.8 mA/cm2 using a SemiDry
Electroblotter A (Ancos, Denmark). Membranes were blocked with
PBS-Tween. The source of Abs to be tested was then incubated with the
membranes following the addition of one sample per slot in a Cassette
Miniblot System (Immunetics, Cambridge, MA) overnight at 4°C. The
membranes were washed and incubated with µ-chain-specific secondary
goat anti-human IgM Ab (Southern Biotechnology Associates,
Birmingham, AL) or secondary goat anti-human Fc
Ab coupled to
alkaline phosphatase (Sigma, St. Louis, MO). Immunoreactivities were
revealed using the nitroblue tetrazolium/bromochloroindolyl phosphate
substrate (Promega, Madison, WI). The dependency on variable regions of
the recognition of blotted Ags by IgM and IgG has been documented
previously (27, 28). Quantitation of immunoreactivities was performed
by densitometry in reflective mode using a high resolution CCD camera
system (Masterscan, Scanalytics, Billerica, MA). Blotted proteins were
then stained using colloidal gold (Protogold) (Biocell, Cardiff, U.K.)
and subjected to a second densitometric analysis to score the protein
profile and to quantitate transferred proteins. Data were analyzed
using a Quadra 650 computer (Apple Computer, Cupertino, CA) and IGOR
software (Wavemetrics, Lake Oswego, OR). Densitometric profiles of
immunoreactivity were compared by referring to their corresponding
protein profile, following correction of the migration defects by
superimposition of protein peaks. A sample of the reference IgM or IgG
preparations was included in each blot, to rescale the different
membranes transferred with a given protein extract and to adjust for
the intensity of staining of different membranes.
Analysis of the densitometric profiles obtained with serial dilutions of i.v. Ig demonstrated a dose-dependent decrease in the area under the curve corresponding to peaks of reactivity for concentrations of IgG between 50 and 400 µg/ml and of IgM between 5 and 50 µg/ml. Saturation was achieved for concentrations of IgG and IgM above 400 and 50 µg/ml, respectively. The reproducibility of the assay was 10% (variation coefficient). The 95% confidence interval of the mean area under the curve corresponding to each peak of immunoreactivity was 30% in the case of IgM and 25% in the case of IgG, as calculated by Student’s t test (27, 28).
Statistical analysis
Densitometric profiles of immunoblots were divided into sections corresponding to individual peaks of immunoreactivity. Respective peak areas were calculated in the case of each tissue extract. To discriminate between individual repertoires, peak areas corresponding to sections obtained with all self Ags were submitted simultaneously to principal component analysis (PCA) (38), using Mathematica (Wolfram Research, Champaign, IL) software. The repertoire of reactivities of each individual in a given sample was represented as a single symbol in a two-dimensional linear subspace. Discrimination between repertoires was assessed by submitting PCA data to linear discriminant analysis (LDA) and by subsequently comparing factors 1 of the LDA by Mann-Whitney U test. The statistical comparison required that factor 1 of the LDA accounted for >70% of the variance of the data. PCA of repertoires of Ab reactivities performed individually for each group of individuals further allowed the calculation of respective variances. Variances were compared by F test. We also quantitated total immunoreactivities of serum IgM with each source of Ags by computing the total area under the curves of the respective densitometric profiles. Mean values of total reactivities obtained with each source of Ag were compared between groups of individuals in a global analysis by Fisher’s test.
Analysis of IgM reactivity by ELISA
Ninety-six-well ELISA plates (Nunc, Roskilde, Denmark) were coated with human Ag H (a gift from Prof. J.-P. Cartron, Institut National de la Santé et de la Recherche Médicale (INSERM), Unit 76, Paris, France), human laminin (Sigma), human thyroglobulin (Biogenesis, Poole, U.K.), human transferrin (Sigma), calf actin, and calf thymus DNA (Sigma) at 10 µg/ml in PBS, pH 7.4, and with human low density lipoprotein (LDL, a gift from J. Chevalier, INSERM, Unit 430, Paris, France) at 10 µg/ml in PBS, 2.7 mM EDTA, and 20 µM butylated hydroxytoluene (Sigma) overnight at 4°C. Plates coated with DNA had been pretreated with 10 µg/ml poly-L-lysine (Sigma). Plates were saturated with 1.0% BSA (Sigma) in PBS for 30 min at 37°C. After a washing with PBS, the plates were incubated with decreasing concentrations of serum IgM to be tested for 1 h at 37°C before extensive washing with PBS and addition of goat anti-human IgM Abs coupled to alkaline phosphatase (Southern Biotechnology Associates). The background reactivity of serum IgM scored with nonsensitized plates, or with poly-L-lysine-treated plates in the case of DNA, was subtracted from the reactivity of IgM with the respective Ags. The mean values of the corrected IgM reactivities were compared between groups for each Ag by means of an one-sided Student t test.
|
Results |
|---|
|
TopAbstractIntroductionPatients and MethodsResultsDiscussionReferences |
|---|
The reactivity with self Ags of IgM in the serum of healthy blood
donors and patients with HIM was analyzed by immunoblotting using
extracts of normal homologous human kidney, lung, liver, and stomach as
sources of self Ags. From 20 to 30 major peaks of reactivity were
scored after blotting of IgM of healthy individuals with Ags in the
extracts (Fig. 1
and data not shown). As
previously reported (28, 35), the densitometric profiles of reactivity
of IgM of healthy donors exhibited a strong homogeneity between
individuals with regard to the nature of the protein bands recognized
in all tissue extracts that were tested. From 15 to 20 major peaks of
reactivity were also detected after blotting of IgM of patients with
HIM with self Ags (Fig. 1 and data not shown). The densitometric
profiles of IgM reactivities exhibited a strong homogeneity between
patients with regard to the nature of the protein bands recognized and
were also homogeneous with regard to the intensity of
immunoreactivities in lung and stomach Ags, but not in kidney and liver
Ags (Fig. 1 and data not shown).
|
). Most of the protein bands
detected by IgM in the serum of healthy donors were also recognized by
HIM IgM with lower intensity. Several of the IgM reactivities expressed
by healthy subjects were not present in the repertoire of reactivities
of IgM of HIM patients. The overall reactivity with self Ags of IgM of
the HIM patients, as calculated by computing the mean area under the
curve of the densitometric profiles obtained with each tissue extract,
was significantly lower than that of healthy individuals in kidney,
liver, and stomach Ags, but not in lung Ags (Table I).
|
|
). The data obtained by PCA were then submitted
to LDA. Factors 1 of LDA were then compared by means of the
Mann-Whitney U test. PCA discriminated between repertoires
of Ab reactivities with self Ags of healthy donors and patients with
HIM (p < 0.001 in the case of all tissue
extracts). PCA did not discriminate between self-reactive repertoires
of HIM patients undergoing substitutive therapy with i.v. Ig and
untreated patients (data not shown), indicating that the administration
of normal IgG to HIM patients does not restore a physiological pattern
of self-reactivity of IgM. PCA did not discriminate between
self-reactive IgM Ab repertoires of patients with X-HIM and the
patients with autosomal recessive HIM (data not shown). We then
assessed the relative homogeneity of Ab repertoires of the 19 patients
and 20 controls, by calculating the individual variances of the
repertoires of self-reactivities in the case of each protein extract,
by means of PCA. The variances did not differ significantly between
healthy donors and HIM patients (Table II), demonstrating that self-reactive
repertoires of IgM were homogeneous in both groups of individuals.
Taken together, these data document that self-reactive repertoires of
IgM of patients with HIM differ significantly from those of healthy
donors.
|
). The reactivity of IgM from
patients with HIM was, however, identical with that of healthy subjects
in the case of Ag H and LDL (Fig. 3), suggesting that the nature of the
autoantigen determines whether T cell help is required for the
selection of autoreactive B cell clones.
|
To investigate Ab repertoires against nonself Ags, we assessed the
reactivity of IgM of patients with HIM with extracts of P.
aeruginosa and S. epidermidis. The densitometric
profiles of reactivity of IgM of healthy donors and HIM patients
exhibited between 10 and 20 and between 5 and 10 major peaks of
reactivity with the 2 sources of bacterial Ags, respectively (data not
shown). The densitometric profiles of IgM of healthy donors exhibited a
strong homogeneity between individuals with regard to the nature of the
protein bands recognized and the intensity of the peaks, whereas
densitometric profiles of IgM of patients were homogeneous in the case
of P. aeruginosa extracts and heterogeneous in that of
extracts of S. epidermidis (data not shown). The total
reactivity of IgM of HIM patients with the bacterial extracts did not
differ significantly from that of healthy individuals (Table III). We then computed the areas of the
peaks of immunoreactivity in the densitometric profiles to allow for
multiparametric analysis of the data. The data obtained in healthy
donors and patients were compared by means of PCA within a 46- to
58-dimension vector space, depending on the bacterial extract, and
fitted into the 2-dimensional linear subspace that accounted for 69.5
to 70.3% of the variance and allowed for the most powerful
discrimination between individuals. PCA did not discriminate between
repertoires of reactivities with bacterial Ags of patients and healthy
donors (Fig. 4). PCA also did not
discriminate between autoantibody repertoires of patients with X-HIM
and patients with autosomal recessive HIM (data not shown). When
calculating the individual variances of repertoires of reactivity of
IgM with bacterial Ags by PCA (Table IV),
variances of repertoires of healthy donors were found not to differ
significantly from those of repertoires of HIM patients, indicating
that the relative homogeneity of the repertoires of reactivities of IgM
to external Ags was similar in the two groups of individuals. Thus,
patients with HIM appeared to generate an IgM Ab repertoire to
commensal bacteria similar to that of healthy individuals, contrasting
with impaired Ab repertoires to self Ags.
|
|
|
We analyzed the repertoires of reactivity of IgG in the serum of 7
patients who had not been substituted with i.v. Ig and of 5 control
healthy subjects. The concentration of IgG in patients’ serum was
<0.4 mg/ml in 3 patients and ranged between 0.6 and 1.2 mg/ml in the 4
remaining patients. Reactivities of IgG were tested in serum diluted to
achieve a final IgG concentration of 200 µg/ml. IgG of healthy donors
strongly reacted with 20–30 protein bands, depending on the tissue
extract (data not shown). As previously described (27), the patterns of
reactivities were heterogeneous among healthy individuals with regard
to both the nature of the protein bands recognized and the intensity of
reactivities. No reactivity with self Ags and nonself Ags was seen with
serum of the 3 patients who exhibited the lowest concentrations of
serum IgG. IgG of the remaining 4 HIM patients exhibited weak
reactivity with 10 to 15 protein bands in the kidney extract (data not
shown). In contrast, a strong reactivity was observed with Ags in the
S. epidermidis extract (data not shown). The total
reactivity of IgG of HIM patients was significantly lower than that of
healthy blood donors in the case of kidney Ags
(p < 0.001), but not in that of S.
epidermidis Ags (p = 0.66) (Fig. 5 and Table V), indicating a selective bias in the
repertoire of reactivities of IgG toward self Ags.
|
|
). Individual
variances of the repertoires of reactivity of IgG with both kidney and
S. epidermidis Ags, calculated by PCA, differed
significantly between healthy donors and patients (Table VI), indicating a higher degree of
heterogeneity of the repertoires of reactivity of IgG in healthy
subjects than in HIM patients.
|
|
Discussion |
|---|
|
TopAbstractIntroductionPatients and MethodsResultsDiscussionReferences |
|---|
Natural autoreactive IgM and IgG Abs are found in the serum of healthy individuals (24, 39). The normal repertoire of Ab reactivities with self Ags is homogeneous between individuals and restricted to a limited set of immunodominant Ags that is conserved among healthy individuals and stable throughout life (27, 28, 29, 35). Repertoires of serum IgM and IgG remain invariant in children and young adults and between males and females with regard to reactivity with self Ags (29, 35, 40). Significant alterations in self-reactive Ab repertoires have been observed in autoimmune conditions, such as myasthenia gravis and systemic lupus erythematosus (41, 42).
Here we investigated Ab repertoires in the serum of 19 patients with HIM, 16 of whom had X-HIM. We observed that the densitometric patterns of reactivity with self Ags of IgM in the serum of patients with HIM were homogeneous among the patients but differed significantly from those of healthy donors. Several peaks of self-reactivity of IgM in normal serum were lacking in the serum of HIM patients. Principal component analysis discriminated between self-reactive IgM repertoires of patients and healthy donors. The variances of individual Ab repertoires were of a similar order of magnitude in both groups, indicating that healthy donors and patients with HIM represent homogenous groups of individuals characterized by distinct patterns of recognition of self Ags. These observations emphasize the key role of T lymphocytes for establishing natural self-reactive repertoires of IgM Abs, as suggested by previous studies in mice. Thus, it has been shown that euthymic and athymic (nu/nu) BALB/c mice present with distinct self-reactive repertoires of IgM (34). The transfer of syngeneic T cells to athymic mice restored high frequencies of autoreactive precursor B cell clones (33) and altered repertoires of reactivities of natural autoantibodies, with patterns almost identical with those of euthymic mice (34). The transfer of syngeneic T cells to nude mice was also shown to restore normal titers of serum IgG (33, 34).
A number of studies document a role for IgG in the selection of IgM repertoires. Thus, maternal IgG decreases the concentration and alters the pattern of reactivity of serum IgM in newborn mice (34, 43). Treatment with i.v. IgG of autoimmune patients, is followed by altered titers of specific IgM and IgG autoantibodies (44, 45, 46). In patients with HIM, the administration of i.v. Ig often results in a dramatic and long-lasting decrease of serum IgM levels (21, 23, 47, 48, 49). The latter decrease may reflect the effects of i.v. Ig on B cell repertoires or, alternatively, be a consequence of a better control of recurrent infections. In our study, however, no difference in the serum concentration of IgM was observed between patients substituted with i.v. Ig and untreated patients (1). In addition, PCA did not discriminate between self-reactive Ab repertoires of IgM of i.v. Ig-treated and untreated HIM patients. Since the concentration of IgG in the serum of the 12 patients treated with i.v. Ig was significantly lower than that in the serum of healthy individuals (2.6 ± 2.1 mg/ml), the possibility remains that IgG was at too low a concentration in plasma to efficiently influence the selection of B cell repertoires. Thus, it is unclear at present whether alterations in the self-reactive repertoires of IgM in patients with HIM are strictly dependent on defective T cell/B cell signaling or whether these alterations are also a consequence of decreased levels of autologous IgG.
Increased concentrations of IgM in the serum of patients with HIM were
not associated with an increase in the overall reactivity of IgM with
self Ags. In fact, the total autoreactivity of IgM of patients was
significantly lower than that of controls in the case of three of the
four tissue extracts that we tested as sources for self Ags. Our
results agree with a previous report on HIM patients who were devoid of
anti-Gal
1–3Gal Abs as compared with healthy individuals (50).
However, in our study, the bias in IgM autoreactivity was restricted to
protein Ags, suggesting that the role of T cell help in the selection
of self-reactive B cell clones depends on the nature of the
autoantigens. It may be speculated that autoimmune manifestations which
were reported to occur in patients with HIM (2, 19) may be dependent on
an impaired control of autoreactivity, secondary to defective T cell-B
cell interactions. Increased titers of IgM in patients with HIM have
been suggested to reflect a compensatory mechanism in individuals
confronted with chronic stimulation of the immune system by infectious
agents (1, 2). If that were the case, one would have expected a bias in
the repertoire of reactivities of IgM toward bacterial Ags. However, we
did not observe qualitative or quantitative differences in the
repertoires of IgM toward Ags of P. aeruginosa and S.
epidermidis. These observations suggest that IgM immune responses
against foreign Ags similar to those of healthy individuals may occur
in the absence of normal autologous T cells. In this respect, it is
noteworthy that a proportion of B cells in patients with X-HIM may be
induced to undergo somatic mutation (12).
There was almost no reactivity toward self Ags of IgG in the serum of the seven untreated patients with X-HIM whom we tested. In contrast, when tested at a similar concentration, IgG in the serum of healthy individuals reacted with several protein Ags in homologous tissue extracts. The lack of self reactivity of IgG in HIM serum may be a consequence of defective signaling through CD40 and CD40L, suggesting the requirement for normal T and B cell interactions for the generation of natural autoantibodies of the IgG isotype. An alternative hypothesis is that IgG autoantibodies are produced in HIM but that IgG autoreactivity is masked in serum by autologous IgM, as previously shown in normal serum (51, 52).
Taken together, our observations emphasize the key role of T lymphocytes in establishing natural self-reactive Ab repertoires.
|
Acknowledgments |
|---|
|
Footnotes |
|---|
2 Address correspondence and reprint requests to Dr. Michel D. Kazatchkine, INSERM U430, Hôpital Broussais, 96, rue Didot, 75014 Paris, France.
3 Abbreviations used in this paper: HIM, hyper-IgM syndrome; X-HIM, X-linked HIM; CD40L, CD40 ligand; PCA, principal component analysis; LDA, linear discriminant analysis; LDL, low density lipoprotein.
Received for publication September 30, 1998. Accepted for publication February 12, 1999.
|
References |
|---|
|
TopAbstractIntroductionPatients and MethodsResultsDiscussionReferences |
|---|
and immunoglobulin polypeptide chains. Am. J. Med. 39:319.
1 A (ß2A) globulins and 2 (G) globulins. Pediatrics 32:407.This article has been cited by other articles:
|
|
 |
|
  H Zephir, D Lefranc, S Dubucquoi, J de Seze, L Boron, L Prin, and P Vermersch Serum IgG repertoire in clinically isolated syndrome predicts multiple sclerosis Multiple Sclerosis, May 1, 2009; 15(5): 593 - 600. [Abstract] [PDF]
|
|
|
|
 |
|
 M. Herve, I. Isnardi, Y.-s. Ng, J. B. Bussel, H. D. Ochs, C. Cunningham-Rundles, and E. Meffre CD40 ligand and MHC class II expression are essential for human peripheral B cell tolerance J. Exp. Med., July 9, 2007; 204(7): 1583 - 1593. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Lefranc, L. Almeras, S. Dubucquoi, J. de Seze, P. Vermersch, and L. Prin Distortion of the Self-Reactive IgG Antibody Repertoire in Multiple Sclerosis as a New Diagnostic Tool J. Immunol., January 1, 2004; 172(1): 669 - 678. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. D. Arkwright, M. Abinun, and A. J. Cant Autoimmunity in human primary immunodeficiency diseases Blood, April 15, 2002; 99(8): 2694 - 2702. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M.-J. Jacobin, J. Laroche-Traineau, M. Little, A. Keller, K. Peter, M. Welschof, A. Nurden, and G. Clofent-Sanchez Human IgG Monoclonal Anti-{alpha}IIb{beta}3-Binding Fragments Derived from Immunized Donors Using Phage Display J. Immunol., February 15, 2002; 168(4): 2035 - 2045. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Martinez-Barnetche, V. Madrid-Marina, R. A. Flavell, and J. Moreno Does CD40 Ligation Induce B Cell Negative Selection? J. Immunol., February 1, 2002; 168(3): 1042 - 1049. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Stahl, S. Lacroix-Desmazes, D. Heudes, L. Mouthon, S. V. Kaveri, and M. D. Kazatchkine Altered control of self-reactive IgG by autologous IgM in patients with warm autoimmune hemolytic anemia Blood, January 1, 2000; 95(1): 328 - 335. [Abstract] [Full Text] [PDF]
|
|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
). For each donor, the densitometric profile of reactivity with a
given tissue extract was divided into sections corresponding to peaks
of reactivity so as to calculate the height of each peak. The data were
subjected to PCA within a 31- to 56-dimension vector space, depending
on the tissue extract, and fitted within two-dimensional linear
subspaces (factors 1 and 2). Percentages of variance accounted for by
factors 1 and 2 are indicated on the abscissa and ordinate,
respectively. Each symbol represents the reactivity of IgM of a single
individual. In both liver and stomach extracts, PCA discriminated
between repertoires of patients and controls (p <
0.001 by the Mann-Whitney test).
) and of 12 patients
with HIM (
