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At least 19 recordsLinked to original sources
PubMed1991

Selective IgA deficiency, IgG subclass deficiency, and the major histocompatibility complex.

Here we have examined the connection between IgA deficiency, IgG subclass deficiency, and the absence of alleles of complement C4, and show that IgA deficient subjects who have IgG subclass deficiencies may also have an increased frequency of C4 null alleles. In our group, we found an increased incidence of HLA B38 which might reflect the ethnic composition of the patients tested. While family studies are of primary importance to assess the relationships between histocompatibility antigens and immune deficiency, these studies are complicated by the observation that C4 null alleles are not always inherited with the humoral defect.

Adult↗
PubMedDate not supplied

IgG subclass deficiency.

IgG subclasses have been recognized since the early 1960s. Four such subclasses, designated IgG1, IgG2, IgG3, and IgG4, are known to exist. Approximately 65 to 70% of the total circulating IgG in normal persons is of the IgG1 subclass. IgG2 constitutes 20 to 25% of circulating IgG, and IgG3 and IgG4 each represent less than 10%. Deficiencies in the various IgG subclasses have been detected in adults and children with common variable hypogammaglobulinemia as well as in those with relatively normal total IgG levels. An important issue facing clinicians today is to determine what, if any, therapeutic implications are associated with demonstration of an IgG subclass deficiency.

Humans↗
PubMed1991

IgG subclass deficiency with or without IgA deficiency.

IgG subclass deficiency (IgGSD) is difficult to define since reference materials vary between laboratories and the clinically relevant cut off levels for the various subclasses are not well known. The diagnosis of IgGSD should be based on more than one determination since the levels vary, due to various factors such as infections, operations, etc. There is a relation between IgGSD and occurrence of frequent infections, but at the same time even total lack of a subclass can be seen in healthy individuals. Infections in the upper and lower respiratory tract predominate. Gm allotypes influence IgG subclass levels. Most IgGSD patients are homozygous in the Gm system. Immunocytes producing IgG3 in the nasal mucosa correlate with serum IgG3 levels, whereas rectal IgG1 producing cells relate to serum IgG1 levels. This may reflect differences in antigen and/or mitogen exposure at the two mucosal sites. IgG2SD is the predominant form of IgGSD among children, whereas after puberty IgG3SD is most common. At the same age period there is a switch in sex distribution from three boys/one girl to one male/three females. Various abnormalities in B and T lymphocyte numbers and function are often found. In a double blind crossover study of Ig prophylaxis over 2 years in 43 IgGSD adult patients a significant decrease in the number of days with infections was seen both in the whole group and among the IgG1 deficient. Days with bronchial constriction were also significantly decreased among the 22 patients who had asthma as well. Acute bronchitis became significantly less frequent in the IgG3 deficient patients during Ig prophylaxis. This was seen in those under the lower range of 0.41 g/liter of Oxelius' early normal material, although many recent reference materials suggest 0.14-0.15 g/liter of IgG3 as the cut off. In a group of 25 consecutive patients with IgGSD + IgA deficiency recurrent respiratory infections were the major problem and lung function impairment was found in 12, and bronchiectasies in 5. Still many individuals with this combined deficiency have been reported to be healthy, again illustrating our limited understanding of these conditions.

Disease↗
PubMed1977

IgG deficiency in association with placental oedema.

Deficiency of the immunoglobulin C (IgG) in the human newborn is rare in the absence of maternal hypogammaglobulinaemia. Low concentrations of IgG in cord blood were found in 3 conditions--the donor twin in the fetofetal transfusion syndrome, hydrops fetalis and congenital hepatic disease. These were all associated with placental oedema. It is suggested that the oedema may be responsible for a disturbance in maternofetal placental transfer.

Dysgammaglobulinemia↗
PubMed1990

Selective IgG deficiency with a transcriptional disorder of the gamma switching region gene and the IL-4 gene.

A primary immunodeficiency patient was analysed whose serum IgG and IgE were extremely low but whose IgM and IgA levels were within the normal range or elevated. Southern blot analysis indicated no deletion of structural genes coding for C gamma, C epsilon, or C alpha. The majority of the patient's peripheral B cells expressed IgM and IgD on the surface yet IgG-positive B cells were not detected, suggesting that the defect is in a switch-recombination process from IgM to IgG. The RFLP pattern detected with the S mu and S gamma DNA regions revealed that there was no deletion or large mutation in the switch region DNA. An in vitro IgG production system with pokeweed mitogen showed an abnormality at the transcriptional level and the defects were in both the patient's T and B cells. Addition of recombinant IL-4 (rIL-4) to the normal B cells enhanced IgG production but the patient's B cells did not respond to rIL-4, although the IL-4 receptor was present at the normal level. Messenger RNA and IL-4 protein were not produced in the patient's T cells upon stimulation with phorbol ester and calcium ionophore, whereas IL-2 was normally produced. The patient's lymphocytes showed a proliferative response to various mitogens, including phorbol ester. The transcripts of unrearranged C gamma region genes were not detected in the patient's lymphocytes, suggesting that the chromatin structure of the S gamma region may not be open. These results suggest that the transcriptional defects at the S gamma region gene in B cells and at the IL-4 gene in the T cells may be responsible for the present IgG immunodeficiency. There might be a common transcriptional system operating in a certain step in the activation of both genes.

Adult↗
PubMed1992

The association of IgA deficiency but not IgG or IgM deficiency with a reduced patient and graft survival following liver transplantation.

Recipients of solid organ allografts require lifelong immunosuppression in order to prevent graft rejection and to maintain graft function. In general, such immunosuppression greatly impairs the cellular immune system, as this level of the immune system is principally responsible for self and non-self recognition. The consequences of allograft transplantation in terms of patient and graft survival when transplants are given to individuals who have a preexisting humoral immune deficiency characterized by a deficiency of the serum levels of one or more of the major Ig classes have not yet been reported. From February 1, 1981 through December 31, 1990, a total of 43 adult patients with a deficiency of 1 or more Ig classes received a ABO-matched liver allograft at this institution. This sample represents 2.5% of a total of 1684 adults transplanted during this interval. These 43 liver graft recipients could be divided into 3 major groups based upon the presence of an IgG, IgM, or IgA deficiency. IgG deficiencies were defined as levels less than 50 mg/dl. Patient and graft survival for the IgA-deficient group was significantly reduced (P less than 0.04 and P less than 0.009, respectively) compared with both the IgG- and IgM-deficient groups. The latter two groups did not differ from controls without an Ig deficiency for these same two endpoints. The major causes of death in the IgA-deficient group were sepsis and opportunistic infection. A third of the deaths in the IgA-deficient group occurred in the perioperative period (first 30 days) while greater than 50% of the deaths occurred within the first 3 months, and all deaths occurred before the first year. Based upon these data, the following conclusions can be made: (1) serum IgA deficiency but not IgG or IgM deficiency is associated with an increased post-OLTx death and graft loss rate; (2) the majority of these deaths are due to sepsis or an opportunistic infection; and (3) most of the deaths occur early. These data suggest that recognition of a deficiency of IgA prior to organ grafting necessitates meticulous attention to the prevention of infection in the immediate perioperative period if patient and graft survival of these patients is to be improved.

Adult↗
PubMed1990

IgG subclass deficiency.

Although the occurrence of selective deficiencies of serum IgG subclasses has been known for 20 years, the large body of data presently available was collected only recently owing to the use of performing monoclonal antibodies. IgG subclass deficiency is frequent, both as an apparently isolated defect (about one fourth of patients suffering otherwise unexplained repeated infections) and in association with a number of primary and required immunodeficiency states. This paper briefly reviews the methodological problems of serum IgG subclass measurement and data on subclass deficiency in a variety of clinical conditions.

Acquired Immunodeficiency Syndrome↗
PubMed1992

IgG subclass deficiency in children with recurrent bronchitis.

We studied the incidence of IgG subclass deficiency in children with recurrent bronchitis. Recurrent bronchitis was defined as three or more episodes a year during at least 2 consecutive years, of bronchopulmonary infection, productive cough with or without fever and/or diffuse râles by physical examination in the absence of asthma or atopy. Fifty three children were selected, of whom 30 (57%) were deficient in one of the IgG subclasses. None had an IgG1 deficiency. Nine (17%) were deficient in IgG2, 9 (17%) in IgG3 and 20 (38%) in IgG4. Isolated IgG subclass deficiencies were most frequently seen for IgG4 (14, 26%), less for IgG3 (6, 12%) and even less for IgG2 (4, 7%). Nine (17%) children were IgA deficient and 8 (15%) IgG deficient with a combined IgG subclass deficiency in 8 and 7 of them respectively. By subdivision into different age groups most patients were encountered in the youngest group. The mean content of IgG2, IgG3 and IgG4 in 3- to 4-year-old children with recurrent bronchitis was significantly lower than in the age matched controls. The mean value for IgG4 in the 5- to 6-year-olds was significantly lower than in the control group. This study demonstrates the correlation between recurrent bronchitis in childhood and IgG subclass deficiency. IgG subclass deficiency and recurrent bronchitis are both quite prominent phenomena in young children but rare in older children, suggesting a transient immaturity of the immune system as one of the possible pathogenetic factors. An IgA or an IgG deficiency is highly suggestive for the existence of a combined IgG subclass deficiency.

Bronchitis↗
PubMedDate not supplied

Evaluation and management of B and T cell abnormalities.

Congenital deficiencies that involve the lymphocyte system are complex and represent abnormalities in genetic control or gestational development. Only the more common prototypes of these diseases will be discussed. Diseases of the B cell system presented include X-linked agammaglobulinemia, selective IgA deficiency, IgG subclass deficiency, and common variable immunodeficiency. T cell defects discussed are Di-George syndrome and severe combined immunodeficiency. Also mentioned briefly are HIV infection and the increasing problem of AIDS. Diagnostic evaluation and general principles of treatment of these diseases are considered.

Agammaglobulinemia↗
PubMed1991

[Importance of studying deficiencies of IgG subclasses (IgG2 and IgG4) in immuno-allergologic practice].

Levels of the sub-classes of immunoglobulins IgG2 and IgG4 have been established by radial diffusion with monoclonal antibodies in 150 subjects. 49 (42 adults and 7 children) showed either a low level of IgG2 (less than 0.42 g/l n = 11) or a reduced level of IgG4 (less than 0.05 g/l n = 38). A single patient had a double deficit, 38 subjects had a superinfection of which 17 had a severe form and in 77% of these cases a level of IgG4 of less than 0.05 g/l.

Adolescent↗
PubMed1991

Isotype distribution of mucosal IgG-producing cells in patients with various IgG subclass deficiencies.

The subclass distribution of IgG-producing immunocytes was examined by immunohistochemistry in nasal and rectal mucosa of infection-prone patients with untreated IgG subclass deficiencies. Biopsy specimens from the two sites were obtained in 18 clinically and serologically well-characterized adult subjects; only a nasal or rectal sample was available from nine similar patients. Chronic lung disease was common in the patient groups with selective serum IgG1 deficiency and combined IgG1 and IgG3 deficiency, whereas the other categories of patients had mainly upper airway and other mild infections. Serum IgG2 or IgG3 deficiency was usually expressed also at the cellular level in rectal mucosa, and the proportion of rectal IgG1 cells was significantly correlated with the IgG1 level (r = 0.90, P less than 0.001). Likewise, there tended to be a decreased expression of the actual subclass at the cellular level in nasal mucosa of patients with serum IgG1 or IgG2 deficiency. Conversely, the median nasal proportion of IgG3 cells was remarkably unaffected by a deficiency of this subclass in serum and rectal mucosa. Interestingly, these patients rather tended to have raised IgG3 and reduced IgG2 cell proportions in their nasal mucosa, although this apparent local IgG3 compensation was nevertheless strongly correlated with the serum IgG3 level (r = 0.87, P less than 0.002). These disparities may reflect different antigenic and mitogenic exposure of the two tissue sites; for example, a persistent protein bombardment of the nasal mucosa that could conceivably override locally a B cell maturation defect. The possible clinical consequences of such variable mucosal expression of IgG subclass deficiencies remain to be studied.

Adult↗