HLA class II alleles and susceptibility and resistance to insulin dependent diabetes mellitus in Mexican-American families.

The role of HLA class II alleles in genetic predisposition to insulin dependent diabetes mellitus (IDDM) was examined by PCR/oligonucleotide probe typing of 42 Mexican-American IDDM families derived from Hispanic Caucasians and Native Americans. All high risk haplotypes (HLA-DR3 and DR4) were of European origin while the most strongly protective haplotype (DRB1*1402) was Native American. Of the 16 DR-DQ DR4 haplotypes identified, only those bearing DQB1*0302 conferred risk; the DRB1 allele, however, also markedly influenced IDDM risk. The general pattern of neutral and protective haplotypes indicates that the presence of Asp-57 in the HLA-DQ beta chain does not confer IDDM protection per se and indicates that both DRB1 and DQB1 influence IDDM susceptibility as well as protection.

Cytokine response in patients with chronic infections caused by Staphylococcus aureus strains and diversification of their Agr system classes.

This study aimed to describe the levels of circulating cytokine levels produced by Th lymphocytes (IFN-γ, IL-4, IL-10, IL-17A), as well as the levels of cytokines produced by monocytes/macrophages (TNF-α, IL-1ß, IL-12), in patients with chronic infections caused by Staphylococcus aureus strains, particularly in the context of the diversification of their Agr system classes. The studies were conducted on adult patients, including 50 patients with chronic suppurative dermatitis, 40 patients with chronic infections of the upper respiratory tract and 25 healthy individuals (control group). Blood serum cytokine levels were measured by enzyme-linked immunosorbent assay (ELISA). S. aureus was detected in cultures of suppurative dermal exudates or of pharyngeal smears. Classes of Agr systems in the S. aureus strains were identified using polymerase chain reaction (PCR). In both groups of patients, on average, levels of IFN-γ were doubled, while levels of IL-17A were increased by 2.5-fold, which, however, was not accompanied by increased levels of TNF-α or IL-12. The data indicate that the development of S. aureus infection among the studied patients was linked to an impoverished cytokine response of monocytes/macrophages, while that induced by the pathogen lymphocytes Th17/Th1 may be responsible for promotion of the chronic inflammatory response. In parallel, no quantitative or qualitative differences were disclosed between cytokine responses manifested by subgroups of patients infected with S. aureus strains belonging to class IV Agr, as compared to patients infected with strains of classes I to III Agr. Nevertheless, in the patients, strains belonging to class IV Agr prevailed, which points to the preferential relationship between the class and the pathogenicity of S. aureus.

Oral Lactobacilli and salivary acidic proline-rich proteins (APRP-1/2) in dental caries.

A previous study shows that levels of acidic salivary proline-rich phosphoproteins-1/2 (APRP-1/2) increase with caries severity. The aim of this study was to examine whether this relationship also depends on the presence of H2O2-producing strains of Lactobacillus spp. Adults with severe caries (decayed, missing, and filled teeth (DMFT) > 13.9, n = 28) were compared with similarly aged adults who had minimal caries (DMFT < 5, n = 20). A total of 48 samples of whole unstimulated saliva were collected in the morning and centrifuged. Lactobacillus spp. were isolated from the sediment in Rogosa agar and peroxide (H2O2) production was determined by growing the isolates on TMB-Plus agar. Salivary APRP-1/2 content in the saliva supernatant was estimated using an enzyme-linked immunosorbent sandwich assay (ELISA). Lactobacilli were present in 67% of both caries groups but were H2O2 positive only in the minimal caries group. Irrespective of the presence of Lactobacilli, the total content of APRP-1/2 proteins was 34.5 ± 4.9 ng/ml in severe caries but just under half this in minimal caries. We conclude that Lactobacillus spp. was absent from about a third of the severe and minimal caries groups, and H2O2-producing strains were present only in the minimal caries group. The severe caries group possessed twice the content of salivary APRP 1/2 proteins as the minimal caries group. The implications of these findings for caries development are discussed.

Heterogeneity of plasma glucagon. Circulating components in normal subjects and patients with chronic renal failure.

Plasma immunoreactive glucagon (IRG) concentrations were measured in 36 patients with chronic renal failure (CRF) and 32 normal subjects. In addition, the components of circulating IRG were analyzed by gel filtration in the fasting state and after physiological stimuli. Fasting IRG was elevated (P less than 0.001) in CRF patients (534 +/- 32 pg/ml) compared with the levels found in healthy subjects (113 +/- 9 pg/ml). Oral glucose suppressed plasma IRG in CRF patients from a basal level of 568 +/- 52 to a nadir of 354 +/- 57 pg/ml (120 min). This degree of suppression (38%) was comparable to that found in normal subjects (basal = 154 +/- 20 to 100 +/- 23 pg/ml) at 120 min (35%). Intravenous infusion of arginine (250 mg/kg) resulted in a 71% rise in IRG in CRF patients and a 166% increase in normal subjects. Gel filtration of fasting plasma from CRF patients showed three major peaks. The earliest (A) was found in the void volume (mol wt greater than 40,000) and constituted 16.5 +/- 4.7% of the elution profile. The middle peak (B) eluted just beyond the proinsulin marker (approximately 9,000 mol wt) and constituted the largest proportion of the elution profile (56.5 +/- 3.4%). The third peak (C) coincided with the standard glucagon and [125I]glucagon markers (3,485 mol wt) and comprised 27.0 +/- 4% of the IRG profile. In contrast, only peaks A and C were found in fasting plasma of normal subjects (53.6 +/- 10.4% in A and 46.4 +/- 10.4 in C). After oral glucose, glucagon immunoreactivity in the 3,500 mol wt peak (C) was markedly suppressed, while the B peak in patients with CRF declined to a lesser extent. The A peak in both groups was unchanged. After an arginine infusion only the C peak increased in both groups of subjects. Gel filtration of plasma in 3 M acetic acid gave similar profiles to those obtained in glycine albumin buffer. Exposure of serum to trypsin indicated that the B and C peaks were digestible, while the A peak was resistant to the action of the enzyme. In one sample, peak C increased after a 2-h exposure of serum to trypsin. We conclude that circulating IRG in normal subjects and patients with CRF is heterogenous. The hyperglucagonemia of renal failure is largely due to an increase in IRG material of approximately 9,000 mol wt, consistent with proglucagon, although the 3,500 mol wt component is also considerably elevated (threefold). The significance of circulating IRG levels should be interpreted with caution until the relative biological activity of the three components is established.

Human insulin B24 (Phe----Ser). Secretion and metabolic clearance of the abnormal insulin in man and in a dog model.

We have already demonstrated that a hyperinsulinemic, diabetic subject secreted an abnormal insulin in which serine replaced phenylalanine B24 (Shoelson S., M. Fickova, M. Haneda, A. Nahum, G. Musso, E. T. Kaiser, A. H. Rubenstein, and H. Tager. 1983. Proc. Natl. Acad. Sci. USA. 80:7390-7394). High performance liquid chromatography analysis now shows that the circulating insulin in several other family members also consists of a mixture of the abnormal human insulin B24 (Phe----Ser) and normal human insulin in a ratio of approximately 9.5:1 during fasting. Although all affected subjects show fasting hyperinsulinemia, only the propositus and her father are overtly diabetic. Analysis of the serum insulin from two nondiabetic siblings revealed that normal insulin increased from approximately 2 to 15% of total serum insulin after the ingestion of glucose and that the proportion of the normal hormone plateaued or fell while the level of total insulin continued to rise. Animal studies involving the graded intraportal infusion of equimolar amounts of semisynthetic human [SerB24]-insulin and normal human insulin in pancreatectomized dogs (to simulate the secretion of insulin due to oral glucose in man) also showed both a rise in the fraction of normal insulin that reached the periphery and the attainment of a brief steady state in this fraction while total insulin levels continued to rise. Separate experiments documented a decreased hepatic extraction, a decreased metabolic clearance rate, and an increased plasma half-life of human [SerB24]-insulin within the same parameters as those determined for normal human insulin. These results form a basis for considering (a) the differential clearance of low activity abnormal insulins and normal insulin from the circulation in vivo, and (b) the causes of hyperinsulinemia in both diabetic and nondiabetic individuals who secrete abnormal human insulins.

Spontaneous hyperglycemia and impaired glucose tolerance in athymic nude BALB/c mice.

Basal plasma glucose, glucose tolerance, and insulin secretion were investigated in young and mature athymic nude BALB/c mice and in age-matched controls. Basal plasma glucose levels in male athymic nude mice were similar to those of controls at 1, 3, and 4 wk of age. At 6, 8, and 12 wk of age, male athymic nudes had significantly higher basal plasma glucose levels when compared with controls (P less than 0.01). Plasma immunoreactive insulin concentrations were similar in athymic nudes and controls at 1 wk of age, but at 3 wk of age and subsequently at 6, 8, and 12 wk athymic nude mice had significantly decreased insulin levels when compared with their age-matched controls (P less than 0.05). We found impaired glucose tolerance in male athymic nude mice at all age groups when compared with both female athymic nudes and control BALB/c mice. The discovery of a spontaneous diabetic syndrome (hyperglycemia, impaired glucose tolerance, and decreased insulin secretion) in a colony of athymic nude mice may provide an excellent model for studying the genetics and interactions between the immune and endocrine systems.

High prevalence of diabetes in young adult Ethiopian immigrants to Israel.

We performed oral glucose tolerance tests in 158 Ethiopian immigrants to Israel. The subjects were less than 30 yr of age, had lived in Israel less than or equal to 4 yr, and originated from villages in the Gondar and Ambovar regions of Ethiopia. Most had been subjected to famine conditions in Ethiopia and/or extreme hardship in Sudan before or during immigration. All were lean. They revealed a profound change in dietary habits since their arrival in Israel, with consumption of large amounts of refined carbohydrate in place of spicy stews and injura (Ethiopian pita) that had constituted dietary staples in better times in Ethiopia. According to National Diabetes Data Group criteria, 14 (8.9%) of the subjects had diabetes, and another 14 (8.9%) had impaired glucose tolerance. In addition, 13 subjects had a dramatic increase in capillary blood glucose levels (greater than 300 mg/dl) 1 h after ingestion of 75 g glucose, despite fasting and 2-h values well within the normal range, and they complained of associated symptoms during the 1st h of testing. Eleven of 137 men and 3 of 21 women had diabetes; 7 (5.1%) of the men and 7 (33%) of the women had impaired glucose tolerance. These results indicate a high prevalence of diabetes among young adult Ethiopian immigrants of relatively short residency in Israel, for which the factors responsible warrant further investigation.

HLA-DRw antigens in Mexican-American and Black-American diabetic patients.

HLA-A, - B, and -C antigens were studied in 67 Mexican-American and 38 black-American diabetic patients who had the onset of their disease before age 31 yr. Control populations consisted of 322 Mexican-American and 367 black-American subjects for HLA-A, -B, and -C antigens. In addition, HLA-DRw antigens were studied in 60 Mexican-American and 34 black-American diabetic patients. Control populations for HLA-DRw antigens consisted of 189 Mexican-American and 145 black-American subjects. We found that juvenile-onset--diabetic patients of Mexican-American origin who had the onset of their disease before age 19 demonstrated a significant increase in HLA-DRw4. HLA-DRw4 was also significantly increased in black-American patients with juvenile-onset diabetes mellitus. HLA-DRw2 was not detected in any patient with juvenile-onset diabetes in either ethnic group. A significant association was found between HLA-B18 and HLA-DRw3 in Mexican-American juvenile-diabetic patients. These findings, which are comparable to those in similar Caucasian patients, provide additional information to support the hypothesis that HLA-DRw antigens play a major role in determining the susceptibility to juvenile-onset diabetes mellitus.

Immunoreactivity of human insulin of recombinant DNA origin.

To evaluate possible advantages of human insulin of recombinant DNA origin (HI) in the treatment of diabetic patients, we compared cellular and humoral immunoreactivities of HI and porcine insulin (PI). Anti-insulin IgE bound equal amounts of 125I-HI and 125I-PI. There was no difference between HI- and PI-stimulated lymphocyte transformation indices. The binding of 125I-HI with circulating anti-insulin IgG was lower compared with 125I-PI binding (12.1 +/- 1% versus 15.4 +/- 1.5%, P less than 0.001) in 60 insulin-treated cases. Thirteen sera were selected for high antibody titers and analyzed in detail. In the competitive inhibition assays, a 50% displacement of 125I-PI required a fourfold higher concentration of HI than PI. Although total insulin binding capacities were almost equal, 63 +/- 11 nM/L for PI and 60 +/- 12 nM/L for HI, the high-affinity antibodies had significantly reduced avidity for HI compared with PI. These differences in avidities suggest that HI may be useful in treatment of immune-type insulin resistance.

Association of HLA-DPB1*0301 with IDDM in Mexican-Americans.

Susceptibility to IDDM has been associated with specific alleles at the HLA class II loci in a variety of human populations. Previous studies among Mexican-Americans, a group ancestrally derived from Native Americans and Hispanic whites, showed that the DR4 haplotypes (DRB1*0405-DQB1*0302 and DRB1*0402-DQB1*0302) and the DR3 haplotype (DRB1*0301-DQB1*0201) were increased among patients and suggested a role for both DR and DQ alleles in susceptibility and resistance. Based on the analysis of 42 Mexican-American IDDM families and ethnically matched control subjects by polymerase chain reaction/sequence-specific oligonucleotide probe typing, we report an association of IDDM with the DPB1 allele, *0301 (relative risk = 6.6; P = 0.0012) in this population. The analysis of linkage disequilibrium patterns in this population indicates that the observed increased frequency in DPB1*0301 among patients cannot be attributed simply to linkage disequilibrium with high-risk DR-DQ haplotypes. These data suggest that in addition to alleles at the DRB1 and DQB1 loci, polymorphism at the DPB1 locus may also influence IDDM risk.

Genetic and physical mapping of a type 1 diabetes susceptibility gene (IDDM12) to a 100-kb phagemid artificial chromosome clone containing D2S72-CTLA4-D2S105 on chromosome 2q33.

Polymorphic markers within the CTLA4 gene on chromosome 2q33 have been shown to be associated with type 1 diabetes. Therefore, a gene responsible for the disease (IDDM12) most likely lies within a region of <1-2 cM of CTLA4. To define more precisely the IDDM12 interval, we genotyped a multiethnic (U.S. Caucasian, Mexican-American, French, Spanish, Korean, and Chinese) collection of 178 simplex and 350 multiplex families for 10 polymorphic markers within a genomic interval of approximately 300 kb, which contains the candidate genes CTLA4 and CD28. The order of these markers (D2S346, CD28, GGAA19E07, D2S307, D2S72, CTLA4, D2S105, and GATA52A04) was determined by sequence tagged site content mapping of bacterial artificial chromosome (BAC) and yeast artificial chromosome (YAC) clones. The transmission disequilibrium test (TDT) analyses of our data revealed significant association/linkage with three markers within CTLA4 and two immediate flanking markers (D2S72 and D2S105) on each side of CTLA4 but not with more distant markers including the candidate gene CD28. Tsp analyses revealed significant association only with the three polymorphic markers within the CTLA4 gene. The markers linked and associated with type 1 diabetes are contained within a phagemid artificial chromosome clone of 100 kb, suggesting that the IDDM12 locus is either CTLA4 or an unknown gene in very close proximity.

Glyburide and glipizide in treatment of diabetic patients with secondary failures to tolazamide or chlorpropamide.

We evaluated therapeutic usefulness of the second-generation sulfonylurea agents glyburide and glipizide in non-insulin-dependent diabetic patients who were secondary failures on chlorpropamide or tolazamide. Twenty patients were treated with glyburide, and 10 of them were subsequently treated with glipizide. Fasting and postprandial serum glucose, insulin, C-peptide, glycosylated hemoglobin, urinary C-peptide, and glucose levels all failed to show significant improvement. We concluded that both glyburide and glipizide proved ineffective in the treatment of secondary failures to first-generation sulfonylureas.

Hyperinsulinism complicating control of diabetes mellitus by an artificial beta-cell.

Serum free insulin concentrations were measured in diabetic subjects given insulin intravenously by a glucose-controlled insulin infusion system ("closed-loop" artificial beta-cell) in two experimental situations: hourly during the day while given their usual diet and at short intervals after administration of a standardized test meal. Three of four subjects showed sustained hyperinsulinism when compared with matched controls during a day on their usual diet. In two of the subjects, the insulin levels also exceeded those seen in those subjects on their usual dose of subcutaneous insulin. The glucose levels were not completely normalized in the three hyperinsulinemic subjects, and the insulin levels were significantly correlated with plasma glucose levels. After the test meal, all six diabetic subjects studied showed a delayed rise in insulin levels, when compared with six normal subjects, followed by an abrupt rise in insulin levels to peak levels more than seven times those seen in normal subjects. We conclude that significant hyperinsulinism may accompany feedback-controlled intravenous insulin administration. This should be considered in interpreting studies done with such systems, and in design of control algorithms for future systems.

Different HLA haplotypes in Mexican Americans with IDDM.

The study of HLA histocompatibility antigens and insulin-dependent diabetes mellitus (IDDM) in non-White populations may provide a unique opportunity to more accurately define the diabetes susceptibility gene(s) located within the HLA region. To determine whether HLA haplotypes differ between ethnic groups, we compared 105 HLA haplotypes from 55 Mexican-American IDDM patients with 272 haplotypes from 136 IDDM patients of non-Hispanic White descent. The accurate determination of genotypes and haplotypes requires the study of family units. Therefore, all diabetic patients in this study were from studies of families having one or more siblings with IDDM. In the Mexican-American group, HLA-DR3 and -DR4 were the most common HLA-DR alleles and were present in comparable frequencies in the non-Hispanic White group (HLA-DR3, 27% of Mexican-American and 29% of non-Hispanic White haplotypes; DR4, 46% of Mexican-American and 43% of non-Hispanic White haplotypes). However, the HLA-B/DR-containing haplotypes and haplotype frequencies differed between the two groups. Several common haplotypes (B8/DR3, B15/DR4) in the non-Hispanic White group occurred less frequently in the Mexican-American group. In contrast, uncommon haplotypes in the non-Hispanic White group comprised nearly 50% of the DR4-containing haplotypes (B35/DR4, B40/DR4, B44/DR4) in the Mexican-American group. Although both DR3- and DR4-haplotype frequencies differed significantly between the two groups, the relative frequency of DR3- but not DR4-containing haplotypes was similar in both ethnic groups. This adds to the evidence suggesting that different susceptibilities are provided by the haplotypes carrying the DR3 and DR4 alleles.

Histocompatability antigens and immunoglobulin G insulin antibodies in Mexican-American insulin-dependent diabetic patients.

To determine the association of histocompatability antigens (HLA) with insulin-dependent diabetes (IDD) in Mexican-Americans, we determined HLA-A, -B, and -C specificities in 112 unrelated patients and 332 controls, and HLA-DR specificities in 85 patients and 209 controls. We also studied immunoglobulin G (IgG) insulin antibody formation in 56 Mexican-Americans with IDD, and the relationship between antibody formation and HLA-DR antigens. IDD patients have a significant increase in HLA-DR4 compared to the control population (chi 2 = 14.75; corrected P less than 0.0001). HLA-DR2 was not detected in any patient with IDD. A significant association between HLA-Aw30 and HLA-B18 was found in IDD patients (chi 2 = 9.39; P less than 0.05) as compared to controls. IgG insulin antibody formation was significantly increased in HLA-DR3- and -DR4-negative patients compared to that in patients positive for both antigens (P less than 0.05). These findings support previous observations in caucasians and black Americans indicating that HLA-DR specificities are associated with IDD and may play a role in determining its mode of inheritance, and perhaps its pathogenesis, independent of ethnic differences. HLA-DR immune-associated antigens are also of importance in determining IgG insulin antibody formation.

Heterogeneity of plasma glucagon: patterns in patients with chronic renal failure and diabetes.

Immunoreactive plasma glucagon (IRG) in normal subjects and patients with chronic renal failure, diabetic ketoacidosis and diagetic hyperosmolar syndrome circulates in several forms. In the diabetic patients most IRG eluted coincidentally with the extracted, purified pancreatic hormone (MW3500), while in normal subjects a high molecular weight component predominated. In striking contrast, the major component of plasma IRG in patients with chronic renal failure was of intermediate size (MW +/- 9000), consistent with proglucagon. The accumulation of this form of IRG suggests that the kidney plays an important role in its metabolism. If there are differences in the biological activity of the various circulating components of IRG, the significance of immunoreactive glucagon levels in some disease states will require reassessment.

Islet cell antibody-positive relatives with human leukocyte antigen DQA1*0102, DQB1*0602: identification by the Diabetes Prevention Trial-type 1.

The presence of human leukocyte antigen (HLA) haplotype DQA1*0102, DQB1*0602 is associated with protection from type 1 diabetes. The Diabetes Prevention Trial-type 1 has identified 100 islet cell antibody (ICA)-positive relatives with this protective haplotype, far exceeding the number of such subjects reported in other studies worldwide. Comparisons between ICA+ relatives with and without DQB1*0602 demonstrated no differences in gender or age; however, among racial groups, African-American ICA+ relatives were more likely to carry this haplotype than others. The ICA+ DQB1*0602 individuals were less likely to have additional risk factors for diabetes [insulin autoantibody (IAA) positive or low first phase insulin release (FPIR)] than ICA+ relatives without DQB1*0602. However, 29% of the ICA+ DQB1*0602 relatives did have IAA or low FPIR. Although half of the ICA+ DQB1*0602 relatives had a high risk second haplotype, this was not associated with the additional risk factors for diabetes. Hispanic ICA+ individuals with DQB1*0602 were more likely to be IAA positive or to have low FPIR than other racial groups. In conclusion, the presence of ICA in the relatives described here suggests that whatever the mechanism that protects DQB1*0602 individuals from diabetes, it is likely to occur after the diabetes disease process has begun. In addition, there may be different effects of DQB1*0602 between ethnic groups.

Autoantibodies and human leucocyte antigen class II in first-degree family members of Mexican-American type 1 diabetic patients.

As part of a genetic study of type 1 diabetes in Mexican-Americans, 360 first-degree relatives of 108 type 1 diabetic probands were studied. Islet cell antibody (ICA), insulin autoantibody, glutamic acid decarboxylase (GAD(65)), and protein tyrosine phosphatase autoantibodies were measured and human leucocyte antigen (HLA) class II alleles DRB1 and DQB1 genotyping was performed. ICA was positive in 37% of the probands and 5.8% of the relatives. A subgroup of 26 probands (12 ICA+, 14 ICA-) was tested for GAD(65) and was found positive. 4/14 ICA+ first-degree relatives were GAD(65) positive. Four relatives, positive for two antibodies, subsequently developed type 1 diabetes. Life-Table analysis of first-degree relatives with autoantibodies indicated an 80% disease-free survival at 3.5 yr. HLA-DRB1 was found to be associated with the presence of ICA in both probands and relatives, whereas HLA-DPB1 was associated with autoantibody in relatives of type 1 diabetic probands. These results suggest that autoimmunity occurs in type 1 diabetes families of Mexican descent in similar frequencies to that of non-Hispanic, Caucasian families. The presence of autoantibodies appears to be regulated in part by HLA class II genes, even in the absence of overt diabetes.

Acute effect of ascorbic acid infusion on carbohydrate tolerance.

Large doses (1 to 2g/3 hr) of ascorbic acid were administered intravenously to normal weight and obese, nondiabetic subjects. Glucose tolerance and fasting plasma glucose levels were unaffected, despite a 3- to 8-fold rise in plasma concentrations of the vitamin. Infusion of ascorbic acid did not alter fasting serum insulin levels in normal subjects, but was associated with lower concentrations of hormone during an intravenous glucose tolerance test. Plasma glucose, serum insulin, growth hormone, and glucagon levels in obese subjects remained unchanged during the ascorbic acid infusion.

Therapeutic effects of antibodies against adhesion molecules in murine collagen type II-induced arthritis.

Adhesion molecules play important roles in immune reactions and inflammatory processes and may constitute attractive targets for immunomodulatory approaches. In this study, blocking mAbs against a series of adhesion molecules were tested for their therapeutic effect on developing arthritis in a mouse model. MAbs were given for a period of 4 weeks at the time of exspected incidence of visible disease symptoms, i.e. 4 weeks after priming with collagen type II. A significant reduction of incidence down to values of 13% and 29% of the controls was obtained with mAbs against CD44 and alpha 4-integrin, respectively, during an observation time of 13 weeks. MAbs against CD4 and LFA-1 resulted only in weaker, non-significant effects or a delay in the incidence. MAbs against other molecules including L-selectin, ICAM-1 or VCAM-1 were not effective. The development of antibodies against collagen type II, collagen type I, proteoglycans and the immunogen, bovine collagen type II was affected by mAb treatment to a different extent. In this case, the anti CD4 mAb was the most effective, followed by the anti alpha 4-antibodies in most cases, whereas anti CD44 showed less clear effects on the development of humoral responses. In a skin delayed type hypersensitivity model analyzed for comparison, mAbs against LFA-1/ICAM-1 and alpha 4-integrin showed the largest effects on ear swelling. These data show that mAbs against several adhesion molecules are able to block selectively distinct aspects of immune reactions, and that CD44 and alpha 4-integrins could be promising targets for an immunotherapy of rheumatoid arthritis with receptor-interfering agents.