Concordance study and population frequencies for 16 autosomal STRs analyzed with PowerPlex® ESI 17 and AmpFℓSTR® NGM SElect™ in Somalis, Danes and Greenlanders.

A concordance study of the results of PowerPlex(®) ESI 17 and AmpFℓSTR(®) NGM SElect™ kits obtained from 591 individuals from Somalia (N=198), Denmark (N=199) and Greenland (N=194) was performed. Among 9456 STR types, seven discordant results were found with the two kits: one observed in the D19S433 system in an individual from Denmark and six in the SE33 system in six individuals from Somalia. Sequencing of SE33 in the six samples with discordant results showed G>A transition 15bp downstream of the repeat unit in three of the individuals, and G>A transition 68bp downstream of the repeat unit in the other three individuals. Population data for 16 autosomal STR systems analyzed in 989 individuals from Somalia, Denmark and Greenland are also presented. The highest mean heterozygosity was observed in Danes (82.5%). With the exception of D8S1179 in Danes, no significant deviations from Hardy-Weinberg expectations were observed. Only one pair of systems (D12S391 and D18S51) showed significant allelic association in Greenlanders (after Holm-Sidák correction). A MDS plot drawn from pairwise FST values calculated between 21 populations showed a clear displacement of the Greenlandic population versus the other ones included in the analyses. The highest combined chance of exclusion and power of discrimination was observed for Danes reaching values of 99.9999987% and 1 in 1.8×10(21), respectively.

Development and validation of a radioligand binding assay to measure insulin specific IgG subclass antibodies in human serum.

The objective was to develop and validate a radioligand binding assay for insulin antibodies (IABs) of the IgG1, IgG2, IgG3, and IgG4 subclasses in human serum. The validation studies focused on determining specificity, capacity, linearity, sensitivity, and precision of each assay. It was seen that our assay for IAB IgG subclasses is specific and has sufficient capacity to measure each of the subclasses in human serum. Moreover, the linear region and limits of detection and quantitation for each assay are clearly determined.

A case of spurious hypercalcitoninemia: a cautionary tale on the use of plasma calcitonin assays in the screening of patients with thyroid nodules for neoplasia.

The measurement of plasma CT has an important role as a screening test for medullary thyroid carcinoma (MTC) in patients with thyroid nodules. However, elevated plasma CT levels should be interpreted within the context of the overall clinical picture in each individual case and carefully validated before therapeutic decisions are made. We present the case of a 17-yr-old girl who was referred to us with a thyroid nodule and elevated plasma CT levels, as measured by a one-site RIA not involving prior plasma extraction. Plasma CT was re-measured using two different methods, a RIA with prior plasma extraction and a two-site immunochemiluminometric assay (ICMA), and was either very low or undetectable. Subsequently, samples were re-assayed using the initially applied CT RIA; plasma CT levels were again found to be elevated. These elevations were of a spurious nature, probably caused by the presence of an unidentified substance in the patient's plasma interfering with the measurement of CT in the initially used RIA. Our patient was eventually diagnosed with Hashimoto's thyroiditis, and had no evidence of MTC. As several conditions can cause either true or spurious hypercalcitoninemia, we suggest that elevated plasma CT levels should be confirmed at least once before other extensive diagnostic investigations are initiated or thyroidectomy is recommended. Finally, the assay selected should detect only the mature CT molecule.

Insulin-like growth factor-I (somatomedin C) levels in chronic fatigue syndrome and fibromyalgia.

OBJECTIVE: Fibromyalgia (FM) and chronic fatigue syndrome (CFS) are similar conditions characterized by substantial fatigue, diffuse myalgias, sleep disturbances and a variety of other symptoms. Many patients with CFS meet strict criteria for FM. Recently, low insulin-like growth factor-I (IGF-I) levels have been demonstrated in patients with FM, suggesting that disruption of the growth hormone-IGF-I axis might explain the link between the muscle pain and poor sleep. Our goal was to determine whether IGF-I levels are decreased in CFS, and whether such findings are restricted to patients with concurrent FM. METHODS: Radioimmunoassays were used to determine serum concentrations of IGF-I and its binding protein, (IGFBP-3). Subjects were 3 patients seen in a referral clinic for chronic fatigue: 15 patients with CFS, 15 who met criteria for both CFS and FM (CFS-FM), 27 with FM alone; and 15 healthy control (HC) subjects. RESULTS: Patients and control subjects had similar demographic and clinical characteristics. No significant differences were observed among any of the 3 patient groups and control subjects in the mean concentration of either IGF-I or IGFBP-3. Likewise, the proportion of subjects with values above or below the laboratory's reference range did not differ for IGF-I or IGFBP-3. CONCLUSIONS: These findings suggest the disruption of the growth hormone-IGF-I axis previously demonstrated in FM patients is not evident in a referral population of patients with CFS, CFS-FM, or FM.

Prediction of neonatal hyperthyroidism in infants born to mothers with Graves disease.

OBJECTIVE: To determine whether determinations of thyrotropin-receptor antibody (TRAb) levels in newborn infants of women with Graves disease would predict which infants will have hyperthyroidism. METHODS: The TRAb levels, assayed in the sera of 14 infants born to 14 women with Graves disease, were measured sequentially in the infants with hyperthyroidism during the course of antithyroid medication therapy. RESULTS: Seven infants had TRAb values less than 0.15 and remained euthyroid. In seven infants whose initial TRAb values were more than 0.25 (range, 0.48 to 0.88), clinical and biochemical signs of hyperthyroidism developed. The infants were treated with antithyroid medication until day 57 to day 123 of life. Therapy was discontinued when the infants were free of symptoms and when serum thyroxine and triiodothyronine and free thyroxine levels remained normal during therapy with decreasing doses of antithyroid medication. When the medication was discontinued, TRAb values were less than 0.20. CONCLUSIONS: Infants born to mothers with Graves disease with initial TRAb values less than 0.15 remained euthyroid. The TRAb values greater than 0.25 were associated with the development of neonatal hyperthyroidism. During treatment of neonatal hyperthyroidism, TRAb values less than 0.20 may be helpful in deciding when to withdraw antithyroid medication.

Detection of human growth hormone receptors on IM-9 cells and peripheral blood mononuclear cell subsets by flow cytometry: correlation with growth hormone-binding protein levels.

We have developed a method using flow cytometry to identify fluorescein-conjugated GH receptors (GHR) on IM-9 lymphocytes and circulating peripheral blood mononuclear cell subsets. Binding to IM-9 cells and peripheral blood mononuclear cells was concentration dependent and could be competitively blocked by the addition of unlabeled human GH, but not by the addition of rat or bovine GH or human insulin or PRL. Using two-color flow cytometric analysis, fluorescein-conjugated human GHR were readily detected on more than 90% of B lymphocytes and monocytes, but only variably on T lymphocytes. B Lymphocytes and monocytes had approximately 6000 GHR/cell. Using two-color flow cytometry, we identified GHR on circulating B lymphocytes in subjects with GH deficiency (n = 9), precocious puberty (n = 6), and Turner syndrome (n = 5) and in seven subjects with miscellaneous disorders, including familial short stature, bone dysplasia, Crohn disease, congenital adrenal hyperplasia, and acromegaly. The percentage of B lymphocytes expressing GHR in subjects with GH deficiency (mean +/- SD, 95 +/- 9%), precocious puberty (91 +/- 15%), and Turner syndrome (84 +/- 15%) was not different from that in normal volunteers (90 +/- 12%; n = 14). In 10 subjects, serum GH-binding protein levels were assayed simultaneously with B lymphocyte GHR. GH-binding protein was normal in all (mean, 1255 pmol/L; range, 773-1809). There was a good correlation between GHR expression on B lymphocytes and GH-binding protein levels (r = 0.75; P = 0.01). We postulate that GHR found on circulating B lymphocytes may contribute to the pool of receptors identified in serum as GH-binding proteins. Two-color flow cytometry appears to be an effective method for the detection of GHR on circulating peripheral blood mononuclear cell subsets. The evaluation of GHR on circulating B lymphocytes may prove to be a useful means of evaluating GH-GHR interactions in subjects with growth disorders.

Normal ranges for immunochemiluminometric gonadotropin assays.

OBJECTIVE: We sought to establish normative data for spontaneous and gonadotropin-releasing hormone (GnRH)-stimulated serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels measured by new immunochemiluminometric assays (ICMA) in children and adolescents. METHODS: Random serum samples were obtained from 375 normal subjects (0.1 to 17.7 years, 230 female subjects). Intravenous GnRH stimulation tests were performed in 41 normal subjects (4.8 to 18 years, 20 female subjects). Normal ranges were calculated by age and Tanner stage. Immunochemiluminometric assays of LH and FSH concentrations were compared with levels obtained by a sensitive immunofluorometric assay and a less sensitive radioimmunoassay. RESULTS: Random gonadotropin concentrations in normal children followed the pattern of transient elevation in infancy, low but measurable prepubertal levels, and markedly increased values at puberty. Spontaneous LH levels were higher in male infants but were not statistically different in boys and girls after infancy. Mean prepubertal LH was 0.04 +/- 0.04 IU/L (n = 66), rising 100-fold during puberty. Spontaneous FSH levels were much higher than LH values, were higher in female infants, and rose threefold at puberty. Peak GnRH-stimulated LH was identical in prepubertal boys and girls (1.8 +/- 1.3 IU/L, n = 17) and increased 20-fold at puberty. Mean peak GnRH-stimulated FSH was highest in prepubertal female subjects. Luteinizing hormone values measured by ICMA and immunofluorometric assay were highly correlated, but radioimmunoassay levels diverged markedly from ICMA levels at lower concentrations. Because absolute levels were higher, FSH values correlated adequately in the three assays throughout the normal physiologic range. CONCLUSIONS: Measurement of LH by ICMA is much more sensitive than older assay methods. Spontaneous LH can be accurately measured by ICMA to the very low levels present in normal prepubertal children, providing a potentially important biochemical discriminator of pubertal status. An ICMA GnRH-stimulated LH level greater than 5 IU/L is suggestive of maturing gonadotropin secretion. The ICMA LH assays provide significant enhancement in sensitivity; these assays should be used when levels may be low, and by their accuracy may reduce the time and expense of testing procedures.

Spontaneous serum gonadotropin concentrations in the evaluation of precocious puberty.

OBJECTIVE: We assessed the utility of spontaneous and gonadotropin-releasing hormone (GnRH)-stimulated serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels measured by new immunochemiluminometric assays in the evaluation and monitoring of precocious puberty. METHODS: We evaluated serum gonadotropin values from intravenous GnRH stimulation tests in 49 girls with clinical signs suggesting central precocious puberty (CPP). Because GnRH-stimulated LH has been considered the standard for diagnosing CPP, we used it as the basis for comparison with GnRH-stimulated FSH levels and spontaneous LH and FSH measured by immunochemiluminometric assay. RESULTS: Twenty-six patients had a peak serum LH value above the +2 SD threshold for normal prepubertal female subjects (LH > 5 IU/L). The GnRH-stimulated FSH values had a narrow range and did not discriminate patients with CPP. In contrast, elevations in spontaneous LH and FSH were found to be specific for CPP. Spontaneous LH levels correlated strongly with peak stimulated LH levels in subjects with precocious puberty (r = 0.79) or in control subjects (r = 0.93, both p (0.0001). Spontaneous LH levels in excess of 0.1 IU/L detected true puberty with 94% sensitivity and 88% specificity. Random LH levels in excess of 0.3 IU/L had 100% specificity for CPP. CONCLUSIONS: The GnRH-stimulated FSH levels do not adequately differentiate children with and without CPP and have limited utility in the evaluation of precocious puberty. Spontaneous FSH levels are elevated in CPP with fair sensitivity and marked specificity. Elevated random LH, measured by third-generation assay such as immunochemiluminometric assay, is strongly correlated with and highly predictive of elevated peak GnRH-stimulated LH, and is a useful screening tool for CPP.

Assay systems for the growth hormone-binding protein.

The first method used for detection of growth hormone-binding protein (GHBP) in biological fluids was based on the incubation of the sample with radiolabeled GH followed by separation of bound and free GH by gel exclusion chromatography. Recently, other methods have been developed which are faster and easier to use. These methods include variants of the original binding/column assay (e.g., separation of bound and free GH is obtained by immunoprecipitation, charcoal adsorption, ion exchange chromatography, or HPLC), and a ligand-mediated immunofunctional assay (LIFA), in which a monoclonal antibody is used to capture the GHBP on a microtiter plate; all binding sites are saturated with GH and an anti-GH antibody is used to detect the amount of GH (endogenous and exogenous) bound to the GHBP. To permit comparison of results obtained by different methods we have cross-validated the LIFA with two different binding assays: (i) the original long column assay (column assay), and (ii) an assay based on immunoprecipitation (RIPA) of the GH/GHBP complex with an anti-GHBP antibody.

Normative data for insulin-like growth factors (IGFs), IGF-binding proteins, and growth hormone-binding protein in a healthy Spanish pediatric population: age- and sex-related changes.

The normal values of insulin-like growth factors (IGFs) after extraction, their binding proteins, and the high affinity GH-binding protein are not well established in infancy or childhood. We report the relationship between serum IGF-I, IGF-II, their binding proteins IGFBP-1 and IGFBP-3, and GH-binding protein in 600 normal Spanish children who were divided into 5 groups according to Tanner stage: I, 150 males and 102 females; II, 40 males and 42 females; III, 45 males and 45 females; IV, 42 males and 55 females; and V, 23 males and 56 females. Serum IGF-I levels increase slowly during childhood in both sexes, exhibiting a dramatic increase during puberty and a significant decline [P < 0.001, by analysis of variance (ANOVA)] during adulthood. The pubertal peak occurs approximately 2 yr earlier in girls than in boys. In contrast, serum IGF-II levels remain stable throughout childhood, showing no pubertal peak. In boys, there is a significant decline in IGF-II levels during adulthood (P < 0.001). Serum IGFBP-3 levels show a pattern similar to that of IGF-I, with a significant increase during childhood and a significant decline during adulthood (P < 0.001, ANOVA) in both males and females. In contrast, serum IGFBP-1 levels decrease dramatically during childhood in both boys and girls (P < 0.001 and P < 0.005, respectively, by ANOVA). A significant decline in serum GH-binding protein levels is observed between prepubertal and pubertal children of both sexes (P < 0.001). There is a close linear correlation between the sum of serum IGF-I plus IGF-II levels vs. serum IGFBP-3 (r = 0.724; P < 0.0001). In contrast, there is a nonlinear correlation between serum IGF-I vs. serum IGFBP-3 (concave curve) as well as between serum IGF-II and serum IGFBP-3 (convex curve). A negative correlation was found between serum IGF-I vs. IGFBP-1 (r = -0.51; P < 0.0001) as well as between the sum of serum IGF-I plus IGF-II vs. IGFBP-1 (r = -0.47; P < 0.0001), but not between serum IGF-II and IGFBP-1. These data emphasize that when these tests are performed in the clinic, their interpretation should be based upon age- and sex-specific criteria.

Plasma IGFBP-3 and its relationship with quantitative growth hormone secretion in short children.

OBJECTIVE: We assessed the relationship between serum IGFBP-3 levels with IGF-I and quantitative GH secretory status in poorly growing children. DESIGN: We studied the relationship between 24-hour integrated concentration of GH, peak GH to paired sequential stimulation tests, IGF-I and the IGFBP-3 serum levels. PATIENTS: One hundred and two children (82 males, 20 females, age 11.7 +/- 2.7 years) with short stature (height -2.6 +/- 0.7 SDS) were studied. MEASUREMENTS: Quantitative GH secretory status was assessed by the 24-hour integrated GH and by response to arginine and insulin stimulation. GH, IGFBP-3 and IGF-I were measured by radioimmunoassay. To adjust for age and gender, IGFBP-3 levels were converted to SD score. RESULTS: IGFBP-3 SDS was strongly correlated with IGF-I SDS (r = 0.64, P < 0.0001), and weakly with peak GH (r = 0.28, P < 0.0004), but not with the integrated GH concentration (r = 0.07, P < 0.46). IGFBP-3 SDS increased with pubertal maturation (P < 0.0001). There was no difference in mean IGFBP-3 SDS in subgroupings of the patients based on the results of their quantitative GH tests. CONCLUSION: In short children, IGFBP-3 levels increase with puberty, are strongly correlated with IGF-I levels, weakly correlated with peak response to GH stimulation tests, but not correlated with integrated GH. Consequently, diagnostic classifications of patients based on quantitative measurements of GH secretion and IGFBP-3 differ.

Effects of maturational stage on insulin sensitivity during puberty.

During puberty, plasma insulin levels increase, and insulin sensitivity decreases along with multiple other physical and hormonal changes. To determine 1) the time course of the decrease in insulin sensitivity in relationship to Tanner stage of genital development, and 2) how this change relates to changes in GH secretion, insulin-like growth factor-I (IGF-I), IGF-binding protein-3, and gonadal steroid secretion, we studied 58 healthy children and adolescents (34 males and 24 females; age 7-15 yr) using overnight GH sampling and frequently sampled iv glucose tolerance tests. The insulin sensitivity index (ISI) was calculated using the program MINMOD. ISI differed significantly by Tanner stage (P < 0.05, by analysis of variance) with a decrease from Tanner stage 1 to 2 (P < 0.05). IGF-I and IGF-binding protein-3 followed opposite patterns to ISI, with lower levels in Tanner stage 1 than in stages 2-5 (P < 0.05). Mean GH levels did not increase until Tanner stage 4 (P < 0.05) and then fell during Tanner stage 5. Multiple linear regression analysis revealed negative relationships among ISI, IGF-I, and body mass index. No relationship was found with GH. We conclude that the pubertal change in ISI is not necessarily associated with increased GH secretion, but is associated with increased GH peripheral effect, as indicated by the relationship between ISI and IGF-I.

The value of urinary growth hormone determination for assessment of growth hormone deficiency and compliance with growth hormone therapy.

OBJECTIVE: To compare the 24-hour integrated concentrations of plasma growth hormone with growth hormone levels in a simultaneously collected sample of urine. SETTING: Pediatric endocrine diagnostic unit. PATIENTS: Forty-six children (41 male and five female) aged 6 to 19 years underwent measurement of integrated concentrations of growth hormone and simultaneous urine collection. MEASUREMENTS AND RESULTS: Integrated concentration of plasma growth hormone was correlated with urinary growth hormone levels from both the 24-hour (r = .67; P < .0001) and 12-hour overnight (r = .52; P < .001) measurements. Peak growth hormone response to paired stimulation was not correlated with either the 24-hour (r = .26; P < .23; n = 28) or 12-hour (r = .16; P < .48; n = 28) urinary growth hormone levels. The mean 24- and 12-hour urinary growth hormone levels for the patients with normal integrated concentrations of growth hormone were significantly higher than those in patient groups having subnormal integrated concentrations of growth hormone (P < .05). However, there was considerable overlap in the 12- and 24-hour urinary growth hormone levels between the patients with normal and those with subnormal integrated concentrations of growth hormone. Only one patient who had subnormal integrated concentrations of growth hormone had a 24-hour urinary growth hormone level higher than 9 ng, and none had a 12-hour urinary growth hormone level higher than 7 ng. The mean 12- and 24-hour urinary growth hormone levels were significantly higher in patients who received growth hormone injection than in those with normal spontaneous integrated concentrations of growth hormone and had no overlap with patients who had subnormal integrated concentrations of growth hormone. CONCLUSIONS: (1) Urinary and integrated concentrations of plasma growth hormone are correlated; (2) patient diagnoses based on integrated plasma growth hormone levels exhibit a high degree of overlap of urinary growth hormone; and (3) urinary growth hormone levels can serve to monitor compliance with growth hormone therapy.

Insulin-like growth factor binding protein-3 in normal pubertal girls.

IGFBP-3 concentrations rise in the second decade of life. To test the hypothesis that the stage of pubertal development, independent of chronological age, was associated with these increases we measured serum IGFBP-3 concentrations by radioimmunoassay in 324 sixth and seventh grade girls (12.3 +/- 0.7 years) at the beginning of a multisite school-based health curriculum. The mean (+/- SD) serum IGFBP-3 among the 242 girls with complete data was 4.0 +/- 0.7 mg/l. Pubertal stage was significantly associated with IGFBP-3 (p less than 0.0001, ANOVA). Mean concentrations rose from 3.5 +/- 0.7 mg/l among those with the earliest pubertal stages to 4.2 +/- 0.7 mg/l among the mature girls. IGF-I and IGFBP-3 concentrations were significantly correlated (Spearman's r = 0.43, p less than 0.0001). After controlling for the association between pubertal development and IGFBP-3 concentrations, only the waist/hip ratio, among the various measures of body composition, was significantly associated with IGFBP-3 concentration (Spearman's r = -0.23, p = 0.0002). Likewise, none of the measures of nutrition: intake of total calories, protein, fat and carbohydrate; serum iron; red cell mean corpuscular volume; or cholesterol; were significantly associated with IGFBP-3 concentrations. There was, however, a small, but significant association between IGFBP-3 concentrations and both serum transferrin and blood hemoglobin concentrations. Pubertal stage has a significant impact on IGFBP-3 concentrations and those attempting to utilize IGFBP-3 concentrations during adolescence should be cognizant of the subject's pubertal stage.

Effect of epidermal Langerhans cells from melanoma patients on lymphoproliferative responses.

Langerhans cells (LC) are potent antigen-presenting dendritic cells essential for cutaneous immune responses. LC are reduced in number in the epidermis adjacent to primary melanomas and increase in number in the lymphoid infiltrate that accumulates in the dermis deep to such tumours. The present study was undertaken to assess whether the reduction in epidermal LC was accompanied by alterations in their functional competence. We evaluated the capacity of LC from melanoma patients to augment lymphocyte responses to phytohaemagglutinin (PHA), tetanus toxoid and melanoma-associated antigens. Using a panning method to bind Fc receptor positive (FcR+) cells we separated LC-enriched (FcR+) and depleted (FcR-) fractions of epidermal cells. Lymphocyte responses to PHA and tetanus toxoid were increased in the presence of LC-enriched cell populations, but not in the presence of LC-depleted epidermal cells. In preliminary experiments LC-enriched cell populations did not help initiate detectable in vitro lymphoproliferative responses to autologous metastatic melanoma cell lines, allogeneic HLA-DR+ metastatic melanoma cell lines, or a 180-190 kD melanoma tumour-associated antigen. Future studies will investigate the capacity of LC to augment responses to melanoma-associated antigens on autologous primary melanomas.

Immunopathological features of human pulmonary tumors following low-dose interleukin-2.

We administered preoperative low-dose interleukin-2 (IL-2) to 10 patients undergoing thoracotomy for pulmonary tumors. The in vivo effect of IL-2 on tumor-associated lymphocyte activity was assessed in the resected specimens by immunohistochemistry and compared with observations in 45 patients who did not receive IL-2. H & E evaluation revealed an increase in intra- and peritumoral lymphocyte infiltration in the IL-2-treated patients. Immunopathological evaluation with monoclonal antibodies revealed that this lymphocyte infiltration was predominantly CD5-positive T cells. The amount of intra- and peritumoral lymphocyte activity correlated with the dose of IL-2 administered (6000-90,000 international units/kg every 8 h for 48 h. IL-2-treated patients showed increases in T-cell-associated activation markers (IL-2 alpha-receptor, transferrin receptor and HLA-DR) on peritumoral lymphocytes, but not on intratumoral lymphocytes. We previously reported that low-dose IL-2 increases the intrinsic natural killer cell cytotoxicity of intratumoral lymphocytes and suggest that this lymphocyte infiltration is further evidence that low-dose IL-2 can augment in vivo lymphocyte activity at the tumor site.

Immunosuppression by melanoma cells as a factor in the generation of metastatic disease.

Studies of the regional nodes (RLN) of melanoma patients, using immunohistology with anti-S-100 protein and monoclonal antibodies have shown occult tumor cells (OTC) in nodes ostensibly tumor-free by H&E staining. OTC were demonstrated in 14% of Stage I patients, mainly those with deep, thick primaries and 30% of Stage II patients, mainly those with at least 3 tumor-positive nodes on H&E. The nodes containing OTC are those nearest to tumor on the direct lymphatic pathway (dye studies). Parallel studies show nodes in the same position to be immune suppressed (histology, immunohistology, response to mitogens, alloantigens and lymphokines) and to contain many suppressor T cells (Con-A). Melanoma-derived materials (gangliosides, prostaglandins, lipoprotein antigens) downregulate lymphocyte and macrophage functions, providing a possible mechanism for the suppressed function of nodes near tumor, a suppression that may facilitate tumor cells as evidenced by the survival of OTC.

Quantitative alterations in cutaneous Langerhans cells during the evolution of malignant melanoma of the skin.

Melanomas are associated with a T-cell predominant infiltrate that may cause their regression. Langerhans cells (LC) are essential for initiation and maintenance of specific T-cell-mediate responses in the skin. Therefore, a change in this antigen-presenting LC population may alter the host response. To determine whether the LC population varies during the evolution of primary cutaneous melanoma 32 melanocytic lesions, nevi, and cutaneous melanomas were studied by quantitative immunohistology. The monoclonal antibody, Leu-6, and the avidin biotin complex immunoperoxidase method were used to identify LC. Compared with histologically normal melanoma-adjacent skin, epidermal LC were depleted above "deeply invasive" melanomas but were relatively unchanged above nevi, "early invasive" melanomas, and cutaneous metastatic melanoma nodules. Dermal LC were significantly increased around in situ and "early invasive" melanomas but not around "deeply invasive" melanomas or cutaneous metastatic nodules. Dermal LC are thus associated with early transformed melanocytes and may present neoantigens to T lymphocytes in situ or after LC maturation in the draining lymph node. Melanoma-associated LC decline in number as melanoma progresses.

Inhibition of lymphocyte motility by interleukin 2.

These studies described were designed to determine whether interleukin 2 (IL-2) inhibits lymphocyte migration. The human lymphoblastoid cell line QIMR-WIL was used as an indicator of lymphocyte migration inhibition. Interleukin 2 inhibited QIMR-WIL migration in a dose-dependent manner, high doses of IL-2 (100 units) being strongly inhibitory, and low doses (12.5 units) less inhibitory. Purified natural IL-2 and recombinant IL-2 both inhibited QIMR-WIL migration. The effect of IL-2 on lymphocyte migration was specific. When the IL-2 receptors were blocked with anti-Tac (anti-IL-2 receptor) antibodies, the inhibitory effect of IL-2 was significantly reduced. Similarly antibody to IL-2 blocked the inhibitory effect of IL-2. Lymph node lymphocytes were also used as indicator cells in migration studies and IL-2 inhibited their motility. These data suggest a role for IL-2 in inhibiting lymphocyte migration similar to that of lymphocyte migration inhibition factor produced by antigen- or mitogen-stimulated T lymphocytes. While it is widely recognized that lymphocyte motility can be reduced by lymphocyte migration inhibition factor, these data indicate that IL-2 can also reduce lymphocyte motility.