Abstract GS5-06: No survival benefit of chemotherapy escalation in patients with pCR and “high-immune” triple-negative early breast cancer in the neoadjuvant WSG-ADAPT-TN trial

Background:Immune markers such as tumor infiltrating lymphocytes (TILs), CD8, PDL1, PD1 and other protein or mRNA-based genomic markers have been identified as prognostic / predictive in TNBC regarding survival / chemotherapy (CTx) efficacy.

In the adjuvant WSG-PlanB trial, patients with high TILs and/or CD8 by mRNA had excellent outcome, irrespective of anthracycline use; in the neoadjuvant ADAPT-TN trial, high PDL1, PD1 and CD8 and/or TILs were predictive for pCR. Still, optimal markers for potential treatment de-escalation have yet to be determined. Here, we analyse for the first time impact of immune mRNA-based markers and TIL's as prognostic and predictive survival markers.

Methods: TNBC patients (ER/PR<1%, HER2-,) were randomized to neoadjuvant 4x nab-paclitaxel 125 mg/m2/gemcitabine 1000 mg/m2 d1/8 q3w (gem arm) or 4x nab-paclitaxel 125 mg/m2/carboplatin AUC2 day 1/8 3-weekly (q3w) (carbo arm). Primary endpoint of WSG-ADAPT-TN was pCR (ypT0/is/ypN0); secondary endpoints included translational analyses, e.g., TILs or expression of 119 genes by nCounter platform. Standard adjuvant chemotherapy (4xEC) was optional (not randomized) in patients achieving pCR after 12 weeks. According to protocol, 1st safety survival analysis was performed after 3y median follow-up.

Results: Present translational analysis included 306 of 336 TNBC patients (36 months median FU). pCR was associated with significantly better survival (3y EFS: 92% vs. 71%, p<.001), but despite substantially higher pCR in the carbo arm (46% vs. 29%), no significant EFS advantage was seen (p=.6) (gem: 78%; carbo: 80%; 3y-EFS).

Bivariate Spearman correlations among CD8, PD1, and PDL1 were strongly positive; their correlations with TILs were moderately positive.

Preliminary Cox analysis of EFS was performed with clinical variables (cN, cT, menopausal status); neoadjuvant study arm; pCR; TILs; proliferation markers (baseline Ki67 by IHC, scores derived from PAM50); baseline immune markers; risk scores; and individual gene expression scores previously identified as prognostic for pCR in one or both neoadjuvant arms. Independent prognostic factors included pCR, cN, Ki67, PD1, and CD8; these were entered into (prognostic) interaction analysis. The resulting model contained cN, high Ki67 and low TILs as (unfavorable) main effects and the interaction of (higher) PD1*pCR (favorable).

Among pCR patients, the groups with/without additional adjuvant CTX were similar with respect to explanatory factors. Baseline TILs, Ki67, cN, and PD1 were entered into exploratory predictive analysis; the model retained only the interaction [adjuvant CTx * (fractionally ranked) PD1]. In patients with pCR, those with low PD1 benefited from standard anthracycline-containing adjuvant CTx, whereas patients high PD1 did not with an 98% 3y-EFS.

Conclusions: Our exploratory results suggest independent prognostic impact of mRNA markers and TIL's in early TNBC. Patients with both pCR (after 12 weeks) and “high-immune” signature (defined here by PD1) had excellent 3y-EFS and may be candidates for treatment de-escalation (e.g. omission of anthracyclines), whereas “low-immune” pCR patients may benefit from standard adjuvant poly-chemotherapy.

Citation Format: Gluz O, Nitz U, Liedtke C, Prat A, Christgen M, Feuerhake F, Garke M, Grischke E-M, Forstbauer H, Braun M, Warm M, Hackmann J, Uleer C, Aktas B, Schumacher C, Kuemmel S, Pelz E, Gebauer D, Paré L, Kates R, Wuerstlein R, Kreipe HH, Harbeck N. No survival benefit of chemotherapy escalation in patients with pCR and “high-immune” triple-negative early breast cancer in the neoadjuvant WSG-ADAPT-TN trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr GS5-06.

An exploratory, open-label, randomized, multicenter study to investigate the pharmacodynamics of a glycoengineered antibody (imgatuzumab) and cetuximab in patients with operable head and neck squamous cell carcinoma

BACKGROUND

In addition to inhibiting epidermal growth factor receptor (EGFR) signaling, anti-EGFR antibodies of the IgG1 'subtype' can induce a complementary therapeutic effect through the induction of antibody-dependent cell-mediated cytotoxicity (ADCC). Glycoengineering of therapeutic antibodies increases the affinity for the Fc-gamma receptor, thereby enhancing ADCC.

PATIENTS AND METHODS

We investigated the changes in immune effector cells and EGFR pathway biomarkers in 44 patients with operable, advanced stage head and neck squamous cell carcinoma treated with two preoperative doses of either glycoengineered imgatuzumab (GA201; 700 or 1400 mg) or cetuximab (standard dosing) in a neoadjuvant setting with paired pre- and post-treatment tumor biopsies.

RESULTS

Significant antitumor activity was observed with both antibodies after just two infusions. Metabolic responses were seen in 23 (59.0%) patients overall. One imgatuzumab-treated patient (700 mg) achieved a 'pathological' complete response. An immediate and sustained decrease in peripheral natural killer cells was consistently observed with the first imgatuzumab infusion but not with cetuximab. The functionality of the remaining peripheral natural killer cells was maintained. Similarly, a pronounced increase in circulating cytokines was seen following the first infusion of imgatuzumab but not cetuximab. Overall, tumor-infiltrating CD3+ cell counts increased following treatment with both antibodies. A significant increase from baseline in CD3+/perforin+ cytotoxic T cells occurred only in the 700-mg imgatuzumab group (median 95% increase, P < 0.05). The most prominent decrease of EGFR-expressing cells was recorded after treatment with imgatuzumab (700 mg, -34.6%; 1400 mg, -41.8%). The post-treatment inflammatory tumor microenvironment was strongly related to baseline tumor-infiltrating immune cell density, and baseline levels of EGFR and pERK in tumor cells most strongly predicted therapeutic response.

CONCLUSIONS

These pharmacodynamic observations and relationship with efficacy are consistent with the proposed mode of action of imgatuzumab combining efficient EGFR pathway inhibition with ADCC-related immune antitumor effects.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01046266 (ClinicalTrials.gov).

Why one-size-fits-all vaso-modulatory interventions fail to control glioma invasion: in silico insights

Gliomas are highly invasive brain tumours characterised by poor prognosis and limited response to therapy. There is an ongoing debate on the therapeutic potential of vaso-modulatory interventions against glioma invasion. Prominent vasculature-targeting therapies involve tumour blood vessel deterioration and normalisation. The former aims at tumour infarction and nutrient deprivation induced by blood vessel occlusion/collapse. In contrast, the therapeutic intention of normalising the abnormal tumour vasculature is to improve the efficacy of conventional treatment modalities. Although these strategies have shown therapeutic potential, it remains unclear why they both often fail to control glioma growth. To shed some light on this issue, we propose a mathematical model based on the migration/proliferation dichotomy of glioma cells in order to investigate why vaso-modulatory interventions have shown limited success in terms of tumour clearance. We found the existence of a critical cell proliferation/diffusion ratio that separates glioma responses to vaso-modulatory interventions into two distinct regimes. While for tumours, belonging to one regime, vascular modulations reduce the front speed and increase the infiltration width, for those in the other regime, the invasion speed increases and infiltration width decreases. We discuss how these in silico findings can be used to guide individualised vaso-modulatory approaches to improve treatment success rates.

Abstract P2-07-01: Association of TILs with clinical parameters, recurrence score, and prognosis in patients with early HER2-negative breast cancer (BC) – A translational analysis of the prospective WSG planB trial

Introduction:

Tumor-infiltrating lymphocytes (TILs) have been associated with prognosis and with chemotherapy response among patients with BC, particularly in presence of high-risk features. The WSG planB trial randomized 2448 patients with HER2- N0/1 BC for comparison of anthracycline-free (6xTC) vs. standard anthracycline-taxane chemotherapy (4xEC-4xDoc). Recurrence Score® (RS) was incorporated for risk stratification in hormone receptor positive (HR+) BC. The present analysis focuses on the correlation of TILs with clinical/pathological parameters and their prognostic impact among planB patients.

Methods:

Stromal TILs were evaluated using a pathologist and two-observer approach. Three independent observers evaluated digital sections on H&E staining as previously suggested (Salgado et al., Ann Oncol. 2014); the median of the three values (TILmed) was used for statistical analysis. Spearman correlations of TILmed with clinical/pathological parameters (including central KI67 expression, quantitative ER measurements, nodal involvement, and RS) and univariate impact on event-free survival (EFS) were analyzed.

Results:

Our analysis included 300 patients with HR- and 1124 patients with HR+ HER2- BC. Both in HR- and HR+ BC, a significant association between TILmed and (i) central grading (correlation coefficient r=0.147, p=0.012 and r=0.195, p&lt;0.001, respectively) and (ii) central Ki67 expression (r=0.202, p=0.001 and r=0.152 and p&lt;0.001) was observed. Among HR+ cases, a significant association between TILmed and quantitative ER measurements (r=-0.412, p=0.041) and RS (r=0.190, p&lt;0.001) was found. Furthermore, univariate Cox analysis revealed a significant association between TILmed (coded as fractional rank) and event-free survival (EFS). The hazard ratio of 75th to 25th percentile was 1.58 (95%CI: 1.06-2.36, p=0.025). This impact was not separately significant in HR subgroups due to lack of events

Conclusion:

In this dataset, presence of stromal TILs was moderately associated with clinical features of high-risk breast cancer (including RS) and decreased EFS. TILs will be evaluated as a prognostic or predictive factor (in multivariate and subgroup analyses) when the outcome results are evaluated after prolonged follow up. Furthermore, an updated analysis including the complete planB dataset will be presented.

Citation Format: Liedtke C, Gluz O, Heinisch F, Feuerhake F, Kreipe HH, Clemens M, Nuding B, Kraemer S, Reimer T, Svedman C, Shak S, Nitz U, Kates RE, Harbeck N, Christgen M. Association of TILs with clinical parameters, recurrence score, and prognosis in patients with early HER2-negative breast cancer (BC) – A translational analysis of the prospective WSG planB trial. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-07-01.

Abstract P4-08-04: Assessment of Oncogenic Pathway Activation in Human Breast Cancer Tissue by Multiplex Immunohistochemistry

A multitude of cancer-associated genomic aberrations converge into activation of a limited repertoire of oncogenic ‘core’ pathways. Assessment of the activation status of such key signaling cascades is necessary to characterize pathway dependency of tumors, to predict response to specific pathway inhibitors, and to track drug effects in pharmacodynamic studies. We established a duplex immunohistochemistry (IHC) tool for the combined assessment of two key pathways involved in breast cancer biology, PI3K/AKT and MAPK. Validation of the duplex IHC assay was performed by tracking activation kinetics of phospho-AKT and phospho-MAPK in Heregulin (HRG-≥1) stimulated cultured MDA-MB453 cells by Western Blotting and immunostaining of immediately paraformaldehyde-fixed cells. In addition, one-sided inhibition of PI3K/AKT and MAPK signaling cascades was performed using the MEK1-inhibitor PD98059 and the PI3K inhibitor LY294002. Xenograft tumors were used to define the acceptable cold ischemia time for complex tissues. Consistently, we found a narrow time window of &lt;10 minutes processing time (cold ischemia), in which AKT and MAPK phosphorylation could be accurately detected, where the pMAPK assay was more susceptible to time-dependent decrease in signal than the pAKT assay. In line with this, breast cancer samples obtained from immediately fixed fine needle punch biopsies (n=19) consistently showed strong staining for pMAPK and pAKT, while signals clearly decreased in the corresponding routinely processed surgical resection specimens. Knowing the appropriate processing conditions for multiplexed assessment, we studied pathway activation patterns in a series of invasive breast cancer (n=37) of commercially acquired samples, for which the provider (Indivumed, Hamburg, Germany) guarantees a cold ischemia time &lt;10 minutes and highly standardized, tightly controlled embedding process. 1/37 cases clearly showed predominant AKT activation, 2/37 cases had predominant MAPK activation, and 8/37 cases exhibited concomitant activation of both pathways throughout the tumor, indicating constitutive pathway activity. The remaining 26 cases showed a striking heterogeneity of pathway activation patterns, some with marked pMAPK signals at the interface of tumor to stromal/inflammatory cells, suggesting pathway activation in response to microenvironment interaction. Consistently, activated macrophages showed a strong pMAPK signal. The predominantly pAKT activated case was negative for PTEN by IHC and qRT-PCR. The pMAPK activated cases were ER/PR positive and HER2 negative.

In conclusion, duplex IHC for concomitant detection of pAKT and pMAPK can be robustly applied to immediately processed breast cancer fine needle biopsies, whereas the use in surgical resection specimens is likely to be inaccurate unless the material has been processed under tightly controlled conditions. The observed staining patterns suggest distinctive activation patterns pointing to genomic aberrations causing constitutive pathway activation. As tumor heterogeneity and inflammatory cells are likely to influence any pathway analysis on homogenized human breast cancer tissue, we recommend to consider morphological assessment to localize pathway activation to relevant cell populations.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-08-04.

High-dose methotrexate combined with procarbazine and CCNU for primary CNS lymphoma in the elderly: results of a prospective pilot and phase II study

BACKGROUND

To improve survival of elderly patients with primary central nervous system lymphoma (PCNSL), we conducted a phase II study with high-dose methotrexate (MTX) combined with procarbazine and CCNU. To reduce neurotoxicity, whole-brain irradiation was reserved for patients not responding to chemotherapy.

PATIENTS AND METHODS

High-dose MTX was applied on days 1, 15, and 30, procarbazine on days 1-10, and CCNU on day 1. Study treatment comprised up to three 45-day cycles. There was no lower limit of Karnofsky performance status (KPS).

RESULTS

Thirty patients with PCNSL (n = 29) or primary ocular lymphoma (n = 1) were included (median age 70 years, range 57-79 years). The median initial KPS was 60% (range 30%-90%). Best documented response in 27 assessable patients were 12 of 27 (44.4%) complete remissions, 7 of 27 (25.9%) partial remissions, and 8 of 27 (29.6%) disease progressions. Two patients died of probable treatment-related causes. With a median follow-up of 78 months (range 34-105), the 5-year overall survival is 33%. Eight of 30 patients (26.7%) are currently alive and well, six without signs of leukoencephalopathy.

CONCLUSION

The combination of high-dose MTX with procarbazine and CCNU is feasible and effective and results in a low rate of leukoencephalopathy. Comorbidity and toxicity remain of concern when treating PCNSL in elderly patients.

Primary CNS lymphoma in immunocompetent patients from 1989 to 2001: a retrospective analysis of 164 cases uniformly diagnosed by stereotactic biopsy

BACKGROUND

We present outcome data of a cohort of 164 immunocompetent PCNSL patients uniformly diagnosed at a single center for stereotactic neurosurgery, and evaluate the acceptance and impact of combination radiotherapy (RT) and chemotherapy (CHT) with high-dose methotrexate (HD-MTX) over time.

METHOD

We assessed choice of treatment and patient survival in a series of 164 PCNSL cases diagnosed from 1989 to 2001, and performed a re-evaluation of histopathology and pre-operative clinical data.

FINDINGS

From 1989 to 1993, RT was the predominant therapy, and additional CHT did not improve survival. After 1994, the use of combination CHT/RT increased continuously, consistently contained MTX, and was associated with longer survival than RT only: median survival was 14 months after CHT/RT (2-year survival 35.7%) and 10 months (2-year survival 26.2%) after RT only (not significant). Overall median survival remained poor, increasing from six (1989-1993) to nine months (1994-2001) (p = 0.008). Survival was variable, with a few patients surviving >4 years after diagnosis in the CHT/RT as well as in the RT only group.

CONCLUSIONS

Despite considerable improvement of PCNSL therapy, the overall benefit of combined CHT/RT versus RT only was lower than that expected from previous phase II clinical trials. The striking variability of survival in either treatment group may suggest a yet undefined biological heterogeneity of PCNSL, which may also include a more aggressive PCNSL subtype in the group of patients with rapidly progressive disease and not eligible for standard therapy.

Cell proliferation, apoptosis, and expression of Bcl-2 and Bax in non-lactating human breast epithelium in relation to the menstrual cycle and reproductive history

Cell proliferation, apoptosis, and the expression of Bcl-2 and Bax were investigated in breast tissue of healthy premenopausal women in order to study the effect of the menstrual cycle and reproductive history on the cell turnover in the non-lactating mammary gland epithelium. Immunohistochemistry was used to detect the proliferation-associated antigen Ki-67, as well as Bcl-2 and Bax. Apoptotic cells were identified by enzymatic labelling of fragmentized DNA (TUNEL-technique) and morphologic analysis. Consistent with published data, the proliferative activity and the frequency of apoptotic events as detected by morphologic analysis was higher in the luteal than in the follicular phase of the menstrual cycle. Parity, lactation, and age correlated with lower proliferative activity, whereas the frequency of apoptosis was not significantly influenced by the reproductive history. Staining patterns for Bax and Bcl-2 showed characteristic changes due to the menstrual cycle with a maximum of immunoreactivity for Bcl-2 in the follicular phase and for Bax in the luteal phase. However, there was no statistically significant association between Bcl-2/Bax immunoreactivity and menstrual cycle or reproductive parameters. We conclude that other molecular pathways than the Bax/Bcl-2 antagonism may additionally be involved in the regulation of apoptotic cell death in the breast epithelium. Knowledge of the entire complexity of apoptosis regulation is necessary to understand the observed effects of parity and lactation on mammary epithelial biology, and possibly to be able to influence pathological processes caused by an imbalance between cell renewal and elimination.

Reversible coma with raised intracranial pressure: an unusual clinical manifestation of CADASIL

A 50-year-old woman presented with recurrent episodes of headache, nausea and disturbed consciousness that were fully reversible within a few days. Clinical and radiological findings suggested raised intracranial pressure, which on one occasion was confirmed by intracranial pressure monitoring. Magnetic resonance imaging performed in the asymptomatic interval disclosed a diffuse leukoencephalopathy. Brain biopsy surprisingly revealed the typical vascular changes of CADASIL and subtle endothelial alterations. The white matter showed edematous changes and reactive gliosis. Mutational analysis of the Notch3 gene revealed a previously unreported mutation. We suggest that a transient disturbance of the blood-brain barrier related to the underlying vascular pathology may have caused this unusual presentation of CADASIL.

Lhermitte-Duclos disease: assessment with MR imaging, positron emission tomography, single-photon emission CT, and MR spectroscopy

SUMMARY

Lhermitte-Duclos disease (LDD) is a rare cerebellar lesion with features of both malformation and benign neoplasm. However, the fundamental nature of the entity, its pathogenesis, and the exact genetic alterations remain unknown. We describe MR findings (including perfusion- and diffusion-weighted images) in two patients with LDD, as well as findings from single-photon emission CT (SPECT), MR spectroscopy (MRS), and fluorodeoxyglucose (FDG) positron emission tomography (PET) that give additional information about tumor pathophysiology. MR imaging usually distinguishes the LDD by its characteristic "tiger-striped" appearance. The regions of increased regional cerebral blood volume (rCBV) within the lesion correlated closely to the regions of FDG-hypermetabolism and high thallium (201-Tl) uptake. Proton MRS revealed an increased level of lactate and decreased level of myo-inositiol and N-acetyl-aspartate, as observed in low-grade gliomas, but decreased levels of choline. Our cases indicate that the functional investigations give additional information about tumor pathophysiology and reflect the histopathologic controversial entity with both characteristics found in low-grade gliomas and characteristics not typical for tumors.

Cell turnover in apocrine metaplasia of the human mammary gland epithelium: apoptosis, proliferation, and immunohistochemical detection of Bcl-2, Bax, EGFR, and c-erbB2 gene products

Apocrine metaplasia is considered to be a benign lesion of human mammary epithelium. However, it is not known how apocrine differentiation develops, and whether there is a relationship with particular subtypes of mammary carcinoma. In order to investigate cell turnover in apocrine metaplasia, apoptosis was detected by terminal transferase nick-end-labelling, and Ki-67 was used as proliferation marker. Bcl-2, Bax, epidermal growth factor receptor (EGFR), and c-erbB2-encoded protein were detected by immunohistochemistry. The proliferative activity was low (<1%). Frequency and intraepithelial localization of apoptotic cells resembled those of normal mammary epithelium. Bax immunostaining was inconstant and weak, and Bcl-2 was not detectable in apocrine metaplasia. Immunoreactivity of the c-erbB2 gene product was membrane-bound and showed a moderate to strong intensity, whereas staining for EGFR was weak and inconsistent. When compared with normal breast epithelium, apocrine metaplasia shows a regular cell turnover at a low rate, although the expression patterns of regulatory proteins are clearly altered. Our data suggest that changes in the expression of Bcl-2 or c-erbB2 protein do not result in a significant imbalance of apoptosis and proliferation, and thus should not be interpreted as indicator for increased risk of neoplastic transformation.

Immunohistochemical analysis of Bcl-2 and Bax expression in relation to cell turnover and epithelial differentiation markers in the non-lactating human mammary gland epithelium

The expression of the apoptosis-related proteins Bcl-2 and Bax was investigated by immunohistochemistry in the normal non-lactating human mammary gland in relation to cell proliferation and apoptosis. In order to characterize individual Bax/Bcl-2-immunoreactive cells, the epithelial markers cytokeratin 14 and 19 and the macrophage marker CD 68 were used. Secretory-like differentiation of epithelial cells was characterized by histochemistry and lectin staining of surface glycoconjugates. Cell proliferation was exclusively found in glandular epithelial cells with broad contact to the ductular lumen, whereas nuclei with apoptosis-related DNA fragmentation were seen predominantly in basally located glandular epithelial cells and in myoepithelial cells. Weak immunoreactivity for Bcl-2 and Bax was present throughout all epithelia, suggesting a balance between pro- and antiapoptotic effects in the majority of epithelial cells. However, specific cells showed a strong staining for Bax or Bcl-2. The strongly Bcl-2-immunoreactive epithelial cells were not identical with proliferating cells, but they resembled them in configuration and in the luminal intraepithelial position. In contrast, the strongly Bax-positive epithelial cells had no or only a narrow contact to the ductular lumen. The different patterns of Bax/Bcl-2 immunoreactivity in specific glandular epithelial cells suggest that there are also different grades of susceptibility towards apoptotic stimuli in individual glandular epithelial cells. We conclude that specific Bax/Bcl-2 expression patterns could reflect particular cell differentiation states, and that the strongly Bcl-2-positive cells in part could represent epithelial stem cells.

Surfactant lipid uptake and metabolism by neonatal and adult type II pneumocytes

Animal experiments suggest developmental changes in surfactant homeostasis. The uptake and metabolism of [(3)H]dipalmitoylphosphatidylcholine-labeled liposomes with a surfactant-like composition were evaluated in type II cells isolated from rats of different postnatal ages. The early part of the uptake process (0-60 min) was more rapid and reached higher levels in cells from 2-day-old rats than in those from 7-day-old, 14-day-old, or adult rats. Temperature independence of this initial phase, differences in response to trypsin-EDTA or neuraminidase treatment, and the dependency of increased neonatal uptake on the presence of phosphatidylglycerol in liposomes suggested binding as a major mechanism of cell-lipid interaction. Although a two to three times larger amount of lipid was associated with neonatal cells, the metabolism of phosphatidylcholine, indicated by a decrease in label in phosphatidylcholine and an accompanying increase in sphingomyelin, was significantly smaller in 2-day-old than in adult cells. These studies support the hypothesis that neonatal and adult cells may have differences in the interaction with alveolar phospholipids and in the metabolism of phosphatidylcholine.

Histo- and cytophysiology of the lactating mammary gland of the African elephant (Loxodonta africana)

The lactating mammary gland of the African elephant (Loxodonta africana) has been studied with a panel of morphological techniques focusing on (1) the functional changes during the secretory process, (2) proliferative process [by application of proliferating cell nuclear antigen (PCNA) immunohistochemistry] and apoptotic phenomena [by use of the TUNEL technique] in the individual lobules, and (3) components of milk and milk-fat-globule membrane. In the lactating gland, the lobules are variably differentiated; within a lobule, however, the alveoli are usually similarly differentiated. The morphology of their alveoli suggests a classification of the lobules into types 1-3. Lobules of type 1 are composed of immature tubular alveoli with mitotic figures and numerous PCNA-positive nuclei; advanced type 1 alveoli contain abundant glycogen and specific secretory granules. Lobules of type 2 are further subdivided. In type 2a lobules, the epithelial cells of the alveoli form tall apical protrusions, which in part are occupied by small lipid droplets and which are pinched off in an apocrine fashion. The number of lysosomes varies considerably. Type 2b is the most common type, with striking basal membrane foldings, abundant rough endoplasmic reticulum cisterns, large Golgi apparatus, numerous mitochondria, lipid droplets, and protein vesicles with 30- to 90-nm-wide casein micelles. The lipid droplets are pinched off with minimal amounts of cytoplasm. Type 2c is composed of alveoli with a cuboidal epithelium and few signs of secretory activity. Increasing expression of peanut-agglutinin-binding sites parallels the maturation and differentiation of the glandular cells. Type 3 lobules are marked by numerous TUNEL-positive nuclei and large lipid droplets and are apparently degenerating structures. Cytokeratin (CK) 14 is usually present in the myoepithelial cells; CK 19 and CK 7 mark ductal and immature alveolar epithelia. Milk protein content varies between 2.6% and 6.3%, and casein micelles range from 35 to 90 nm in diameter. The diameter of intra-alveolar milk fat globules ranges from 5 to 25 micrometer and the membranes bear a filamentous surface coat composed of membrane-anchored mucins; gel-electrophoretic analysis of these mucins from different individuals demonstrates the presence of mucin MUC 1, which is expressed with considerable genetic heterogeneity.

[Immunohistologic study of the localization of ICAM-1 (intercellular cell adhesion molecule 1) in alveolar epithelium in the human lung]

The intercellular cell adhesion molecule 1 (ICAM-1) is expressed in the endothelium of pulmonary blood vessels, in the alveolar epithelium and in the bronchial epithelium. Because of conflicting reports in the literature on the question whether ICAM-1 is exclusively expressed in pneumocytes Type I or also in pneumocytes Type II, the present study aimed at characterising the cell types in normal human alveolar epithelium which show immunoreactivity for ICAM-1. Immunohistochemistry for ICAM-1 was performed on a series of 19 specimens of normal human lung. In addition, double staining procedures of ICAM-1 together with cell type specific antigens were performed. To detect pneumocytes Type II an antibody to cytokeratin 18 (CK 18) was used. Alveolar macrophages were marked by an antibody to the monocyte macrophage-specific leukocyte antigen CD 68. Vascular endothelium was stained by common endothelial markers (Ulex europaeus agglutinin Type I, anti-von Willebrand factor). The alveolar septa showed intense surface staining for ICAM-1 that could be localised predominantly to pneumocytes Type I. There were also single ICAM-1 positive cells having the characteristics of pneumocytes Type II in respect of their morphological appearance and their cytokeratin pattern. For the interpretation of these results the fact had to be considered that pneumocytes Type I can partly cover up pneumocytes Type II. This was confirmed by ultrastructural observations. Our findings suggest that ICAM-1 plays a part in the interaction between intraalveolar leukocytes and the alveolar epithelium.

Expression of inducible cell adhesion molecules in the normal human lung: immunohistochemical study of their distribution in pulmonary blood vessels

The distribution of cell adhesion molecules in the normal human lung was investigated using antibodies to E-selectin, P-selectin, intercellular adhesion molecule 1(ICAM-1), and vascular cell adhesion molecule 1 (VCAM-1). Lectin staining by Ulex europaeus type I agglutinin (UEA I) and immunohistochemistry for von Willebrand factor (vWF) was used to visualize a maximum of blood vessels per section. In the bronchial mucosa, staining for P-selectin was positive in ca 90%, and staining for E-selectin, VCAM-1, and ICAM-1 was positive in 40-70% of the vessels stained with UEA I. In the pulmonary circulation (vasa publica) ca 90% of non-capillary vessels stained by anti-vWF expressed P-selectin, 54% VCAM-1, 41% E-selectin, and only ca 20% ICAM 1. The alveolar capillaries were stained consistently by UEA I, but not by the panel of antibodies tested. The alveolar epithelium and, inconstantly, basal cells of the bronchial epithelium were positive for ICAM-1. The distribution pattern of inducible adhesion molecules in normal human lung tissue suggests that a permanent low-grade endothelial activation may exist in particular in the mucosa of the airways, which could be due to the normal antigen exposure via inhaled air.

Cutaneous glands of male and female impalas (Aepyceros melampus): seasonal activity changes and secretory mechanisms

The cutaneous glands of the forehead and the metatarsus were studied by histological and histochemical methods and electron microscopy in adult male and female impalas in various seasons of the year. All glandular areas consist of apocrine and holocrine glands, which, however, occur in different proportions. Our findings in the apocrine gland cells suggest (1) the synthesis and exocytosis of a glycoproteinaceous secretory product stored in secretory granules, (2) typical apocrine secretion of the transformed apical cytoplasm, and (3) transepithelial fluid transport. The Golgi apparatus and apical membrane have binding sites for several lectins (PNA, HPA, RCA I, WGA). Cytokeratins 7, 14 and 19 are expressed at various intracellular localizations, suggesting an active role in the secretory mechanisms. The glands of the male forehead show marked seasonal changes in activity that are correlated with the main phases of the reproductive cycle, with the highest cellular activity occurring during the rut in April/May. The female forehead glands are only moderately developed and do not undergo seasonal changes. The metatarsal glands are of equal size in males and females and show no seasonal changes in activity. This study supports the hypothesis that (1) forehead glands in the male have a signaling role in the rut and (2) the metatarsal glands have a more general, probably social role maintaining and restoring contact between herd members.