Six-year follow-up of patients with microinvasive, T1a, and T1b breast carcinoma

BACKGROUND

Management of patients with breast cancers < or = 1 cm remains controversial. Reports of infrequent nodal metastases in tumors < or = 5 mm has led to suggestions that axillary dissection should be selective, and that tumor characteristics should guide adjuvant therapy.

METHODS

A retrospective review of 290 patients with breast cancer 1 cm in size or smaller from 1989 to 1991 was done. Distant disease-free survival (DDFS) was the primary outcome measure.

RESULTS

There were 95 T1a (< or = 5 mm) and 196 T1b (6-10 mm) cancers. Nodal metastases were found in 8 T1a and 26 T1b tumors. Larger size, poorer differentiation, and lymphovascular invasion (LVI) were associated with more nodal metastases, but none of these trends reached statistical significance. The 6-year DDFS was 93% for node-negative and 87% for node-positive patients (P = .02). Overall, breast cancers with poorer differentiation and LVI trended toward a poorer outcome. For patients with node-negative tumors, LVI was associated with a poorer outcome (P = .03). The size of the primary tumor was not predictive of outcome. There were no nodal metastases or recurrences in the 18 patients with microinvasive breast cancer.

CONCLUSIONS

Lymph node status is the major determinant of outcome in breast cancers 1 cm in size or smaller. Accurate axillary assessment remains crucial in management of small breast cancer.

Volume of resection in patients treated with breast conservation for ductal carcinoma in situ

BACKGROUND

The optimal treatment of ductal carcinoma in situ (DCIS) is one of the most controversial issues in the management of breast cancer. Identification of factors that affect the risk of local recurrence is very important as the incidence of DCIS increases and the use of breast conservation becomes more widespread. Because the extent of resection may affect the relapse rate, we hypothesized that larger volumes of resection (VR) may account for the lower local recurrence rates we have previously found in elderly patients.

METHODS

Between 1978 and 1990, 173 cases of histologically confirmed DCIS were treated at MSKCC with breast conservation therapy. Of these, complete VR data were available for 126 cases. The VRs thus obtained were divided into two groups, <60 cm3 and > or =60 cm3, and were evaluated for correlating factors. The patients were divided into three groups by age at diagnosis: younger than 40 years, 40 to 69 years, and 70 years or older.

RESULTS

The eldest group had a significantly greater proportion of large VRs (30%) as compared to the middle group (11%) and the youngest group (9%) (P=.03, chi2). Although not statistically significant, the large VR group had a lower 6-year actuarial local recurrence rate (5.6%) than did the small VR group (21.3%) (P=.16, log-rank test). This trend was observed even though adjuvant radiotherapy was used less often in patients who had large VRs.

CONCLUSION

Breast conservation surgery for DCIS in elderly patients is more likely to employ a large VR. This may explain, at least in part, the observation that elderly patients have a lower local recurrence rate.

Patient regrets after bilateral prophylactic mastectomy

BACKGROUND

The discovery of a cadre of breast cancer susceptibility genes has resulted in an increase in the number of women seeking information about prophylactic breast surgery, but virtually no large-scale prospective databases exist to assist women considering prophylactic mastectomy.

METHODS

The authors constructed a National Prophylactic Mastectomy Registry comprised of a volunteer population of 817 women from 43 states who have undergone prophylactic mastectomy.

RESULTS

In the registry, 370 women had undergone bilateral prophylactic mastectomy. Twenty-one (5%) women expressed regrets about the procedure. The median follow-up was 14.6 years (mean 14.8 years; range 0.2-51 years). Those with regrets were subsetted into those with major (n = 10) or minor (n = 7) regrets. Regrets were more common in those women with whom discussion about prophylactic mastectomy was initiated by a physician (19/255), compared with patients who initiated the discussion themselves (2/108; P < .05).

CONCLUSIONS

The overall satisfaction rate of 95% reported here may be explained by the voluntary nature of this registry. The most important factor that predicts an unfavorable outcome following bilateral prophylactic mastectomy is a physician-initiated discussion.

Hypomethylation and increased gene expression of p16INK4a in primary and metastatic breast carcinoma as compared to normal breast tissue

Controversy continues to surround the role of p16INK4a in cell cycle control and carcinogenesis. Mutations, deletions and changes in methylation patterns of p16INK4a have been proposed as mechanisms leading to abnormal expression of the gene. We show here that primary and metastatic breast carcinomas demonstrate hypomethylation of p16INK4a which is associated with expression of p16INK4a mRNA, as compared to normal breast tissue which demonstrates a relative hypermethylation of p16INK4a associated with the absence of p16INK4a expression. These data suggest that methylation and lack of expression of p16INK4a is not a central mechanism in the development of breast carcinoma, but rather that the gene is functioning and expressed in breast carcinoma more frequently than in normal breast tissue. The role of p16INK4a is much more complex than has been previously hypothesized.

Preoperative galactography increases the diagnostic yield of major duct excision for nipple discharge

BACKGROUND

Although most nipple discharge is due to a benign etiology, approximately 10-15% is due to breast carcinoma. The standard management of nipple discharge includes major duct excision, and although this procedure may eliminate future nipple discharge, a specific etiology is not always found. This study investigates the utility of preoperative galactography in targeting the causative lesion.

METHODS

During 1994-1996, 46 cases of major duct excision were identified from operating room records. All patients presented with spontaneous nipple discharge from a single duct. In 16 patients both a diagnostic galactogram and a preoperative galactogram with methylene blue were performed to localize the causative lesion and to enable intraoperative identification. Data were obtained by retrospective chart review. Statistical significance was determined by Fisher's exact test.

RESULTS

Preoperative galactography was obtained in 7 of 31 patients (23%) with bloody nipple discharge and 9 of 15 patients (60%) with guaiac negative discharge. All patients undergoing preoperative galactography were found to have either a filling defect and/or duct cutoff (n = 13) or duct ectasia (n = 3). All patients with a filling defect and/or duct cutoff on galactogram were found to have a carcinoma or papilloma at surgery. In the three patients with duct ectasia observed on galactogram, the diagnosis was confirmed at surgery. All patients who underwent preoperative galactography were found to have specific pathology that accounted for the nipple discharge versus 20 of 30 patients (67%) who did not undergo preoperative galactography (P = 0.009).

CONCLUSIONS

Although major duct excision for nipple discharge may eliminate the presenting symptomatology, a pathologic correlate is not always found. The data from the current study show that localizing the causative lesion by preoperative galactography increases the likelihood that specific pathology will be found at surgery, and suggests that preoperative galactography may be helpful in the evaluation and management of patients presenting with spontaneous nipple discharge. Cancer 1998;82:1874-80. 1998 American Cancer Society.

Incidence of axillary lymph node metastases in T1a and T1b breast carcinoma

BACKGROUND

We investigated the incidence of axillary lymph node metastases in patients with T1a (< or = 0.5 cm) and T1b (> 0.5 cm and < or = 1.0 cm) breast cancers.

METHODS

The charts of 2000 patients who underwent axillary lymph node dissection for breast cancer at our institution from 1989 to 1991 were reviewed. Of these, 81 patients had T1a and 166 had T1b primary breast cancers.

RESULTS

Among the 247 patients with T1a and T1b breast cancers, nodal metastases were present in 30 (12.1%), with a 7.4% positivity rate for patients with T1a and 14.5% positivity rate for T1b tumors. Of the 212 patients who had > or = 10 nodes dissected, 29 (13.7%) had positive nodes. Of those, 6 of 60 (10.0%) patients with T1a and 23 of 152 (15.1%) with T1b tumors had positive nodes. The presence of lymphovascular invasion (LVI) predicted a significantly higher nodal positivity rate (27.8% vs. 10.9%, p = 0.05).

CONCLUSIONS

Of patients with adequately evaluated axillae, 10% with T1a and 15% with T1b cancers were found to have nodal metastases. Although LVI was significantly associated with a higher risk of lymph node metastases, we could not characterize any subgroup at acceptably low risk of nodal positivity. Until a more useful prognostic indicator is discovered, axillary dissection should continue to be part of the mainstay of management for small breast cancers.

The Special Surveillance Breast Program: a model of intervention for women at high risk for breast cancer

The Special Surveillance Breast Program (SSBP) is a long-term, comprehensive, multidisciplinary program for women determined to be at high risk for the development of breast cancer. Because the women who attend this program are otherwise healthy but concerned about their risk for breast cancer, current and relevant information is required to address their concerns regarding the possibility of developing breast cancer. The purpose of this article is to describe the risk factors that indicate eligibility for the program, the structure of the program, and the results of an assessment that identified the needs of this special population.

Pretreatment with a 55-kDa tumor necrosis factor receptor-immunoglobulin fusion protein attenuates activation of coagulation, but not of fibrinolysis, during lethal bacteremia in baboons

Baboons (Papio anubis) receiving a lethal intravenous infusion with live Escherichia coli were pretreated with either a 55-kDa tumor necrosis factor (TNF) receptor-IgG fusion protein (TNFR55:IgG) (n = 4, 4.6 mg/kg) or placebo (n = 4). Neutralization of TNF activity in TNFR55:IgG-treated animals was associated with a complete prevention of mortality and a strong attenuation of coagulation activation as reflected by the plasma concentrations of thrombin-antithrombin III complexes (P < .05). Activation of fibrinolysis was not influenced by TNFR55:IgG (plasma tissue-type plasminogen activator and plasmin-alpha2-antiplasmin complexes), whereas TNFR55:IgG did inhibit the release of plasminogen activator inhibitor type I (P < .05). Furthermore, TNFR55:IgG inhibited neutrophil degranulation (plasma levels of elastase-alpha1-antitrypsin complexes, P < .05) and modestly reduced release of secretory phospholipase A2. These data suggest that endogenous TNF contributes to activation of coagulation, but not to stimulation of fibrinolysis, during severe bacteremia.

Absence of p16 gene (CDKN2) deletions in microdissected primary breast carcinoma specimens

BACKGROUND

The p16 gene (CDKN2), a tumor suppressor gene located on chromosome 9p21, has been demonstrated to be mutated or deleted with high frequency in a variety of tumor cell lines, including breast. While previous studies have not demonstrated CDKN2 mutations in primary breast carcinomas, it is possible that gene deletion in neoplastic DNA was marked by the presence of contaminating normal stromal DNA in breast carcinoma specimens.

METHODS

We investigated the incidence of homozygous deletion of CDKN2 by analyzing 20 microdissected pure populations of primary breast carcinoma cells. Using polymerase chain reaction (PCR) techniques, the entire coding region and intervening introns of CDKN2 were amplified. The PCR products were resolved by agarose gel electrophoresis and single-strand conformation polymorphism (SSCP) analysis.

RESULTS

We detected no deletions or mutations of the p16 gene.

CONCLUSIONS

CDKN2 is not deleted with high frequency in primary breast carcinomas, and the p16 gene does not play a role in breast carcinogenesis via this mechanism.

Stereotactic core biopsy of calcifications highly suggestive of malignancy

PURPOSE

To assess stereotactic core biopsy for evaluation of Breast Imaging Reporting and Data System (BI-RADS) category 5 calcifications (highly suggestive of malignancy).

MATERIALS AND METHODS

Retrospective review of mammograms revealed 31 women (aged 34-86 years) with BI-RADS category 5 calcifications who underwent 14-gauge stereotactic core biopsy with an automated gun. Records were reviewed to determine the frequency with which stereotactic core biopsy obviated a surgical procedure. Cost savings were based on Medicare estimates of $472 for stereotactic core biopsy and $1,335 for surgical biopsy.

RESULTS

Of 31 patients, stereotactic core biopsy revealed carcinoma in 19 (61%), atypical ductal hyperplasia (ADH) in eight (26%), and benign findings discordant with mammographic results in four (13%). Surgical biopsy was recommended for the 12 patients with ADH or benign but discordant core biopsy diagnoses. Of the 19 patients with carcinoma at stereotactic core biopsy, two chose to undergo a second biopsy surgically, two had small foci of ductal carcinoma in situ (DCIS) that would have been fully excised with surgical biopsy, one with DCIS at stereotactic core biopsy underwent axillary dissection after invasion was found at surgery, and one underwent excision but had tumor at lumpectomy margins. Thirteen (42%) of 31 patients were spared a surgical procedure, saving $100 per patient.

CONCLUSION

Stereotactic core biopsy with an automated gun obviated a surgical procedure in 42% of patients with BI-RADS category 5 calcifications, resulting in modest cost savings in this group.

Mammographic features of local recurrence in women who have undergone breast-conserving therapy for ductal carcinoma in situ

OBJECTIVE

This study was undertaken to evaluate the mammographic features of local recurrence in women who have undergone breast-conserving therapy for ductal carcinoma in situ (DCIS).

MATERIALS AND METHODS

Retrospective review revealed 162 women with DCIS treated with breast-conserving therapy from 1978 to 1990 for whom follow-up data were available. Subsequent to therapy, 33 (20%) patients had a pathologically proven carcinoma in the treated breast. Mammograms at the time of local recurrence were available for 20 patients. We reviewed mammograms, clinical charts, and histopathologic findings in these 20 patients. For 14 of 20 patients, we also reviewed mammograms obtained at the time of the original DCIS.

RESULTS

The median interval from diagnosis of the original DCIS to local recurrence was 26 months (range, 6-168 months). Recurrences were detected solely by mammography in 17 (85%) of 20 patients, by mammography and physical examination in two (10%), and solely by physical examination in one (5%). Eighteen (90%) local recurrence contained calcifications and eighteen (90%) involved the tumorectomy quadrant. When we compared available mammographic findings of the original DCIS and the local recurrence we found the mammographic pattern and calcification morphology to be the same in 11 (79%) of 14 DCIS and nine (82%) of 11 DCIS, respectively. Histopathologic analysis of recurrences found DCIS in 13 (65%) of 20 patients and DCIS and infiltrating carcinoma in the remaining seven (35%) patients. Of 13 pure DCIS recurrences, 12 (92%) were detected solely by mammography.

CONCLUSION

In our study, local recurrence after breast-conserving therapy for DCIS invariably contained DCIS; 35% of recurrences also contained invasive carcinoma. The most common mammographic pattern of local recurrence was calcifications in the tumorectomy quadrant that were morphologically similar to the original DCIS. These findings suggest that many of these local recurrences reflect failure to eradicate the primary DCIS. Mammography achieved high sensitivity in revealing these lesions: 85% of local recurrences and 92% of recurrences that were pure DCIS were detected solely by mammography.

Tumor necrosis factor-alpha induces activation of coagulation and fibrinolysis in baboons through an exclusive effect on the p55 receptor

Tumor necrosis factor-alpha (TNF-alpha) can bind to two distinct transmembrane receptors, the p55 and p75 TNF receptors. We compared the capability of two mutant TNF proteins with exclusive affinity for the p55 or p75 TNF receptor with that of wild type TNF, to activate the hemostatic mechanism in baboons. Both activation of the coagulation system, monitored by the plasma levels of thrombin-antithrombin III complexes, and activation of the fibrinolytic system (plasma levels of tissue-type plasminogen activator, and plasminogen activator inhibitor type I), were of similar magnitude after intravenous injection of wild type TNF or the TNF mutant with affinity only for the p55 receptor. Likewise, wild type TNF and the TNF p55 specific mutant were equally potent in inducing neutrophil degranulation (plasma levels of elastase-alpha 1-antitrypsin complexes). Wild type TNF tended to be a more potent inducer of secretory phospholipase A2 release than the p55 specific TNF mutant. Administration of the TNF mutant binding only to the p75 receptor did not induce any of these responses. We conclude that TNF-Induced stimulation of coagulation, fibrinolysis, neutrophil degranulation, and release of secretory phospholipase A2 are predominantly mediated by the p55 TNF receptor.

Protection against lethal Escherichia coli bacteremia in baboons (Papio anubis) by pretreatment with a 55-kDa TNF receptor (CD120a)-Ig fusion protein, Ro 45-2081

Fusion proteins of the human 55-kDa TNF receptor extracellular domain with hinge and C2/C3 constant domains of human IgG1 or IgG3 heavy chains were tested in a primate sepsis model. Twenty-four baboons received 4.6, or 0.2 mg/kg of TNFR5-G1,3, or placebo, before the administration of a lethal dose of live Escherichia coli. Treatment with TNFR5-G1,3 decreased 5-day mortality from 88% in the placebo group to 12% in the TNFR5-G1,3-treated animals (p &lt; 0.01 by Fisher's exact test). Treatments with TNR5-G1 and TNFR5-G3 in doses from 0.2 to 4.6 mg/kg were efficacious. Free plasma TNF was neutralized by all treatments, but inactive TNF/TNFR5-G1,3 complexes remained in circulation for prolonged periods. TNFR5-1,3 treatments attenuated the hemodynamic disturbances, reduced fluid requirements, and decreased the systemic IL-1 beta, IL-6, and IL-8 responses. In addition, TNFR5-G1,3 treatment shortened the granulocytopenia and reduced the loss of cellular TNF receptors from granulocytes. The decrease in fibrinogen concentrations and increase in prothrombin and partial thromboplastin times were significantly attenuated by TNFR5-G1,3 treatment. TNFR5-G1,3 treatment markedly attenuated the rise in plasma lactate concentration. Histologic studies of TNFR5-G1,3 revealed dose-dependent protection against tissue injury by Escherichia coli administration.

Protection against lethal Escherichia coli bacteremia in baboons (Papio anubis) by pretreatment with a 55-kDa TNF receptor (CD120a)-Ig fusion protein, Ro 45-2081

Fusion proteins of the human 55-kDa TNF receptor extracellular domain with hinge and C2/C3 constant domains of human IgG1 or IgG3 heavy chains were tested in a primate sepsis model. Twenty-four baboons received 4.6, or 0.2 mg/kg of TNFR5-G1,3, or placebo, before the administration of a lethal dose of live Escherichia coli. Treatment with TNFR5-G1,3 decreased 5-day mortality from 88% in the placebo group to 12% in the TNFR5-G1,3-treated animals (p < 0.01 by Fisher's exact test). Treatments with TNR5-G1 and TNFR5-G3 in doses from 0.2 to 4.6 mg/kg were efficacious. Free plasma TNF was neutralized by all treatments, but inactive TNF/TNFR5-G1,3 complexes remained in circulation for prolonged periods. TNFR5-1,3 treatments attenuated the hemodynamic disturbances, reduced fluid requirements, and decreased the systemic IL-1 beta, IL-6, and IL-8 responses. In addition, TNFR5-G1,3 treatment shortened the granulocytopenia and reduced the loss of cellular TNF receptors from granulocytes. The decrease in fibrinogen concentrations and increase in prothrombin and partial thromboplastin times were significantly attenuated by TNFR5-G1,3 treatment. TNFR5-G1,3 treatment markedly attenuated the rise in plasma lactate concentration. Histologic studies of TNFR5-G1,3 revealed dose-dependent protection against tissue injury by Escherichia coli administration.

Microdissection and molecular genetic analysis of HER2/neu in breast carcinoma

Precise correlation of histomorphology with molecular genetic analysis is difficult in tissues composed of heterogeneous cell populations. We describe here a novel microdissection technique employed to correlate HER2/neu (HER2) immunohistochemical staining with HER2 genetic analysis in formalin-fixed, paraffin-embedded breast tissue. Fourteen invasive ductal carcinomas were selected from the pathology files of Memorial Sloan-Kettering Cancer Center that had been immunostained for HER2. Seven tumors showed typical membrane immunoreactivity and seven were negative. A dissecting microscope was then used to isolate minute (< or = 1 mm x 1 mm) areas of invasive carcinoma and normal breast tissue for molecular study. To document the type of cell sample submitted for polymerase chain reaction (PCR) analysis, each microdissected piece of tissue was photographed prior to removal from the glass slide. A preliminary study of four cases compared the results of PCR and genetic analysis using microdissected hematoxylin and eosin (H & E)-stained tissue, unstained dewaxed tissue, and destained dewaxed tissue in four specimens. Similar results were obtained with all three tissue preparations. Thereafter, H & E stained sections were selected as the tissue preparation of choice because tissue details were seen more clearly. There was complete correlation of immunohistochemical staining and HER2 analysis by PCR in all 14 cases. In the final 10 cases, the PCR product was resolved by gel electrophoresis and quantified by optical densitometry. Fourfold to eightfold amplification of HER2 was found in the five tumor specimens that immunohistochemically stained for HER2. A single copy of HER2 was found in all HER2-negative tumors and in normal breast tissue. We conclude that it is possible to quantify gene amplification of HER2 in minute samples of H & E-stained normal and malignant breast tissue. This microdissection technique can be applied to correlative histologic--molecular genetic analysis in a wide variety of tumor types.

Interleukin-1 contributes to increased concentrations of soluble tumor necrosis factor receptor type I in sepsis

Studies were done in baboons and humans to assess the role of interleukin (IL)-1 on the release of soluble tumor necrosis factor receptors (sTNFRs) during sepsis. In baboons, IL-1 alpha induced increased levels of sTNFR types I and II. Infusion of Escherichia coli into baboons also led to higher sTNFR levels. Treatment with IL-1 receptor antagonist (ra) attenuated the rise in sTNFR-I, which was positively correlated with a partial preservation of renal function by IL-1ra. In patients with sepsis, treatment with IL-1ra also was associated with lower levels of sTNFR-1 but did not influence plasma creatinine levels. IL-1ra did not affect sTNFR-II in baboons or humans. These data suggest that IL-1 produced during sepsis is involved in increases in sTNFR-I. Such increases during rapidly fatal septic shock may in part be explained by an effect on the renal clearance of sTNFR-I.

Interleukin-1 receptor blockade does not affect endotoxin-induced changes in plasma thyroid hormone and thyrotropin concentrations in man

Interleukin-1 (IL-1) has been implicated as a mediator of the euthyroid sick syndrome. The effects of IL-1 can be blocked by the naturally occurring IL-1 receptor antagonist (IL-1ra). In the present study, iv administration of endotoxin was used as a human model of the euthyroid sick syndrome. To assess the role of endogenous IL-1 in endotoxin-induced changes in plasma thyroid hormone and TSH concentrations, 18 healthy postabsorptive humans were studied on a control study day, followed 3 days later by a study day on which they were randomly assigned to one of three treatments: a 6-h infusion of recombinant human IL-1ra alone (133 mg/h), endotoxin alone (lot EC-5; 20 U/kg), or both endotoxin and IL-1ra. Administration of IL-1ra alone did not affect the plasma concentrations of thyroid hormones or TSH compared with those on the control day. Endotoxin injection was associated with decreases in T4 (P = 0.06 vs. the control day), free T4 (P = 0.02), T3 (P < 0.001), and TSH (P < 0.0001) and a rise in rT3 (P < 0.001), reproducing the major features of the euthyroid sick syndrome. Coinfusion of IL-1ra did not influence these endotoxin-induced changes. Our results suggest that endogenous IL-1 does not play an important role in the alterations in plasma thyroid hormone and TSH concentrations induced by mild endotoxemia in healthy humans.

Influence of IL-1 receptor blockade on the human response to endotoxemia

Although the experimental administration of IL-1 induces several aspects of the inflammatory response, such as fever, tachycardia, and acute phase proteinemia, the contribution of IL-1 to the human responses to injury or infection remains unclear. A specific IL-1R antagonist (IL-1ra), which effectively blocks the actions of IL-1, was utilized to evaluate the influence of endogenous IL-1 during experimental human endotoxemia. Eighteen healthy volunteers each underwent one control study day, followed 3 days later by one of three randomly chosen treatments: a 6-h infusion of IL-1ra alone (133 mg/h), 20 U/kg national reference endotoxin alone, or both endotoxin and IL-1ra infusion. IL-1ra administration alone was not associated with any observable response. Despite achieving high circulating levels of IL-1ra (34 +/- 3 micrograms/ml), there were no significant differences in hemodynamic parameters, core temperature, or resting energy expenditure in those endotoxemic volunteers receiving IL-1ra when compared with those who did not. Furthermore, leukocyte kinetic and circulating cytokine, acute phase protein, and endocrine responses were similar in both endotoxemic groups. However, IL-1 blockade did significantly reduce the subjective severity of symptoms experienced by the endotoxemic volunteers (p < 0.05). This study demonstrates that an endogenous IL-1 response does not play a significant role in the hemodynamic, immunologic, and metabolic responses to mild endotoxemia in humans.

Influence of IL-1 receptor blockade on the human response to endotoxemia

Although the experimental administration of IL-1 induces several aspects of the inflammatory response, such as fever, tachycardia, and acute phase proteinemia, the contribution of IL-1 to the human responses to injury or infection remains unclear. A specific IL-1R antagonist (IL-1ra), which effectively blocks the actions of IL-1, was utilized to evaluate the influence of endogenous IL-1 during experimental human endotoxemia. Eighteen healthy volunteers each underwent one control study day, followed 3 days later by one of three randomly chosen treatments: a 6-h infusion of IL-1ra alone (133 mg/h), 20 U/kg national reference endotoxin alone, or both endotoxin and IL-1ra infusion. IL-1ra administration alone was not associated with any observable response. Despite achieving high circulating levels of IL-1ra (34 +/- 3 micrograms/ml), there were no significant differences in hemodynamic parameters, core temperature, or resting energy expenditure in those endotoxemic volunteers receiving IL-1ra when compared with those who did not. Furthermore, leukocyte kinetic and circulating cytokine, acute phase protein, and endocrine responses were similar in both endotoxemic groups. However, IL-1 blockade did significantly reduce the subjective severity of symptoms experienced by the endotoxemic volunteers (p &lt; 0.05). This study demonstrates that an endogenous IL-1 response does not play a significant role in the hemodynamic, immunologic, and metabolic responses to mild endotoxemia in humans.

A human tumor necrosis factor (TNF) alpha mutant that binds exclusively to the p55 TNF receptor produces toxicity in the baboon

A number of recent studies have demonstrated that cellular responses to tumor necrosis factor (TNF) mediated by the p55 and the p75 TNF receptors are distinct. To evaluate the relative in vivo toxicities of wild-type TNF alpha (wtTNF alpha) and a novel p55 TNF selective receptor agonist, healthy, anesthetized baboons (Papio sp.) were infused with a near-lethal dose of either wtTNF alpha or a TNF alpha double mutant (dmTNF alpha) that binds specifically to the p55, but not to the p75, TNF receptor. Both wtTNF alpha and dmTNF alpha produced comparable acute hypotension, tachycardia, increased plasma lactate, and organ dysfunction in Papio. However, administration of wtTNF alpha produced a marked granulocytosis and loss of granulocyte TNF receptors, whereas little if any changes in neutrophil number or cell surface TNF receptor density were seen after dmTNF alpha mutant administration. Infusion of dmTNF alpha resulted in a plasma endogenous TNF alpha response that peaked after 90-120 min. We conclude that selective p55 TNF receptor activation is associated with early hemodynamic changes and the autocrine release of endogenous TNF alpha. Significant systemic toxicity results from p55 TNF receptor activation, but the role of the p75 TNF receptor in systemic TNF toxicity requires further study.

The role of bactericidal/permeability-increasing protein in the treatment of primate bacteremia and septic shock

Human neutrophil azurophilic granules contain an approximately 55-kDa protein, known as bactericidal/permeability-increasing protein (BPI), which possesses a high-affinity binding domain for the lipid A component of lipopolysaccharide (LPS). The in vivo LPS neutralizing activity of exogenous BPI was studied in a model of lethal Escherichia coli bacteremia. Five baboons were treated with BPI (5 mg/kg bolus injection followed by a 95 micrograms/kg/min BPI infusion over 4 hr), while four additional animals received a genetically engineered variant of BPI (NCY103). Five animals received a placebo treatment and served as controls. Both wild-type rhBPI and NCY103 significantly (P < 0.05) decreased blood levels of LPS throughout an 8-hr evaluation period following live bacterial challenge. Two hours following E. coli administration, LPS levels peaked in the controls, at 6.86 +/- 3.22 ng/ml, whereas LPS levels were 3.39 +/- 2.1 ng/ml in the BPI group and 2.04 +/- 1.18 ng/ml in the NCY103 group. Tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 levels likewise were attenuated in the treatment groups, whereas circulating sTNFR I was significantly (P < 0.05) reduced only in the BPI group. Leukocytopenia and granulocytopenia were significantly (P < 0.02) lessened in the BPI group, by an average of 59% leukocytopenia and 65% granulocytopenia, respectively. This study supports the concept of E. coli LPS neutralization by BPI in vivo and demonstrates that a moderate (70%) reduction in peak LPS-LAL activity is sufficient to alter some hematologic and cytokine manifestations of bacteremia.

Persistently elevated soluble tumor necrosis factor receptor and interleukin-1 receptor antagonist levels in critically ill patients

The appearance of endogenously produced inhibitors against tumor necrosis factor (TNF) (soluble TNF-receptor type I, sTNFR-I) and interleukin-1 (IL-1 receptor antagonist, IL-1ra) was evaluated acutely in five normal patients after experimental endotoxemia lipopolysaccharide (LPS) and prospectively during a one to 11 week period in 12 septic, critically ill patients. Increased levels of both factors remained detectable in the circulation for up to 24 hours after LPS (2 nanograms per kilogram body weight) administration in normal patients. Despite free TNF-a activity being detected only sporadically (3 percent of the samples) and that IL-1 beta was never detectable in the patients in the intensive care unit, IL-6 bioactivity was present in 90 percent of initial samples. Circulating sTNFR-I levels up to 62,000 picograms per milliliter and IL-1ra levels of 14,800 picograms per milliliter were noted in the critically ill patients and remained consistently detectable throughout the extended period of evaluation. While there was no difference in IL-1ra levels between patients who survived or ultimately died, sTNFR-I levels were significantly (p < 0.001) lower in survivors compared with nonsurvivors. A correlation between circulating sTNFR-I and concurrent cortisol levels (r = 0.64; p < 0.002) was also noted. Furthermore, a correlation between sTNFR-I and the severity of initial insult, as assessed by APACHE II scores (r = 0.54; p < 0.01) was demonstrable. These naturally occurring cytokine antagonists likely represent additional indicators of the presence of an infectious or other inflammatory process and seem to persist in the circulation even during conditions in which their respective proinflammatory cytokines are not demonstrable.

Cachexia and the acute-phase protein response in inflammation are regulated by interleukin-6

Cachexia and the acute-phase response are common manifestations of inflammation and are presumed to be the product of increased synthesis and release of cytokines, including tumor necrosis factor (TNF), interleukin-1 (IL-1) and interleukin-6 (IL-6). IL-1 receptor blockade has been previously shown to attenuate the weight loss, anorexia and acute-phase protein responses associated with a turpentine abscess. However, IL-1 receptor blockade was also associated with a reduced plasma IL-6 response, suggesting that the benefit achieved by IL-1 receptor blockade may be mediated by reduced systemic IL-6 production. To gain a better understanding of the role of IL-6 in this model of inflammation, C57BL/6 mice were passively immunized with either a monoclonal anti-IL-6 antibody (20F3), an anti-IL-1 type I receptor monoclonal antibody (35F5), a non-immune rat IgG, or a combined therapy of 35F5 and 20F3, before receiving a sterile turpentine abscess. IL-6 or IL-1 receptor blockade equally spared body weight and food intake. Compared to IL-1 receptor blockade, passive immunization against IL-6 further reduced the hepatic acute-phase protein response, as represented by serum amyloid P and complement 3. Combined blockade of IL-6 and IL-1 receptor did not result in a further sparing of body weights or improvement of food intake. These results confirm that IL-1 contributes to host cachexia and the acute-phase response following a turpentine abscess, but also show that these actions are dependent upon an IL-6 response. We conclude that the influence of IL-1 on cachexia and the acute-phase response is mediated, at least in part, through IL-6 and, thus, IL-6 may play a pivotal role in the cachexia and acute-phase response to inflammation.

Comparison of peripheral blood leukocyte kinetics after live Escherichia coli, endotoxin, or interleukin-1 alpha administration. Studies using a novel interleukin-1 receptor antagonist

OBJECTIVE

This study was undertaken to evaluate whether hematologic and immunologic effects observed after bacteremia and endotoxemia in the host could be replicated by administration of recombinant human interleukin-1 alpha (IL-1 alpha) in a primate model. Furthermore, to determine whether endogenously produced interleukin-1 (IL-1) contributes to the changes observed during endotoxemia or gram-negative septic shock, a specific IL-1 receptor antagonist (IL-1 ra) was administered.

SUMMARY BACKGROUND DATA

The lipopolysaccharide (LPS) component of the outer membrane of gram-negative bacteria initiates a constellation of metabolic and immunologic host responses. IL-1, a macrophage-derived cytokine, acts as a key mediator in the host response to infection and inflammation.

METHODS

Baboons were randomly assigned to receive either recombinant human IL-1 alpha, LPS, or live Escherichia coli both with or without concomitant administration of IL-1ra. Blood was collected hourly and analyzed using flow cytometric techniques.

RESULTS

Both endotoxemia and live E. coli bacteremia induced an acute granulocytopenia; however, the granulocytopenia gradually resolved in the endotoxemic group, but was sustained in the bacteremic group. An early lymphopenia and monocytopenia was elicited by LPS or E. coli and persisted throughout the experiment. Recombinant human IL-1 alpha induced the following: (1) an early, transient decline in granulocytes followed by a sustained granulocytosis; (2) a lymphopenia; and (3) a transient monocytopenia followed by a gradual return to baseline. Although IL-1ra had no effect on leukocyte kinetics with either live E. coli or LPS, the IL-1ra significantly abrogated the monocytopenia seen with recombinant human IL-1 alpha administration alone.

CONCLUSIONS

These results suggest that administration of recombinant human IL-1 alpha can replicate some of the characteristic patterns of hematologic change associated with bacteremia and endotoxemia. However, an endogenous IL-1 response is not required for these changes to occur. Rather, the data suggest that other inflammatory mediators induced by endotoxemia or gram-negative bacteremia, such as tumor necrosis factor-alpha (TNF alpha), may be involved.