SARS-CoV-2 infection is not associated with the emergence of monoclonal gammopathies

BACKGROUND

Upon infection activated plasma cells produce large quantities of antibodies which can lead to the emergence of a monoclonal component (MC), detectable by serum protein electrophoresis (SPEP). This study aims to investigate any correlation between SARS-CoV-2 infection and MC development and, if identified, whether it persists during follow-up.

METHODS

SPEPs of 786 patients admitted to hospitals between March 01 2020 and March 31 2022 were evaluated. Positive (SARS-CoV-2+) and negative (SARS-CoV-2-) patients to nasopharyngeal swab for SARS-CoV-2 by RT-PCR were included. The persistence/new occurrence of MC was investigated for all patients during follow-up. Patient groups were compared by chi-square analysis.

RESULTS

MC was identified in 12% of all patients admitted to hospital, of which 28.7% were SARS-CoV-2+. The most common immunoglobulin isotype in both groups was IgG-k. There was no correlation between MC development and SARS-CoV-2 infection (p = 0.173). Furthermore, the risk of MC persistence in SARS-CoV-2-negative patients was revealed to be higher than in the SARS-CoV-2+ at follow-up (HR = 0.591, p = 0.05).

CONCLUSIONS

Our study suggests that the detection of MC during SARS-CoV-2 infection is most likely due to the hyperstimulation of the humoral immune system, as also occurs in other viral infections.

Calprotectin: two sides of the same coin

Calprotectin (CLP) is a calcium-binding protein produced by neutrophils and monocytes in the course of inflammation. Today, the role of faecal CLP in chronic IBD is well known, but in recent years attention has shifted towards circulating CLP. In fact, this molecule can be measured in different biological fluids: blood, saliva and urine, using different analytic methods that are described in this review. Furthermore, different data confirm the relevant role of serum CLP in autoimmune diseases. In this review we will highlight the correlation between high levels of circulating CLP and specific autoantibodies of major autoimmune pathologies paving the way to the employment of CLP measurement as useful biomarker for monitoring outcome in different pathologies.

NLRP3 Inflammasome Involvement in Heart, Liver, and Lung Diseases-A Lesson from Cytokine Storm Syndrome

Inflammation and inflammasomes have been proposed as important regulators of the host-microorganism interaction, playing a key role in morbidity and mortality due to the coronavirus disease 2019 (COVID-19) in subjects with chronic conditions and compromised immune system. The inflammasome consists of a multiprotein complex that finely regulates the activation of caspase-1 and the production and secretion of potent pro-inflammatory cytokines such as IL-1β and IL-18. The pyrin containing NOD (nucleotide-binding oligomerization domain) like receptor (NLRP) is a family of intracellular receptors, sensing patterns associated to pathogens or danger signals and NLRP3 inflammasome is the most deeply analyzed for its involvement in the innate and adaptive immune system as well as its contribution to several autoinflammatory and autoimmune diseases. It is highly expressed in leukocytes and up-regulated in sentinel cells upon inflammatory stimuli. NLRP3 expression has also been reported in B and T lymphocytes, in epithelial cells of oral and genital mucosa, in specific parenchymal cells as cardiomyocytes, and keratinocytes, and chondrocytes. It is well known that a dysregulated activation of the inflammasome is involved in the pathogenesis of different disorders that share the common red line of inflammation in their pathogenetic fingerprint. Here, we review the potential roles of the NLRP3 inflammasome in cardiovascular events, liver damage, pulmonary diseases, and in that wide range of systemic inflammatory syndromes named as a cytokine storm.

A new challenge for urinary free light chains: assessment of the upper reference limit in healthy subjects

OBJECTIVE

Free light chains (FLCs) can be measured in both urine (uFLC) and serum (sFLC) in immunochemistry. We aim to compare FLC levels in serum and urine assessed among healthy volunteers and measured upper reference limits (URLs) of urinary FLC to creatinine ratio (uFLC/uCr) in mg/g to compare with the manufacturer's recommended URLs.

PATIENTS AND METHODS

Eligibility criteria: normal serum and urine FLC measure and negative serum/urinary immunofixation. Immunoturbidimetry was used to assess both κ and λ FLCs. The URLs were calculated with the 97.5th percentile of uFLC concentrations according to the Clinical and Laboratory Standards Institute recommendations.

RESULTS

126 healthy subjects (median age 46 years, 62% females) met the inclusion criteria. Median concentrations of κ and λ sFLCs were similar both for males and females without significant differences. κ and λ uFLCs were significantly higher in males than in females (p < 0.001 and p = 0.004, respectively). Slower clearance for λ FLC compared to κ FLC was observed with an increased κ/λ uFLC ratio in both males and females. URLs for male and female subjects: κ uFLC mg/g uCr = 34.35 vs. 23.18, and λ uFLC mg/g uCr = 3.59 vs. 1.96, respectively compared well with manufacturer's URLs.

CONCLUSIONS

FLC catabolism is gender-dependent and occurs less rapidly in λ FLC than in κ FLC. The determination of the URL of uFLC, as uFLC/uCr, in healthy subjects in morning urine, proved to be consistent with the manufacturer's recommendations, but with a significant difference according to gender.

Prognostic Relevance of Multi-Antigenic Myeloma-Specific T-Cell Assay in Patients with Monoclonal Gammopathies

Multiple Myeloma (MM) typically originates from underlying precursor conditions, known as Monoclonal Gammopathy of Undetermined Significance (MGUS) and Smoldering Multiple Myeloma (SMM). Validated risk factors, related to the main features of the clonal plasma cells, are employed in the current prognostic models to assess long-term probabilities of progression to MM. In addition, new prognostic immunologic parameters, measuring protective MM-specific T-cell responses, could help to identify patients with shorter time-to-progression. In this report, we described a novel Multi-antigenic Myeloma-specific (MaMs) T-cell assay, based on ELISpot technology, providing simultaneous evaluation of T-cell responses towards ten different MM-associated antigens. When performed during long-term follow-up (mean 28 months) of 33 patients with either MGUS or SMM, such deca-antigenic myeloma-specific immunoassay allowed to significantly distinguish between stable vs. progressive disease (p < 0.001), independently from the Mayo Clinic risk category. Here, we report the first clinical experience showing that a wide (multi-antigen), standardized (irrespective to patients' HLA), MM-specific T-cell assay may routinely be applied, as a promising prognostic tool, during the follow-up of MGUS/SMM patients. Larger studies are needed to improve the antigenic panel and further explore the prognostic value of MaMs test in the risk assessment of patients with monoclonal gammopathies.

Analysis of cryoproteins with a focus on cryofibrinogen: a study on 103 patients

OBJECTIVES

Cryofibrinogen (CF) is an abnormal protein in plasma that precipitates at 4 °C and dissolves at 37 °C. Whilst serum cryoglobulins (CGs) analysis is common practice, CF investigation is rarely performed. This study aims to describe the testing methodology developed at our laboratory, potential pitfalls for all analytical phases, the distribution among hospital wards and clinical conditions underlying test requests and clinical conditions in which to order CF analysis is useful.

METHODS

Retrospective analysis of laboratory samples received between January 2019 and June 2021 with CF testing requests.

RESULTS

A complete protocol for CF pre-analytical, analytical and post-analytical phases are supplied. Most test requests were received from the rheumatology department for systemic sclerosis or liver transplant screening. Among the 103 in-patients included, CF+ was confirmed in 68 patients (66%). Of observed CF+ patients (n=68) most cases were CGs- (n=44, 67%). Isolated CF was found in 43% of the cases. Among CF- patients (n=35; 34%) only 2 patients had positive CGs (CGs+). Among rheumatology patients (n=66), isolated CF+ was observed in 45% (n=30/66), whilst among patients with systemic sclerosis with CF+ (n=19), isolated CF+ was detected in 79% (n=15/19).

CONCLUSIONS

Described analytical procedures may be used for the creation of harmonized recommendations and indications for CF analysis. Isolated CF positivity among hospitalized patients, predominantly rheumatology and systemic sclerosis patients, appears higher than rates previously reported in literature. We propose CF test recommendations should be included in investigation protocols for diseases where cryofibrinogenemia may occur.

The dark side of current analytic methods for Bence Jones Proteinuria

OBJECTIVE

Bence Jones proteinuria (BJP) refers to monoclonal free immunoglobulin light chains detected in urine, deriving from the clonal expansion of plasma cells in the bone marrow in patients with plasma cell dyscrasias, associated with monoclonal gammopathies of uncertain origin. This review summarizes routinely diagnostic procedures to assess BJP highlighting critical steps of pre-analytical, analytical, and post-analytical phases.

QUALITATIVE AND QUANTITATIVE METHODS

The best option for BJP detection is the first morning void urine sample and immunofixation electrophoresis detection technique (IFE) the recommended method, with the employment of specific polyvalent antisera. Other qualitative tests for a quick evaluation of BJP are currently available. Densitometric analysis performed on the 24-hour urine is the recommended method to quantify BJP. To overcome the 24-hour collection, it is possible to use morning urine sample and correlate the assessed value of BJP to creatininuria. In addition to the traditional ones, we here reviewed screening methods currently used to avoid false negatives and reduce the time around test (TAT), together with immunochemical quantification methods for increased sensitivity, after checking BJP by IFE. Mass spectrometry emerges as a new challenge in the determination of BJP.

CONCLUSIONS

The employment of different based-assays methods may be useful for diagnostic purposes to improve the accuracy of BJP monitoring in monoclonal gammopathies.

POS0896 CRYOFIBRINOGEN-ASSOCIATED SYSTEMIC SCLEROSIS: POSSIBLE CORRELATIONS WITH SCLERODERMA DIGITAL ULCERS AND PULMONARY ARTERIAL HYPERTENSION

Background

Cryofibrinogenemia (CF) is a rare disorder characterized by the presence of an abnormal protein in the plasma that precipitates when cooled and redissolves at room temperature (1). CF is rarely symptomatic, therefore it is often underestimated. Nevertheless, the cryoprecipitation of native fibrinogen could induce thrombotic occlusion of small and medium sized vessels; as a consequence, this condition could become potentially lethal without the proper treatments. CF is classified into an essential and secondary form. The association of CF with Systemic Sclerosis (SSc) is described in literature (2-4); however, the role of this phenomenon it is not completely clarified, especially because some clinical aspects could be similar in both conditions.

Objectives

The aim of our study was to analyze the clinical, laboratory, instrumental and therapeutic features of SSc patients with cryofibrinogenemia, with particular attention to the possible prevention strategy and appropriate therapy of SSc digital ulcers.

Methods

101 SSc patients (M:F 1:13) referring to the SSc Unit-Rheumatology Unit of our University Hospital have been tested both for cryofibrinogen and cryoglobulins from February 2020 to January 2022. Clinical, laboratory, instrumental features and ongoing therapies were collected.

Results

Patients with diffuse cutaneous form, limited cutaneous form, and sine-scleroderma subsets were 20 (19,8%), 79 (78,2%), and 2 (2,0%), respectively. The overall positivity for CF was 69,3%, of which 90,7% as isolated CF and 9,3% in addition to cryoglobulins. No correlation between CF positivity and positivity for rheumatoid factor, Scl-70, CENP B, anti-fibrillarin, anti-U1RNP, anti-Th/To, anti-Ku, anti-MDA5, anti-mitochondrial, anti-SSA, anti-SSB, anti-citrullinated peptide, anti-phospholipids, anti-CORE, and anti-HCV antibodies was observed. An inverse correlation trend between CF positivity and anti-RNAP3 antibodies positivity (OR=0.0577, 95% CI 0.0029-1.1537, p=0.0620) was noted. No significant correlation between CF positivity and interstitial lung disease, pulmonary arterial hypertension (PAH), history of digital ulcers, and amputation was recorded; however, considering cryocrit sample ≥1%, a correlation between the presence of an estimated pulmonary arterial systolic pressure (ePASP) higher than 30 mmHg and the positivity of CF was obtained (OR = 2.71, 95% CI 1.01-7.28, p=0.0482). The same association was achieved if we considered patients without endothelin receptor antagonist therapy (n=47) and CF positivity (OR=6.19, 95% CI 1.19-32.2, p=0.0304). Furthermore, no correlation between CF positivity and the presence of digital ulcers at the moment of the blood sampling was verified; however, if we stratified patients according to their ongoing treatments (absence of an endothelin receptor antagonists therapy plus PDE5 inhibitors), a significant correlation between digital ulcers and CF positivity emerged (OR=8.14, 95% CI 1.03-64,5, p=0.0470, n=91).

Conclusion

Our preliminary results on this issue are extremely interesting as they can open new perspectives on the identification of cryofibrinogen as possible prognostic marker that could be involved in the pathogenesis of scleroderma digital ulcers and PAH. Moreover, therapies which are currently used for the treatment of PAH and the management of digital ulcers, could determine circulating cryofibrinogen disappearance, with possible challenging future impact on SSc therapeutic approaches.

References

[1]Michaud M, Pourrat J. Cryofibrinogenemia. J Clin Rheumatol Pract Rep Rheum Musculoskelet Dis. aprile 2013;19(3):142–8.

[2]Kao L, Weyand C. Vasculitis in Systemic Sclerosis. Int J Rheumatol. 30 settembre 2010;2010:e385938.

[3]Kocoloski A et al, Successful management of secondary cryofibrinogenaemia using bosentan therapy. Rheumatol Oxf Engl. 1 ottobre 2018;57(10):1868–70.

[4]Barrett MC et al, Cryofibrinogenaemia and acute gangrene in systemic sclerosis. Postgrad Med J. ottobre 1986;62(732):935–6.

Disclosure of Interests

None declared

Inter-Laboratory Concordance of Cerebrospinal Fluid and Serum Kappa Free Light Chain Measurements

The kappa index (K-Index), calculated by dividing the cerebrospinal fluid (CSF)/serum kappa free light chain (KFLC) ratio by the CSF/serum albumin ratio, is gaining increasing interest as a marker of intrathecal immunoglobulin synthesis. However, data on inter-laboratory agreement of these measures is lacking. The aim was to assess the concordance of CSF and serum KFLC measurements, and of K-index values, across different laboratories. KFLC and albumin of 15 paired CSF and serum samples were analyzed by eight participating laboratories. Four centers used Binding Site instruments and assays (B), three used Siemens instruments and assays (S), and one center used a Siemens instrument with a Binding Site assay (mixed). Absolute individual agreement was calculated using a two-way mixed effects intraclass correlation coefficient (ICC). Cohen’s kappa coefficient (k) was used to measure agreement on positive (≥5.8) K-index values. There was an excellent agreement in CSF KFLC measurements across all laboratories (ICC (95% confidence interval): 0.93 (0.87–0.97)) and of serum KFLC across B and S laboratories (ICC: 0.91 (0.73–0.97)), while ICC decreased (to 0.81 (0.53–0.93)) when including the mixed laboratory in the analysis. Concordance for a positive K-Index was substantial across all laboratories (k = 0.77) and within S laboratories (k = 0.71), and very good (k = 0.89) within B laboratories, meaning that patients rarely get discordant results on K-index positivity notwithstanding the testing in different laboratories and the use of different platforms/assays.

Kappa Index Versus CSF Oligoclonal Bands in Predicting Multiple Sclerosis and Infectious/Inflammatory CNS Disorders

Background: Cerebrospinal fluid (CSF) kappa free light chains (KFLC) are gaining increasing interest as markers of intrathecal immunoglobulin synthesis. The main aim of this study was to assess the diagnostic accuracy (AUC) of the kappa index (CSF/serum KFLC divided by the CSF/serum albumin ratio) compared to CSF oligoclonal IgG bands (OCB) in predicting Multiple Sclerosis (MS) or a central nervous system infectious/inflammatory disorder (CNSID). Methods: We enrolled patients who underwent a diagnostic spinal tap throughout two years. KFLC levels were determined using a Freelite assay (Binding Site) and the turbidimetric Optilite analyzer. Results: Of 540 included patients, 223 had a CNSID, and 84 had MS. The kappa index was more sensitive (0.89 versus 0.85) and less specific (0.84 versus 0.89), with the same AUC (0.87) as OCB for MS diagnosis (optimal cut-off: 6.2). Adding patients with a single CSF IgG band to the OCB-positive group slightly increased the AUC (0.88). Likewise, the kappa index (cut-off: 3.9) was more sensitive (0.67 versus 0.50) and less specific (0.81 versus 0.97), with the same AUC (0.74) as OCB, for a CNSID diagnosis. Conclusion: The kappa index and CSF OCB have comparable diagnostic accuracies for a MS or CNSID diagnosis and supply the clinician with useful, complementary information.

AB0525 NATURAL HISTORY OF CRYOGLOBULINEMIA FROM 2000 TO 2018 FROM THE LABORATORY POINT OF VIEW: AN ANALYSIS OF CRYOGLOBULIN CHARACTERISTICS IN A SINGLE CENTER

Background:

Big data refers to large amounts of information. With today’s ever-improving technologies created by the automation and digitization, it becomes easier to convert data into relevant information, which can be used to provide better patient management, especially when it occurs a rare condition such as cryoglobulinemia (CRG).

CRG is due to an immunoglobulins (Ig) that precipitate at low temperatures. There are 3 types of CRG: type I: monoclonal Ig; type II: monoclonal Ig + polyclonal Ig; type III: 2 polyclonal Ig.

Objectives:

The aim of this study was to analyse the available data coming to the Department of Laboratory Medicine of Modena to describe the population of patients suffering of CRG.

Methods:

Data from the Modena Labs network were extracted by means of the software “Pagoda”, for statistical purposes, directly connected to the Laboratories Information System (LIS). Considered time period 2000-2018

Results:

The analysed samples were 28,847, 4901 (17%) of which positive to the cryoglobulins (CR) detection. The typing positive CR were 4190 (85%): type 1 7.8 %, type II 48.54% and type III 43.8% The positive samples belonged to 2528 patients. Patients were 1563 (62%) women, average age 66±16, and 965 (38%) men, average age 62±16. (female/male ratio = 1.62) No statistically significant difference regarding sex and age between the 3 types. The cryoglobulinemia phenomenon is quite complex and the typing of monoclonal, polyclonal components of the Ig classes and chains has made it possible to identify 41 possible combinationsOut of 115 patients with Type 1 cryoglobulin, 73% had a monoclonal IgM and 36% monoclonal IgG; 11.2% both monoclonal IgG and IgM. The к light chain was the most frequent: 55,6% IgM-k and 23,4% IgG-k vs 29% IgM-λ and 18.2% IgG-λ. Two patients had an IgA-k cryoglobulin.

Patients with Type 2 cryo were 781: monoclonal IgM-k 587 (75.1 %), 126 IgM-λ (16.1 %), 52 IgG-k (6.6 %), IgG-λ (5%), 1 IgA-λ; 2.8% had both IgG and IgM. Out of 1204 patients with Type 3 cryo, 74.8% had both polyclonal IgG and IgM, 13,8% had isolated IgM or IgG (9%); 4.8 % IgG-IgA-IgM together, both IgG and IgA in only 0,5% of patients. Almost the 50% (1255) of the patients had a diagnosis supporting the request of CR:

HCV, 604 (48%); chronic hepatitis, 177 (14%); rheumatologic disorder, 107 (9%); autoimmune diseases, 83 (7%), nephropathy, 80 (7%); others, 204 (15%).

Genotyped HCV+ patients were 290 (48%), with the following results: 1b, 136 (47%); 2a/2c, 65 (22%); 3a, 26 (9%); others 63 (22%).

Conclusion:

The data show that CRG is a pathology which affects the elderly and especially women, as in autoimmune and rheumatological diseases. The predominant CRG type is the III and the most frequently related pathology to the request for CR is HCV+ and chronic hepatitis. The most common HCV genotype are 1b and 2a/2c The cryoglobulinemia phenomenon is complex and laboratory typing is intriguing.

Starting from this preliminary descriptive study, it will be possible, with the available data, to perform elaborations that allow to relate CRG with the diagnosis and verify the effect of therapy.

Big Data methods’ application represents an undeniable resource for public institutions when carrying out strategic decision-making processes.

Disclosure of Interests:

None declared

Alternaria spores at different heights from the ground

BACKGROUND

Alternaria tenuis (Alt) is one of the main allergens in pediatric age. In temperate climates, airborne Alt spores are detectable from May to November with peaks in late summer and autumn. Sensitized children display symptoms even in the absence of airborne Alt spores. Alt spore concentration, as well as pollen, is usually detected by fixed devices located on the roof of a building at a height of 10-20 m. The aim of the current study is to find out whether ground-level (50 cm) Alt spore concentrations are different from those at roof-top level, even during low-concentration periods.

METHODS

Alt samples were taken simultaneously using a Hirst fixed volumetric collector (FVC) placed on a 15 m-high roof and by a portable volumetric collector (PVC). Firstly, the results of FVC and PVC, both placed on the roof-top, were compared to verify the correlation coefficient of the two samplers. Subsequently, the PVC was placed 50 cm above the ground in a courtyard (30 samplings) and in private green areas (50 samplings). The results were compared by statistical analysis (Student's t-test or K-S test).

RESULTS

The values of the 20 samples taken jointly in summer time (FVC 195 +/- 134 spores/m(3); PVC = 134 +/- 131 spores/m(3)) showed a good correlation between the two samplers (r = 0.850; P < 0.01), with a correction factor equal to 1.177. 1. Thirty samples obtained in summer and winter when the PVC was positioned in an enclosed courtyard directly below the FVC showed no significant difference (PVC, 181 +/- 194 spores/m(3); FVC, 152 +/- 145 spores/m(3); P = 0.221). 2. Fifty samples taken by PVC placed in private green areas in a low-concentration period, showed significantly higher concentrations than by FVC: PVC, 531 +/- 925 spores/m(3); FVC, 25 +/- 51 spores/m(3) (K-S test: P < 0.0001). In particular, 33 samples taken in winter when Alt counts by FVC were <10 spores/m(3) still demonstrated highly significant differences: PVC, 398 +/- 961 spores/m(3); FVC, 2.0 +/- 2 spores/m(3) (K-S test: P < 0.0001).

CONCLUSION

Our results lead to the conclusion that Alt spore concentration is significantly higher at ground level in the presence of vegetation, even when the spore concentration is very low (<10 spores/m(3)). These results further suggest that the individual's exposure to Alt, especially in the case of children, is underestimated by samples taken at roof-top level by FVC.

Descending necrotizing mediastinitis. Diagnosis and surgical treatment

AIM

Descending necrotizing mediastinitis (DNM) is an unusual and severe disease with a high mortality rate. Surgical management remains controversial. Our investigations reviews the most effective surgical treatment in the management of this rare pathology.

METHODS

Seven patients with DNM and treated over a 20-year period are reported. All patients were evaluated according to the classification suggested by Endo et al. of the degree of mediastinal diffusion, based on CT scan findings. Five patients underwent combined cervical drainage and thoracotomy, 2 patients were treated with cervical drainage alone.

RESULTS

The outcome was favorable in 5 patients, 4 treated with a combined cervical and thoracic approach and 1 with a cervical approach alone. Two patients that underwent a combinated cervical and thoracic approach alone, died of septic shock. Overall mortality rate was 28.5%.

CONCLUSION

Early diagnosis and early, aggressive surgical treatment are required to improve the poor prognosis of DNM. Although a unique surgical management is still not completely accepted, we state, in agreement with other authors, a wide approach consisting of a cervical drainage and mediastinotomy in case of upper mediastinitis and a combined cervical and thoracic approach in case of lower mediastinitis. In the course of thoracotomy a wide excision of necrotic and particularly fat mediastinal tissue is needed, to avoid a recurrent infection. A continuous cervico-mediastinal irrigation system is suggested during the postoperative period.

Thyroid abscess associated with a substernal goiter. Case report

An abscess associated with an intrathoracic goiter is an extremely rare condition. The authors report a case of a thyroid abscess complicated by acute dyspnea and asphyxia in a patient of geriatric age with a substernal goiter. Surgical therapy was necessary to obtain a correct diagnosis and an effective treatment.

Differential effect of human and murine polyclonal and monoclonal antisera on TNF-alpha production by human monocytes

The capacity of human and murine polyclonal and monoclonal antibodies to inhibit lipopolysaccharide (LPS)-induced tumor necrosis factor-alpha (TNF-alpha) release from human monocytes was investigated. Human pooled immunoglobulin G (IVIG), human IgM monoclonal antibody (HA-1A) directed against the lipid A moiety of LPS, and murine IgG monoclonal antibody (MT-1F) raised in mice against antibiotic-treated Escherichia coli O6:K- were either added simultaneously with LPS to monocytes or preincubated for 1 h at 37 degrees C before being added to monocytes. TNF-alpha content in the monocyte supernatants was then tested. Simultaneous addition of increasing concentrations of IVIG (from 0.3 to 2.5 mg/ml) and 10 micrograms/ml of LPS to monocytes induced an enhanced release of TNF-alpha by monocytes in a dose dependent fashion. Preincubation of IVIG with LPS abolished the additive effect, but did not inhibit LPS-induced TNF-alpha release by monocytes. The simultaneous addition of LPS and HA-1A to monocytes had no additive effect nor did it inhibit TNF-alpha release. On the other hand, inhibition of TNF-alpha release was observed when HA-1A was preincubated with LPS before being added to monocytes. In all instances MT-1F inhibited TNF-alpha release when the monocytes were stimulated with smooth type LPS, but not with LPS isolated from rough mutants.

Expression of HER-2/neu oncoprotein, DNA-ploidy and S-phase fraction in advanced ovarian cancer

The immunohistochemical expression of HER-2/neu and cytofluorimetric data were retrospectively analyzed in a group of primary advanced ovarian cancers. Thirty-three out of 94 (35%) cases showed a specific p185/neu immunoreaction. No correlation between p185/neu expression and any of the clinico-pathologic parameters examined was observed. As far as cytofluorimetric data are concerned, 38 out of 69 (55%) of the tumors were diploid (DNA index = 1) while 31 (45%) were aneuploid (DNA index from 1.10 to 2.50 with a median value of 1.50). Ovarian tumors were defined as of low and high S-phase fraction in 68% and 32% of the cases, respectively. Tumor ploidy and S-phase fraction did not correlate with the clinico-pathologic characteristics or p185/neu oncoprotein expression. Aneuploid tumors had a higher S-phase fraction (mean: 15.81 +/- 13.44) than diploid tumors (mean: 8.89 +/- 7.98) (P < 0.01). p185/neu expression failed to affect significantly both overall and progression free survival. On the other hand tumor ploidy was found to be related to the prognosis of advanced ovarian cancer patients although the difference was not statistically significant. As far as progression free survival is concerned, the median time to recurrence was not reached for diploid cases whereas it was 21 months for aneuploid cases (P < 0.05). The 5-year survival for patients with a low S-phase fraction (58%) was significantly higher than for patients with high S-phase fraction tumors (28%) (P < 0.01). Median time to recurrence was 48 and 17 months for low and high S-phase fraction tumor patients, respectively (P < 0.05). However, in a multivariate analysis both tumor ploidy and S-phase fraction did not retain their prognostic value. The assessment of the role of the parameters examined in improving the prognostic characterization of ovarian cancer patients should be investigated in large multicenter clinical trials.

Differential expression of intercellular adhesion molecule 1 in primary and metastatic melanoma lesions

Immunochemical studies have shown that the monoclonal antibody (MoAb) CL203.4, elicited with immune interferon treated cultured human melanoma cells Colo 38, recognizes intercellular adhesion molecule 1 (ICAM-1). The determinant defined by MoAb CL203.4 is distinct and spatially distant from that defined by anti-ICAM-1 MoAb RR1/1, which had been elicited with Epstein-Barr virus-transformed B-lymphocytes from a lymphocyte function associated antigen 1 deficient patient. Immunohistochemical testing with MoAb CL203.4 of surgically removed lesions of melanocyte origin has shown a markedly lower reactivity with benign than with malignant lesions. Among the latter, a higher percentage of metastatic than of primary lesions was stained by MoAb CL203.4. The higher expression of ICAM-1 in metastases than in primary lesions is unique to melanoma, since no difference was found in its distribution in primary and metastatic lesions of a variety of malignancies of different embryological origin. Reactivity with MoAb CL203.4 of primary lesions removed from patients with stage I melanoma showed a highly significant correlation with the lesion thickness and with the clinical course of the disease. The disease free interval in patients without detectable reactivity of their primary lesion with MoAb CL203.4 was significantly (P = 0.004) longer than that of patients whose primary lesion was stained with MoAb CL203.4. These results suggest that ICAM-1 may be a useful marker in the analysis of the molecular mechanism underlying the association between lesion thickness and clinical course of the disease.

Accessory cell function of human melanoma cells in mitogen-induced T cell proliferation

Six out of eight human melanoma cell lines were found to be able to function as accessory cells in PHA-induced proliferation of autologous and allogeneic T cells. The accessory cell function of the melanoma cell lines appears to be similar to that of monocytes, requires the presence of viable cells, and does not correlate with the cell surface binding sites for PHA and with the level of expression of HMW-MAA and of HLA Class I antigens. HLA Class II antigens do not appear to play a major role in these phenomena, since there is no relationship between level of expression of HLA Class II antigens and accessory cell function of melanoma cells. Furthermore, addition of anti-HLA Class II monoclonal antibodies does not affect proliferation of T cells stimulated with PHA in the presence of melanoma cells with accessory cell function. Although melanoma cells exert accessory cell function, functional and immunological assays did not detect IL-1 in the spent medium of the melanoma cell lines. Furthermore, Northern blotting analysis with IL-1 alpha and IL-1 beta probes did not detect IL-1-specific mRNA in melanoma cell lines. These results suggest that PHA-induced proliferation of T cells in the presence of melanoma cells can bypass the requirement for IL-1 or utilizes factors other than IL-1.

Expression of class I and class II major histocompatibility complex antigens on human hepatocytes

We analyzed whether normal human hepatocytes, which normally do not display Class II major histocompatibility complex antigens, can be induced to express them in vitro, and whether this induction has an in vivo counterpart in chronic liver diseases. While both alpha- and gamma-interferon induced expression of Class I antigens, only gamma-interferon induced expression of Class II antigens on hepatocytes in vitro. Recombinant interleukin 2 had no effect on major histocompatibility complex antigen expression. Both Class I and Class II antigens could be detected by indirect immunofluorescence on hepatocytes from patients with various forms of chronic liver disease, regardless of etiology. These findings suggest that gamma-interferon produced by T lymphocytes that infiltrate the liver during the course of chronic hepatitis induces Class II major histocompatibility complex antigen expression and may endow the hepatocytes with the capacity to perform accessory (antigen-presenting) cell functions.

Gene products of the HLA-D region in normal and malignant tissues of nonlymphoid origin

Indirect immunofluorescence staining with monoclonal antibodies has shown a differential distribution of HLA-DR, DQ, and DP antigens in normal tissues of nonlymphoid origin. The distribution of HLA-DP antigens is similar to that of HLA-DR antigens, while that of HLA-DQ antigens is more restricted. Malignant transformation of cells of nonlymphoid origin may be associated with the appearance of the gene products of the HLA-D region. HLA-DR antigens appear more frequently than the other two types of HLA class II antigens and HLA-DP antigens more frequently than HLA-DQ antigens. Differential expression of the gene products of the HLA-D region was also found in autologous metastases removed from different anatomic sites from patients with melanoma. The HLA class II phenotype of surgically removed malignant lesions did not correlate with the degree of differentiation of tumor cells and/or with the expression and/or cellular distribution of HLA class I antigens. Furthermore, in melanoma lesions, no relationship was found between the HLA class II phenotype and the expression of 3 membrane bound and 1 cytoplasmic melanoma associated antigen recognized by monoclonal antibodies. The functional significance and the practical implications of the differential expression of the gene products of the HLA-D region by tumor cells are discussed.

Distribution of a cross-species melanoma-associated antigen in normal and neoplastic human tissues

In previous studies the monoclonal antibody (MoAb) M2590 elicited in C57/BL6 mice with the syngeneic melanoma cell line B16 has been shown to recognize a 31K glycoprotein expressed by human melanoma cell lines. The present study has shown that the MoAb M2590 cross-reacts with surgically removed benign and malignant lesions of melanocyte origin. The reactivity pattern of the MoAb M2590 with these lesions is different from that of the anti-high-molecular weight-melanoma associated antigen (HMW-MAA) MoAb 225.28S, of the anti-115K MAA MoAb 345.134S, and of the anti-100K MAA MoAb 376.96S, which were elicited with human melanoma cell lines. In particular, the MoAb M2590 reacts with blue nevi. The MoAb M2590-defined MAA, like other types of MAA, is heterogeneous in lesions removed from different patients, in autologous lesions removed from different anatomic sites, and in cells within a lesion. The distribution of the MoAb M2590-defined MAA in normal tissues and in tumors of nonmelanocyte origin is broader than that of the HMW-MAA, but is similar to that of the 115K MAA and of the 100K MAA. The results of this investigation suggest that immunization with xenogeneic melanoma cells may broaden the range of specificity of antihuman MAA MoAbs and provide information about the phylogenetic evolution of MAAs.

Analysis of the interaction between a human high molecular weight melanoma-associated antigen and the monoclonal antibodies to three distinct antigenic determinants

The restricted tissue distribution and the limited heterogeneity that appear in melanoma lesions of the high M.W. melanoma-associated antigen (HMW-MAA) suggest that this antigen may be an appropriate marker for radioimaging, and a useful target for immunotherapy in patients with melanoma. Therefore, in this study we analyzed other characteristics that are important in the selection of reagents for radioimaging and immunotherapy purposes. The affinities of the monoclonal antibodies (MoAB) 149.53, 225.28S, and 763.74T to distinct determinants of the HMW-MAA were found to be at least 1 X 10(8) mol/L. Furthermore, the effects of the concentrations of unlabeled MoAb on the dissociation rates suggest that the binding of MoAb 149.53 and 225.28S to melanoma cells (Colo 38) is preferentially bivalent, whereas that of MoAb 763.74T is preferentially univalent. These results suggest that the latter MoAb is the reagent of choice for assays that make use of soluble HMW-MAA, whereas the former two are the reagents of choice for assays with membrane-bound HMW-MAA, such as imaging with radiolabeled MoAb. The density of the HMW-MAA on cultured Colo 38 melanoma cells appears to be in the range of approximately 5 X 10(6) molecules/cell. The HMW-MAA was not susceptible to MoAb-mediated modulation under a variety of experimental conditions that included various concentrations of modulating MoAb, different incubation times, the use of an anti-mouse Ig antiserum, and the relaxation of equilibrium by diluting cells in MoAb-free medium. These results indicate that the HMW-MAA and the available corresponding MoAb meet the criteria to be reagents for radioimaging and immunotherapy in patients with melanoma.

Analysis of the interaction between a human high molecular weight melanoma-associated antigen and the monoclonal antibodies to three distinct antigenic determinants

The restricted tissue distribution and the limited heterogeneity that appear in melanoma lesions of the high M.W. melanoma-associated antigen (HMW-MAA) suggest that this antigen may be an appropriate marker for radioimaging, and a useful target for immunotherapy in patients with melanoma. Therefore, in this study we analyzed other characteristics that are important in the selection of reagents for radioimaging and immunotherapy purposes. The affinities of the monoclonal antibodies (MoAB) 149.53, 225.28S, and 763.74T to distinct determinants of the HMW-MAA were found to be at least 1 X 10(8) mol/L. Furthermore, the effects of the concentrations of unlabeled MoAb on the dissociation rates suggest that the binding of MoAb 149.53 and 225.28S to melanoma cells (Colo 38) is preferentially bivalent, whereas that of MoAb 763.74T is preferentially univalent. These results suggest that the latter MoAb is the reagent of choice for assays that make use of soluble HMW-MAA, whereas the former two are the reagents of choice for assays with membrane-bound HMW-MAA, such as imaging with radiolabeled MoAb. The density of the HMW-MAA on cultured Colo 38 melanoma cells appears to be in the range of approximately 5 X 10(6) molecules/cell. The HMW-MAA was not susceptible to MoAb-mediated modulation under a variety of experimental conditions that included various concentrations of modulating MoAb, different incubation times, the use of an anti-mouse Ig antiserum, and the relaxation of equilibrium by diluting cells in MoAb-free medium. These results indicate that the HMW-MAA and the available corresponding MoAb meet the criteria to be reagents for radioimaging and immunotherapy in patients with melanoma.

Heterogeneous expression of melanoma-associated antigens and HLA antigens by primary and multiple metastatic lesions removed from patients with melanoma

Indirect immunofluorescence staining with a large battery of monoclonal antibodies of primary and autologous metastatic lesions removed from seven patients with melanoma has detected heterogeneity in the expression of various types of melanoma-associated antigens (MAAs), of distinct determinants of the high molecular weight melanoma-associated antigen (HMW-MAA), of the two subunits of Class I HLA antigens, and of the gene products of the HLA-D region. Among the 10 MAAs tested, the HMW-MAA had the highest frequency and the Mr 87,000 MAA the lowest. Furthermore, the HMW-MAA displayed the lowest heterogeneity. These findings, in conjunction with the restricted tissue distribution of the HMW-MAA, its lack of susceptibility to antibody-mediated modulation, and the high affinity of the available anti-HMW-MAA monoclonal antibodies, indicate that this antigen may be a useful marker for radioimaging and immunotherapy in patients with melanoma. The common acute lymphoblastic leukemia antigen was detected only in five lesions. Class I HLA antigens were detected in a larger number of lesions than HLA-DR antigens, which had a significantly higher frequency than HLA-DQ antigens. The degree of antigenic heterogeneity did not appear to correlate with the histopathological features of the lesions and/or with the clinical course of the disease. The results of the present study indicate that immunodiagnostic and immunotherapeutic approaches to melanoma should rely on the use of combinations of monoclonal antibodies to distinct MAAs.

[Hypokalemic myopathy in arterial hypertension]

Three cases of arterial hypertension and severe hypokaliemia are reported; in two cases an acute rhabdomyolisis was also observed. The syndrome was iatrogenic in two cases depending on the licorice eating and the combined use of diuretics and a 9-alpha-fluoroprednisolone-containing nasal spray in one patient, and on a long-term use of the same nasal decongestant in the other. In the patient 2 the persistence of low PRA and aldosterone levels seems to indicate an excess of mineralcorticoid activity other than aldosterone. The syndrome of factitious mineralcorticoid excess should, therefore, be considered in the differential diagnosis of arterial hypertension with hypokaliemia; the risks of a long-term administration of steroid-containing nasal sprays, responsible of serious side effects, should also be stressed.

Unchanged antigenic properties of a nuclear non-histone protein during phylogenesis

The phyletic distribution of Sm antigen in eukaryotes has been investigated by means of immuno-chemical techniques. This nuclear antigen, which is an acidic glycoprotein of about 7S with DNA binding ability, is present in all organisms examined. Such evidence suggests a very slow evolutionary rate for at least the antigenic determinant(s) of the Sm antigen.

Malignant lentigo-melanoma--a comparative histological and electron microscopy study

We examined, by light and electron microscopy, three cases of malignant lentigo, one of which was in the vertical growth phase. The purpose of our work was to compare the diverse patterns between superficial spreading melanoma and malignant lentigo. The observations suggest the following major findings: 1) the cells of malignant lentigo differ from normal melanocytes, and in the same specimen they differ from one another; 2) in malignant lentigo, melanosomes at stage II-IV are visible; and 3) in spreading melanoma, the melanosomes do not attain complete maturation. These morphological features explain the different behaviour of these two types of tumors.