Biochemistry of the hypoxia-inducible factor hydroxylases

The hypoxia-inducible factors are α,β-heterodimeric transcription factors that mediate the chronic response to hypoxia in humans and other animals. Protein hydroxylases belonging to two different structural subfamilies of the Fe(II) and 2-oxoglutarate (2OG)-dependent oxygenase superfamily modify HIFα. HIFα prolyl-hydroxylation, as catalysed by the PHDs, regulates HIFα levels and, consequently, α,β-HIF levels. HIFα asparaginyl-hydroxylation, as catalysed by factor inhibiting HIF (FIH), regulates the transcriptional activity of α,β-HIF. The activities of the PHDs and FIH are regulated by O2 availability, enabling them to act as hypoxia sensors. We provide an overview of the biochemistry of the HIF hydroxylases, discussing evidence that their kinetic and structural properties may be tuned to their roles in the HIF system. Avenues for future research and therapeutic modulation are discussed.

Structure-guided optimisation of N-hydroxythiazole-derived inhibitors of factor inhibiting hypoxia-inducible factor-α

The human 2-oxoglutarate (2OG)- and Fe(ii)-dependent oxygenases factor inhibiting hypoxia-inducible factor-α (FIH) and HIF-α prolyl residue hydroxylases 1-3 (PHD1-3) regulate the response to hypoxia in humans via catalysing hydroxylation of the α-subunits of the hypoxia-inducible factors (HIFs). Small-molecule PHD inhibitors are used for anaemia treatment; by contrast, few selective inhibitors of FIH have been reported, despite their potential to regulate the hypoxic response, either alone or in combination with PHD inhibition. We report molecular, biophysical, and cellular evidence that the N-hydroxythiazole scaffold, reported to inhibit PHD2, is a useful broad spectrum 2OG oxygenase inhibitor scaffold, the inhibition potential of which can be tuned to achieve selective FIH inhibition. Structure-guided optimisation resulted in the discovery of N-hydroxythiazole derivatives that manifest substantially improved selectivity for FIH inhibition over PHD2 and other 2OG oxygenases, including Jumonji-C domain-containing protein 5 (∼25-fold), aspartate/asparagine-β-hydroxylase (>100-fold) and histone Nε-lysine demethylase 4A (>300-fold). The optimised N-hydroxythiazole-based FIH inhibitors modulate the expression of FIH-dependent HIF target genes and, consistent with reports that FIH regulates cellular metabolism, suppressed lipid accumulation in adipocytes. Crystallographic studies reveal that the N-hydroxythiazole derivatives compete with both 2OG and the substrate for binding to the FIH active site. Derivatisation of the N-hydroxythiazole scaffold has the potential to afford selective inhibitors for 2OG oxygenases other than FIH.

Structural basis for binding of the renal carcinoma target hypoxia-inducible factor 2α to prolyl hydroxylase domain 2

The hypoxia-inducible factor (HIF) prolyl-hydroxylases (human PHD1-3) catalyze prolyl hydroxylation in oxygen-dependent degradation (ODD) domains of HIFα isoforms, modifications that signal for HIFα proteasomal degradation in an oxygen-dependent manner. PHD inhibitors are used for treatment of anemia in kidney disease. Increased erythropoietin (EPO) in patients with familial/idiopathic erythrocytosis and pulmonary hypertension is associated with mutations in EGLN1 (PHD2) and EPAS1 (HIF2α); a drug inhibiting HIF2α activity is used for clear cell renal cell carcinoma (ccRCC) treatment. We report crystal structures of PHD2 complexed with the C-terminal HIF2α-ODD in the presence of its 2-oxoglutarate cosubstrate or N-oxalylglycine inhibitor. Combined with the reported PHD2.HIFα-ODD structures and biochemical studies, the results inform on the different PHD.HIFα-ODD binding modes and the potential effects of clinically observed mutations in HIFα and PHD2 genes. They may help enable new therapeutic avenues, including PHD isoform-selective inhibitors and sequestration of HIF2α by the PHDs for ccRCC treatment.

5-Substituted Pyridine-2,4-dicarboxylate Derivatives Have Potential for Selective Inhibition of Human Jumonji-C Domain-Containing Protein 5

Jumonji-C domain-containing protein 5 (JMJD5) is a 2-oxoglutarate (2OG)-dependent oxygenase that plays important roles in development, circadian rhythm, and cancer through unclear mechanisms. JMJD5 has been reported to have activity as a histone protease, as an Nε-methyl lysine demethylase, and as an arginine residue hydroxylase. Small-molecule JMJD5-selective inhibitors will be useful for investigating its (patho)physiological roles. Following the observation that the broad-spectrum 2OG oxygenase inhibitor pyridine-2,4-dicarboxylic acid (2,4-PDCA) is a 2OG-competing JMJD5 inhibitor, we report that 5-aminoalkyl-substituted 2,4-PDCA derivatives are potent JMJD5 inhibitors manifesting selectivity for JMJD5 over other human 2OG oxygenases. Crystallographic analyses with five inhibitors imply induced fit binding and reveal that the 2,4-PDCA C5 substituent orients into the JMJD5 substrate-binding pocket. Cellular studies indicate that the lead compounds display similar phenotypes as reported for clinically observed JMJD5 variants, which have a reduced catalytic activity compared to wild-type JMJD5.

Dimeric iodine(i) and silver(i) cages from tripodal N-donor ligands via the [N–Ag–N]+ to [N–I–N]+ cation exchange reaction

Complexation of tripodal ligands with silver(I) salts generated M3L2 cage complexes that encapsulated anions within their cavities. Subsequent [N–Ag–N]+ to [N–I–N]+ cation exchange with I2 resulted in the corresponding halogen-bonded iodine(I) cages.

Multi-centric assessment of COVID-19 immunization access and demand among undocumented migrants

Background

Marginalization of undocumented migrants raises concerns about equitable access to COVID-19 immunization. This study describes their self-perceived accessibility of and demand for COVID-19 immunization.

Methods

A multi-centric cross-sectional survey was conducted in 4 health facilities providing care to undocumented immigrants in the USA, Switzerland, Italy, and France in February-April 2021. A convenience sample of minimum 100 patients per study site was recruited. Data was collected using an anonymous structured questionnaire including demographic variables, health status, and drivers/barriers for COVID-19 immunization. Descriptive statistics were used to characterize the primary and secondary outcomes: self-perceived accessibility of and demand for COVID-19 immunization.

Results

812 migrants completed the survey (54.3% Geneva, 17.5% Baltimore, 15.5% Milan, and 12.7% Paris). 60.9% were women, the median age was 40 years old (range 17-76), and 19 nationalities were represented: 55.9% Latin America, 12.7% Africa, 11.2% Western Pacific, 7.9% Eastern Mediterranean, 7.6% Europe, 4.7% Asia. Among participants, 14.1% and 26.2% reported prior COVID-19 infection and fear of developing severe COVID-19, respectively. Underlying co-morbidities were common (29.5%). Self-perceived accessibility of COVID-19 immunization was high (86.4%), yet demand was low (41.1%) correlating with age, co-morbidity, and views on immunization which were better for immunization in general (77.3%) than immunization against COVID-19 (56.5%). Hesitancy was mostly due to fear of adverse reactions (39.2%).

Conclusions

In this multi-centric study, undocumented migrants generally believed they would access local COVID-19 immunization programs. Yet, despite positive views about immunization in general, they reported limited confidence in COVID-19 immunization and willingness to be immunized.

Key messages

Self-perceived accessibility of COVID-19 immunization is high, yet demand is limited. COVID-19 immunization campaigns may engage communities and leverage confidence in immunization in general to address concerns about COVID-19 immunization.

Asymmetric [N–I–N]+ halonium complexes

The first examples of unrestrained asymmetric silver(i) and halonium complexes have been prepared and characterised.

Poverty and immigration as a barrier to iodine intake and maternal adherence to iodine supplementation

PURPOSE

Iodine deficiency still remains a significant health issue worldwide. Pregnant and lactating women are at risk for iodine deficiency when living in mild iodine-deficient areas such as Italy. This study aims at evaluating the consumption of iodized salt, iodine-rich-foods and maternal micronutrient supplements in a group of women with limited access to the Italian National Health System.

METHODS

A cross-sectional survey was conducted among immigrant and Italian women living in poverty and referring to 40 Non-Governmental Organization throughout Italy for their health needs. 3483 women answered the ad hoc questionnaire between January 2017 and February 2018.

RESULTS

The consumption of iodized salt was very low, and even lower among immigrant women. Determinants of iodized salt consumption were the period spent in Italy for immigrant women and living in a family-type setting, parity and, particularly, the degree of education for Italian ones. 17.5% of immigrant women and 8.6% of the Italian ones reported a diagnosis of thyroid disease. 521 women, 75.4% of whom were immigrants, were pregnant or breast-feeding. The majority (57.3%) had no specific maternal supplementation.

CONCLUSIONS

Both Italian and immigrating women with a low income or without access to the public health system have a poor adherence both to the salt iodization policy and to folic acid and iodine supplements in preconception and pregnancy. They also referred a low-frequency intake of iodine-rich-foods. The identification of barriers to health care access could be useful to promote specific health interventions in this target population.

Cameron lesions: A still overlooked diagnosis. Case report and systematic review of literature

Cameron lesions are erosive-ulcerative alterations of gastric mucosa occurring in patients with large hiatal hernia, potentially causing gastrointestinal bleeding and iron deficiency anaemia. Diagnosis may be challenging, and not infrequently erosions are overlooked at endoscopy, so that repeated and unnecessary diagnostic procedures are performed, particularly in those patients with chronic anaemia. We described two peculiar cases of patients with iron deficiency anaemia in whom Cameron lesions were either overlooked or misinterpreted. By reviewing data of 22publications reporting endoscopic and clinical data of 140patients, we noted a large prevalence of females (75%). The most frequent presenting symptoms were anaemia (62%) and overt gastrointestinal bleeding (36%). Noteworthy, as many as 69% of patients underwent one or more previous upper endoscopy before diagnosis of Cameron lesion was achieved. Patients were mainly treated with proton pump inhibitor (PPI) therapy and iron supplementation. Moreover, endoscopic haemostasis was performed in 10% of case, blood transfusion was required in one third of cases, and a similar quote of patients underwent a surgical approach for hiatal hernia repair. The observation that as many as 60% patients were already receiving standard PPI therapy when diagnosis was performed would suggest that either long-term treatment with adequate dose PPI or surgical approach for hiatal hernia repair is required. In conclusion, Cameron lesion is still an overlooked diagnosis in patients with iron deficiency anaemia in whom a 5-9.2% prevalence has been reported.

Impact of primary antibiotic resistance on the effectiveness of sequential therapy for Helicobacter pylori infection: lessons from a 5-year study on a large number of strains

BACKGROUND

The increasing prevalence of strains resistant to antimicrobial agents is a critical issue in the management of Helicobacter pylori (H. pylori) infection.

AIMS

(1) To evaluate the prevalence of primary resistance to clarithromycin, metronidazole and levofloxacin (2) to assess the effectiveness of sequential therapy on resistant strains (3) to identify the minimum number of subjects to enrol for evaluating the effectiveness of an eradication regimen in patients harbouring resistant strains.

METHODS

Consecutive 1682 treatment naïve H. pylori-positive patients referred for upper GI endoscopy between 2010 and 2015 were studied and resistances assessed by E-test. Sequential therapy was offered, effectiveness evaluated and analysed.

RESULTS

H. pylori-primary resistance to antimicrobials tested was high, and increased between 2010 and 2015. Eradication rates were (estimates and 95% CIs): 97.3% (95.6-98.4) in strains susceptible to clarithromycin and metronidazole; 96.1% (91.7-98.2) in strains resistant to metronidazole but susceptible to clarithromycin; 93.4% (88.2-96.4) in strains resistant to clarithromycin but susceptible to metronidazole; 83.1% (77.7-87.3) in strains resistant to clarithromycin and metronidazole. For any treatment with a 75%-85% eradication rate, some 98-144 patients with resistant strains need to be studied to get reliable information on effectiveness in these patients.

CONCLUSIONS

H. pylori-primary resistance is increasing and represents the most critical factor affecting effectiveness. Sequential therapy eradicated 83% of strains resistant to clarithromycin and metronidazole. Reliable estimates of the effectiveness of a given regimen in patients harbouring resistant strains can be obtained only by assessing a large number of strains.

The burden of chronic noncommunicable diseases in undocumented migrants: a 1-year survey of drugs dispensation by a non-governmental organization in Italy

OBJECTIVES

This study was carried out with two objectives. The first one was to have an insight into the prevalence of chronic noncommunicable diseases (CNCD) in undocumented migrants, and the second one was to evaluate if differences existed among different ethnic groups.

STUDY DESIGN

The study is based on the collection of data on drug dispensation by a non-governmental organization (NGO) providing free medical assistance to undocumented migrants in Milan, Italy. All the prescriptions to adult subjects from January 1 to December 31 2014 (total 8438) were recorded and analyzed. All the data available for the patients receiving prescriptions (age, gender and country of birth) were also collected in anonymous form. Ethical approval for the study was given by the Ethics Committee of the NGO.

METHODS

Drugs were grouped according to the anatomical therapeutic chemical (ATC) classification and their quantities expressed as daily defined doses (DDDs)/1000 patients/day. The 56 ATC levels were divided into three groups according to their use for acute, chronic, or both acute and chronic diseases. The statistical analysis of drug dispensation was performed for the whole population and for the five ethnic groups into which it had been divided.

RESULTS

Prescription of medicines for chronic conditions was significantly greater than for acute (154.2 ± 45.9 vs 51.3 ± 18.4 DDD/1000 patients/day, P < 0.02) and for both acute and chronic conditions (57.9 ± 12.8 DDD/1000 patients/day, P < 0.02). Five ATC classes accounted for 60% of all chronic prescriptions. They were differently distributed among the five ethnic groups (e.g., Asians required more antihypertensives and antidiabetics, East Europeans required more lipid modifying drugs, antihypertensives and antithrombotics).

CONCLUSIONS

Our data show an important use of medicines for chronic diseases in a population of undocumented migrants. Though with some limitations, this could be an indicator of a high prevalence of CNCD in this population, with significant differences among different ethnic groups. This situation should be considered when planning health interventions, also in consideration of the fact that it could have an impact on European Health Services in a short time.

Drugs Delivery by Charities: A Possible Epidemiologic Indicator in Children of Undocumented Migrants

Describing the health status of a population is difficult, especially in the case of irregular migrants who are now a growing population in western Countries. Data for children of these families are almost inexistent. In the absence of databases on this peculiar pediatric population, we analyzed drugs dispensation by a major Charity to have an insight into their health needs. This observational retrospective study was carried out during the entire 2015 and enrolled 628 undocumented children. A cohort of 8438 adult patients belonging to the same ethnic groups was used for comparison. Respiratory drugs were those most commonly prescribed, followed by those for skin and ocular diseases and by those for gastrointestinal disorders. Also in adults respiratory medications were the most dispensed, but almost in equal measure than cardiovascular drugs.To our knowledge this is the first study on the health needs of undocumented children residing in a western Country. The method we used seems to be a useful method for epidemiological analysis. As could be expected, respiratory and skin diseases ranked first, possibly owing to environmental factors.

Accuracy of a new ultrafast rapid urease test to diagnose Helicobacter pylori infection in 1000 consecutive dyspeptic patients

BACKGROUND

Rapid diagnostic tools for Helicobacter pylori are important in endoscopy.

AIMS

To assess the accuracy of a new 5 min rapid urease test (UFT300, ABS Srl, Cernusco sul Naviglio, Milan, Italy) and to compare it with the 1 h Pyloritek (Serim Laboratories, Elkhart, IN, USA) and the 24 h CLO test (Kimberly-Clark Ballard Medical Products, Roswell, GA, USA).

METHOD

Consecutive dyspeptic patients referred to our unit for endoscopy were prospectively studied. All patients underwent a (13)C-urea-breath test, histology and the UFT300 (ABS Srl; Cernusco sul Naviglio, Milan, Italy). In a sub-set of patients (n = 375), two additional RUTs were performed. Patients were deemed infected if both (13)C-UBT and histology were positive. RUTs were read at 1, 5, and 60 min.

RESULTS

Of 1000 enrolled patients 45.3% were infected with H. pylori. The sensitivity of the UFT 300 was 90.3%, 94.5% and 96.2% at 1, 5 and 60 min respectively (specificity 100%). The Pyloritek and the UFT were comparable, but the CLO test was not reliable at 5 and 60 min.

CONCLUSION

The UFT 300 test is comparable to the Pyloritek test, but the CLO test is significantly less sensitive at early time points. Reading test results at 1 min may increase false negative results, thereby decreasing sensitivity.

Serum ECP and MPO are increased during exacerbations of chronic bronchitis with airway obstruction

Many studies have demonstrated that, in asthma, serum levels of eosinophil cationic protein (ECP) are related to the activity and severity of the disease and can be used to evaluate the response to steroid treatment. During exacerbations of chronic bronchitis, airway inflammation shows some features of asthmatic inflammatory processes, with recruitment of eosinophils and recovery of significant amounts of ECP in bronchial lavage fluid (BAL). Involvement of neutrophils, with high levels of myeloperoxidase (MPO), is, on the contrary, typical of this latter disease, and not shared with asthma. In spite of the information collected with BAL and bronchial biopsy studies, few data still exist on serum levels of these proteins in chronic bronchitis. The objective of this study was to assess if serum levels of ECP and MPO are specifically increased in exacerbations of chronic bronchitis, as compared to other non-asthmatic acute respiratory disturbances. Serum ECP, MPO and immunoglobulin E (IgE) levels were measured in 17 non-atopic patients with exacerbation of chronic bronchitis with airway obstruction (COPD) and in 11 control subjects seeking emergency medical treatment for unrelated acute respiratory problems. Spirometry was performed in patients able to give the necessary collaboration. All the subjects of this study were recruited from the emergency department. Both ECP and MPO were significantly increased in serum from patients with exacerbated COPD (22.2 +/- 4.1 vs 9.5 +/- 1.4 mcg/L and 853 +/- 168 vs 375 +/- 41 mcg/L) and a strong correlation existed between these two variables (r = 0.782). A further control group was made of 11 patients with stable COPD. These subjects had levels of both ECP (13.1 +/- 2.7 mcg/L) and MPO (469 +/- 71) significantly lower than patients with exacerbated disease and higher than those without COPD. We conclude that serum ECP and MPO are increased during the exacerbations of COPD. These observations can give a basis for further studies aimed to evaluate the utility of these two proteins as markers of activity and severity of COPD.

Radiological assessment of clinical staging of lung cancer

Technical details of volumetric spiral CT and high resolution CT are presented. The role of CT scan in lung cancer is discussed: confirmation of a suspected lesion, identification of an unknown one, clinical staging, planning bioptic procedures and follow-up. In clinical staging, CT scan measures tumor diameter and relationship with surrounding structures (T factor) as well as investigates about nodal status (N factor) at the hilum or in the mediastinum but the limitation is due to the difficulty of distinguish between nodal inflammatory enlargement and metastatic involvement. Moreover, CT can be extended to the upper abdomen aimed of assessing adrenals, kidneys and liver (M factor).

[Defecography by spiral computed tomography]

PURPOSE

We investigated the possible role of helical CT defecography in pelvic floor disorders by comparing our results with those of conventional defecography.

MATERIAL AND METHODS

Our series consisted of 90 patients, namely 62 women and 28 men, ranging in age 24-82 years. They were all submitted to conventional defecography, and 18 questionable cases were also studied with helical CT defecography. The conventional examination was performed during the 4 standard phases of resting, squeezing, Valsalva and straining; we used a remote-control unit. The parameters for helical CT defecography were: 5 mm beam collimation, pitch 2, 120 KV, 250 mAs and 18-20 degrees gantry inclination to acquire coronal images of the pelvic floor. The rectal ampulla was distended with a bolus of 300 mL nonionic iodinated contrast agent (dilution: 3 g/cc). The patient wore a napkin and was seated on the table, except for those who could not hold the position and were thus examined supine. Twenty-second helical scans were performed at rest and during evacuation; multiplanar reconstructions were obtained especially on the sagittal plane for comparison with conventional defecographic images.

RESULTS

An unquestionable diagnosis could be made in all the 18 patients submitted to helical CT defecography. The diagnosis was in agreement with proctology results and added new information in all cases. Sixteen patients had constipation and 2 fecal incontinence--one from rectal prolapse and the other from a rectovaginal fistula. In this latter case helical CT defecography permitted to confirm the fistula and suggest its course. One patient had a previously undetected ovarian cancer metastatic to the anterior rectal wall.

DISCUSSION AND CONCLUSIONS

Coronal helical CT defecography images permitted to map the perineal floor muscles, while sagittal reconstructions provided information on the ampulla and the levator ani. To conclude, helical CT defecography performed well in the study of pelvic floor disorders and can follow conventional defecography especially in questionable cases.

[Renal hemangiopericytoma. Anatomo-pathologic and clinico-therapeutic considerations. A case report]

The Authors report a case of renal hemangiopericytoma, whose interest is related to the extreme rarity (24 cases reported until today), its insidious growth, the late in diagnosis, its uncertain clinical-biological evolution, not always predictable. Considering chemotherapy and radiotherapy ineffectiveness, an adequate treatment for such a neoplasm requires the surgical therapy, which must be followed by a careful follow-up.

[An echocardiographic study of left ventricular diastolic function in patients with diabetes mellitus type 2]

AIM OF THE STUDY

To evaluate left ventricular diastolic function by Doppler echocardiography in patients with type 2 (non-insulin-dependent) diabetes mellitus, without coronary artery disease.

BACKGROUND

Previous studies suggest that the velocity curve obtained by Doppler echocardiography of the mitral inflow may reflect the filling pattern of the left ventricle.

METHODS AND RESULTS

To evaluate the presence of diastolic impairment of the left ventricle in diabetic patients without evidence of coronary artery disease, 30 patients with non-insulin-dependent diabetes mellitus and 20 normal control subjects underwent M-mode, two-dimensional (2-D) and Doppler echocardiography. In the group of diabetic patients (Diabetics), the peak E wave velocity was 0.70 +/- 0.11 m/sec, while in the control group (Controls) it was 1.1 +/- 0.23 m/sec (mean values, +SD, p < 0.001). The peak A wave velocity was 0.89 +/- 0.17 in Diabetics, versus 0.60 +/- 0.34 in Controls. Consequently, E/A ratio was 0.81 +/- 0.18 in Diabetics, versus 1.73 +/- 0.29 in Controls (p < 0.001). Isovolumic relaxation time was 0.08 +/- 0.021 sec in Diabetics, while in Controls it was 0.04 +/- 0.02 sec (p < 0.001). Left atrium diameter was 41 +/- 11 mm in Diabetics, and 37 +/- 4 mm in Controls (p = NS). Left ventricular volumes, ejection fraction, interventricular septal and posterior wall thickness were similar in both groups. No correlation was found between diabetes duration and diastolic function indexes. In Diabetics no correlation was found between age and E/A ratio (correlation coefficient +/- 0.11) while in Controls E/A ratio was lower in the older subjects (r = +/- 0.75). This ratio was 1.89 +/- 0.20 in Controls aged < 65 years, and 1.6 +/- 0.33 in Controls aged > or = 65 years. (p = 0.06). These data suggest that 1) E/A ratio and isovolumic relaxation time are significantly altered in non-insulin-dependent diabetic patients without coronary artery disease; 2) Doppler echocardiography is a useful technique to detect left ventricular diastolic impairment; 3) diastolic impairment seems not to correlate with disease duration; 4) systolic function is normal in our group of type 2 diabetic patients.

Symptoms of respiratory allergies are worse in subjects with coexisting food sensitization

Food sensitization was evaluated in 78 subjects with respiratory allergies, both by skin tests with commercial and fresh allergens, and by specific IgE determination. On the basis of the presence or absence of the latter the population was divided into two groups. The group with food-specific IgE showed more severe features of respiratory allergy, including a greater number of positive skin tests and specific IgE determinations, more class 3 and 4 reactions, and more symptoms. The hypothesis that early food sensitization can predispose to severe inhalant allergy is discussed.

[Prognostic meaning of the echo-dipyridamole test in recent non-Q myocardial infarct]

The aim of this study was to evaluate the usefulness of the dipyridamole-echocardiography test soon after non Q wave myocardial infarction. Forty-two consecutive patients admitted to the Coronary Care Unit for a first episode of a non Q wave myocardial infarction were enrolled. Dipyridamole-echocardiography test and exercise stress test were performed on 29/42 patients without clinical or electrocardiographic evidence of residual ischaemia, before hospital discharge (from 7 to 15 days after admission). They were followed-up for 1 to 15 months (mean 11.9) or until one of the following clinical end points occurred: recurrence of myocardial infarction, angina or cardiac death. Over a period of 4 minutes, 0.56 mg/kg of dipyridamole was infused intravenously. The test was considered positive when a new transient wall motion abnormality was confirmed by two independent observers. According to these criteria a positive test was observed in 7/29 patients (24%) and a negative one in 22/29 (76%). The exercise stress test was positive in 12/27 patients (44%). Subsequent coronary events occurred in all the patients (100%) with positive dipyridamole-echocardiography test and in 7/22 patients (32%) with negative dipyridamole-echocardiography test (p less than 0.001). Five out of the 7 patients with positive test who underwent coronary angiography showed multivessel coronary artery disease. The sensitivity, specificity and positive predictive value of dipyridamole-echocardiography test for the identification of patients at risk for subsequent coronary events were respectively 50%, 100%, 100%, while for exercise stress test these values were 83%, 86% and 75%.(ABSTRACT TRUNCATED AT 250 WORDS)

Spontaneous and pokeweed mitogen induced production of rheumatoid factor and immunoglobulins in type II essential mixed cryoglobulinaemia

In order to evaluate functional lymphocyte defects in type II essential mixed cryoglobulinaemia (EMC) in vitro production of immunoglobulins (Ig) and rheumatoid factor (RF) has been studied in basal conditions and under pokeweed mitogen (PWM) stimulation in 15 patients and in 17 control subjects. The major finding was a significantly high basal and inducible production of RF by EMC lymphocytes as compared with the RF production in controls, while synthesis of polyclonal Ig was unaffected. A good correlation existed between in vitro production and serum levels of RF. Peripheral blood SmIg+ and Ia+ cells were also significantly increased. The possibility that EMC shares some pathogenetic mechanism with rheumatoid arthritis on the one hand and with lymphoproliferative diseases on the other is considered.

Increased frequency of antibodies to ubiquitous viruses in essential mixed cryoglobulinaemia

Antibodies to ubiquitous Herpes viruses have been studied in 13 patients with type II essential mixed cryoglobulinemia (EMC), and in two different control groups. All the EMC patients had monoclonal IgM kappa in their cryoprecipitates. IgM antibodies to the viral capsid antigen (VCA) of Epstein-Barr virus (EBV) were found in the sera of 11 EMC patients but all the cryoprecipitates were negative. IgG antibodies were also present in the sera of all and in the cryoprecipitates of some patients. In contrast, the number of subjects with antibodies to Cytomegalovirus (CMV) and Hepatitis B Virus (HBV) was not higher than in controls. Possible correlations between EMC and EBV infection are discussed.

AIDS-like immunologic alterations in clinically unaffected drug users

Peripheral blood lymphocyte subpopulations (PBLS) and HLA-DR phenotype have been evaluated in 30 IV drug users who were not affected by acquired immune deficiency syndrome (AIDS). A strongly significant reduction in helper/suppressor ratio was found in these subjects as compared to the control population. When the group under study was subdivided according to the presence or absence of signs of lymphadenopathy syndrome (LAS), the apparently unaffected individuals still had significant modifications in PBLS when compared with controls. These modifications were more marked in subjects within the LAS+ subgroup, who also showed a greater DR5 frequency than those belonging to the LAS- subgroup. The authors concluded that AIDS-like laboratory alterations are present in clinically unaffected IV drug users; the possible role of DR5 in conditioning different individual susceptibility is considered.

Bacillus subtilis selectively stimulates the synthesis of membrane bound and secreted IgA

Peripheral blood lymphocyte subpopulations and IgA production in vitro have been studied in 30 elderly subjects. Fifteen patients were treated with Bacillus subtilis (Enterogermina, Midy) and 15 with a placebo preparation. At the end of the treatment, a significant increase was noticed in lymphocytes bearing membrane IgA and Ia+ cells in the group treated with Bacillus subtilis, but not in the controls. Similarly, a significantly enhanced spontaneous production of IgA in vitro was seen in the treated subjects. The relevance of these findings to the understanding of the mode of action of Bacillus subtilis and its usefulness in different immunodeficiency states is discussed.

Plasma exchange in the treatment of essential mixed cryoglobulinemia nephropathy. Long-term follow up

Plasma exchange is increasingly used for management of Essential Mixed Cryoglobulinemia. However little is known about the long term effects of this treatment. Therefore we have reviewed the clinical and laboratory data of 20 patients with type II EMC who were followed for a mean of 24 months. 16 patients had renal involvement, which was characterized histologically in all of them: 9 had diffuse proliferative GN plus endoluminal "thrombi" in 6 and vasculitis in 5, 4 had lobular membranoproliferative GN and 3 had focal proliferative GN. 14 patients had renal failure and 13 had proteinuria greater than or equal to 2 g/24 hr. PE (combined with immunosuppressive drugs in 18) was performed for a mean of 18 procedures. The combined treatment induced prompt remission of extrarenal and renal involvement. Serum creatinine and proteinuria decreased significantly in all but 2 patients during the treatment (s. creatinine from 2.9 to 1.6 mg/dl; proteinuria from 3.5 to 1.6 g/24 hr). Analysis of long term follow up revealed that these effects were long lasting in all the cases. We conclude that PE should be used for EMC nephropathy whenever prompt remission is not obtained by conventional therapy especially in consideration of its long term beneficial effects.

Immunologic and immunogenetic features of primary Kaposi's sarcoma

In order to establish if immunologic alterations seen in acquired immunodeficiency syndrome (AIDS)-associated Kaposi's sarcoma are also present in the primary form of this malignancy, peripheral blood T-lymphocyte characterization and HLA A, B, C, and DR phenotyping have been carried out in 18 patients with the primary form of the disease. HLA antigen distribution was not significantly different from that of the normal population and, in particular, DR5 was only marginally increased. The T4/T8 ratio was significantly higher in the patients than in the control group, and this was due to a marked decrease in suppressor cells. The possible pathogenetic relevance of these findings is discussed.

Significance of circulating C1q-binding activity in chronic liver disease: a study of 133 cases

Circulating immune complexes (CIC) were measured in 133 biopsy-proven patients with various liver diseases. The correlation between CIC levels and other laboratory findings was investigated in each disease group, in order to assess if the increased C1q-binding activity found in these patients was related to particular features of the disease. CIC levels were not significantly different in HBsAg-positive and HBsAg-negative patients. No correlation was found between CIC levels and serum bilirubin, AST, ALT and C3 levels. A negative correlation with C4 levels and a positive correlation with immunoglobulin levels were found in the majority of the patients, while prothrombin time and albumin levels were negatively correlated to CIC levels only in patients with chronic active hepatitis. Increased CIC levels could represent a response to gut-associated antigens, a passive accumulation due to reduced hepatic function or both.

Patterns of T cell subset alterations in myelo- and lymphoproliferative disorders

Monoclonal antibody defined peripheral blood T lymphocyte subsets have been evaluated in 61 patients with chronic haematologic malignancies (CLL, CML, Multiple Myeloma, Essential Thrombocythaemia and Mycosis Fungoides). Common patterns of alterations were evident in some groups of patients. Total T cells and helper T cells showed variable degrees of reduction in all of them, except the Mycosis Fungoides group. In CLL the decrease in total T cells was associated with an increase of cells expressing the Ia like antigen. Suppressor cells were reduced in all the groups studied, except in multiple myeloma. The possible clinical and pathogenetic relevance of these findings is discussed.

Plasma exchange in glomerulonephritis associated with systemic lupus erythematosus and essential mixed cryoglobulinemia

Intensive plasma exchange and immunosuppression have been used in 13 patients affected by severe forms of glomerulonephritis (GN) associated with systemic lupus erythematosus (SLE) and essential mixed cryoglobulinaemia (EMC). The patients were divided into two groups.

Acquisition of deoxyguanosine resistance by TPA-induced T lymphoid lines

The human leukemic T cell line 8402, which contains terminal deoxynucleotidyl transferase (TdT) and phenotypically resembles precursor thymocytes, when exposed to the phorbol ester 12-O-tetradecanoyl phorbol-13-acetate (TPA) undergoes in vitro T maturation. TdT disappears from virtually all the cells and a fraction of TdT- -cells express specific T surface markers, such as the T3 determinant. Like T lymphocytes from the thymus, 8402 cells are extremely sensitive to the cytotoxic effect of deoxyguanosine (dGuo). As a consequence of TPA treatment, resistance to dGuo is observed in 8402, as well as in two other TdT+ lymphoid T cell lines, Molt-4 and CEM-10. These results suggest the occurrence of changes in deoxynucleoside metabolism in TPA-treated cells related to the in vitro maturation process. Maturation of 8402 cells, once started, progresses in the presence of additional physiologic stimuli provided by conditioned medium from lymphocyte culture, because a portion of cells display the T8+/T4- phenotype characteristic of cytotoxic/suppressor T cells. This in vitro lymphoid system may thus be used to study the relationships of molecular differentiation between precursor thymocytes and cytotoxic/suppressor T cells.

Acquisition of deoxyguanosine resistance by TPA-induced T lymphoid lines

The human leukemic T cell line 8402, which contains terminal deoxynucleotidyl transferase (TdT) and phenotypically resembles precursor thymocytes, when exposed to the phorbol ester 12-O-tetradecanoyl phorbol-13-acetate (TPA) undergoes in vitro T maturation. TdT disappears from virtually all the cells and a fraction of TdT- -cells express specific T surface markers, such as the T3 determinant. Like T lymphocytes from the thymus, 8402 cells are extremely sensitive to the cytotoxic effect of deoxyguanosine (dGuo). As a consequence of TPA treatment, resistance to dGuo is observed in 8402, as well as in two other TdT+ lymphoid T cell lines, Molt-4 and CEM-10. These results suggest the occurrence of changes in deoxynucleoside metabolism in TPA-treated cells related to the in vitro maturation process. Maturation of 8402 cells, once started, progresses in the presence of additional physiologic stimuli provided by conditioned medium from lymphocyte culture, because a portion of cells display the T8+/T4- phenotype characteristic of cytotoxic/suppressor T cells. This in vitro lymphoid system may thus be used to study the relationships of molecular differentiation between precursor thymocytes and cytotoxic/suppressor T cells.

Monoclonal antibody-defined peripheral blood T lymphocyte subpopulations in patients with mycosis fungoides

A panel of monoclonal antibodies has been used to identify peripheral blood lymphocyte subpopulations in 13 patients with mycosis fungoides and in 13 normal subjects. An increase in the T6+ population and a decrease in the T8+ population were noticed in our patients. Their T4/T8 ratio was considerably augmented. In 4 patients reevaluated after treatment, marked changes in the relative proportions of T lymphocyte subsets had occurred. The possible pathogenetic significance of these immunological alterations is discussed.

Immunological monitoring of a patient with Guillain-Barré syndrome successfully treated with plasma exchange

A patient with Guillain-Barré syndrome was successfully treated by plasma exchange (without any other therapy), and the relationship between changes in his peripheral blood lymphocyte subpopulations and the clinical improvement induced by plasma-pheresis was studied. At the recovery, the most interesting findings were an increase in T suppressor lymphocytes, and in Fc receptor-bearing lymphocytes (above normal values), together with a decrease in B lymphocytes. In this patient, plasma exchange not only removed toxic humoral factors, but also restored a normal balance among peripheral lymphocytes.