CD8+,CD38+ lymphocyte percent: a useful immunological marker for monitoring HIV-1-infected patients

We investigated the relationship between three prognostic markers, CD4 lymphocyte count, serum beta2-microglobulin (beta2M) levels, and CD8+,CD38+ lymphocyte percent, and the association with the rate of development of AIDS. The markers were measured regularly throughout follow-up in 224 patients. The risk of developing AIDS during follow-up was investigated using Cox proportional hazards models. Time-updated values of the prognostic markers were used, which modelled the risk of AIDS according to the latest measurement of the marker rather than using a single value of the marker at baseline. During a median follow-up period of 13.6 months (range 0.5-31.9 months), 34 cases of AIDS occurred. In a univariate analysis, all three markers predicted the development of AIDS; a 10% increase in the percentage of CD8+ T cells expressing CD38+ resulted in an 88% increase in the risk of AIDS (95% confidence interval: 53-130%; p < 0.0001). After adjustment for the current CD4 count and beta2M, a 10% increase in the CD8+,CD38+ population was associated with a 37% increase in the risk of AIDS (95% confidence interval: 4-81%; p = 0.02). Thus, the percentage CD8+,CD38+ level predicts the development of AIDS independently of the latest CD4 count and beta2M. This assay is therefore potentially useful in conjunction with blood CD4 counts and serum beta2M levels in patient management and clinical trial design.

The Nramp1 antimicrobial resistance gene segregates independently of resistance to virulent Mycobacterium tuberculosis

Nramp1 is a recently cloned gene that is involved in resistance of mice to infection with certain microbial pathogens, including the attenuated bacillus Calmette-Guérin (BCG) strain of Mycobacterium bovis, as well as certain other mycobacteria. With a view to determining whether Nramp1 influences resistance of mice to infection with virulent M. tuberculosis, BALB/c mice homozygous for the susceptibility allele of Nramp1, and DBA/2 mice homozygous for the resistance allele, as well as their F1 and F2 progeny, were typed according to their possession of these alleles using a 'hot start' polymerase chain reaction (PCR) procedure. As assessed by the ability of the mice to survive infection, the results show that Nramp1 plays no discernible role in resistance to tuberculosis.

Increased numbers of primed activated CD8+CD38+CD45RO+ T cells predict the decline of CD4+ T cells in HIV-1-infected patients

OBJECTIVE

To look for surrogate markers in HIV-1 infection that can predict the decline of CD4+ T cells.

METHODS

Multiparameter flow cytometric analyses of CD8+ lymphocytes were performed. These cells were investigated for their expression of the activation marker CD38+ within the naive (CD45RA+) and primed (CD45RO+) subsets. Serial CD4 counts were plotted for each patient and the straight line that best fitted was obtained using least squares regression. Differences in rate of decline were tested using analysis of variance, after each patient was weighted by the reciprocal of the variance.

RESULTS

Baseline levels of percentages of CD8+CD38+ T lymphocytes predict the CD4 decline in HIV-1-infected patients. Within the CD8+ subset, the primed CD8+CD38+CD45RO+ population was responsible for this prediction. Conversely, the naive CD8+CD38+CD45RA+ population was not predictive. Patients who initially showed a percentage of CD8+CD38+ T lymphocytes above the median (> 25%) had a more marked decline in CD4+ T cells when compared to individuals with percentages of CD8+CD38+ T lymphocytes below the median value (79.3 and 21.2 x 10(6)/l mean CD4 cell decline per year, respectively). Similarly, percentages of CD8+CD38+CD45RO+ T cells above the median value (> 7%) were also associated with a more rapid decline (69.4 and 14.2 x 10(6)/l mean CD4+ cell decline per year). These results were statistically significant after adjustment for the baseline CD4 count and beta 2-microglobulin levels.

CONCLUSIONS

Percentages of activated CD8+ cells expressing CD38+ can predict the rate of decline (slope) of the CD4+ T cells. This resides in the CD45RO+ primed population. An early prediction of the CD4+ slope will allow the clinician to target treatment to those patients that are most likely to benefit.

[Splenic infarction]

A 53-year-old male suffered splenic infarction etiologically related to atrial fibrillation and non-obstructive hypertrophic cardiomyopathy. The main clinical manifestations were a one-month history of epigastric and left upper quadrant pain, with tenderness to palpation in the later zone. Laboratory tests revealed a slight leucocytosis (14.700) with left shift and a marked increase in LDH concentration (945 IU). Abdominal CAT and arteriography established the diagnosis, Echography proved normal. Patient evolution was satisfactory with conservative medical treatment. We conclude that splenic infarction should be considered in all cases of acute or chronic pain in the left hypochondrium. The diagnosis is established by CAT, arteriography and hepatosplenic gammagraphy. Medical management is initially advocated, surgery being reserved for those cases involving complications or in which diagnosis is not clear. Emphasis is placed on the main etiological, clinical, diagnostic and management characteristics of splenic infarction.

Mice that carry the resistance allele of the Bcg gene (Bcgr) develop a superior capacity to stabilize bacille Calmette-Guerin (BCG) infection in their lungs and spleen over a protracted period in the absence of specific immunity

In mice, natural resistance to infection with BCG is under the influence of an autosomal gene designated Bcg. It is shown here in agreement with others that mice that possess the dominant resistant allele of the gene (Bcgr) are more capable than mice that possess the susceptible recessive allele (Bcgs) at restricting the growth of BCG in their lungs, as well as in their spleens, during the first 20 days of infection. It is shown, in addition, that in the absence of specific immunity the resistance difference between Bcgr and Bcgs mice became much more pronounced as infection progressed beyond day 20. Whereas T cell-depleted Bcgr mice developed a capacity after day 20 to cause infection in their lungs and spleens to stabilize and plateau for at least 40 days, T cell-depleted Bcgs mice were unable to prevent infection from progressing in these organs. On the other hand, both types of T cell-depleted mice were capable of causing infection to plateau in their livers and kidneys. Moreover, this T cell-independent mechanism of resistance was essentially abolished in all organs in which it was expressed by treating the mice with hydrocortisone. In the lungs of immunocompetent Bcgs mice, failure to stabilize infection was associated with heavily infected macrophages and failure to contain BCG at original sites of infection.

Evidence inconsistent with a role for the Bcg gene (Nramp1) in resistance of mice to infection with virulent Mycobacterium tuberculosis

The superior resistance of some strains of mice over others to infection with certain intracellular pathogens, including the vaccine strain of Mycobacterium bovis, bacillus Calmette Guerin (BCG), is determined by a gene associated with a small segment of chromosome 1 designated by Ity/Lsh/Bcg locus, referred to here as the Bcg locus. DBA/2 mice containing the dominant resistant allele of the Bcg gene (Bcgr), major histocompatibility complex-compatible BALB/c mice containing the recessive susceptible allele (Bcgs), and congenic C.D2-N20 Bcgr, which are genetically the same as BALB/c mice except for possessing a small piece of DBA/2 chromosome 1 containing the Bcg locus, were used to determine whether the Bcg gene determines resistance to infection with the virulent H37Rv strain of Mycobacterium tuberculosis (Mtb). According to the survival times of Bcgr and Bcgs mice infected via either the intravenous or respiratory route, Bcgr mice proved much less, rather than more, resistant to Mtb infection than Bcgs mice. Shorter survival times of Bcgr mice were associated with an inferior capacity to control Mtb growth in their lungs and to retard the development of Mtb-induced pathology in this organ. Resistance to Mtb infection was a dominant trait in the F1 progeny of Bcgr and Bcgs mice. The results show that resistance to Mtb is not determined by the resistance allele of the Bcg gene nor by the recently isolated candidate Bcg gene Nramp1, located in the Bcg locus.

[Cerebral toxoplasmosis in AIDS patients, CT and MRI images and differential diagnostic problems]

Cranial computed-tomographies (CT) and magnetic resonance imaging (MRI) of 14 patients with AIDS and central nervous system toxoplasmosis (CNST) were reviewed. In spite of the low specificity of CT and MRI findings in CNS mass lesions of AIDS patients, there are some features which have been observed as more typical of CNST, namely: 94.9% of the lesions were round shaped and 94.5% had ring or nodular enhancement; 81.3% of the cases presented multiple lesions; 60.2% of the lesions were localized at the cerebral cortical or corticomedullary junction (100% of the cases showed at least 1 lesion in this localization); 34.6% of the lesions had less than 1cm in diameter.; on nonenhanced CT, 91.3% of the lesions were hypodense.; On T2-weighted MR images, 53.4% of the lesions had at least one hypointense zone on T2-weighted images. The existence of target-shaped lesions with hypointense centre on T2-weighted MR images (29.3% the observed lesions) is also suggestive of CNST, which, to our belief, had not been previously reported and will need confirmation with larger series. The visualization of iso/hyperdense lesions on nonenhanced CT or irregular shape lesions is uncommon in CNST. The finding of a solitary lesion, on CT or MR, it is not, by itself, a good criterion of differential diagnosis.

Aerobactin production by enterotoxigenic Escherichia coli of porcine intestine

Of 135 strains of Escherichia coli from the intestines of healthy and diseased piglets screened, 16 (12%) were positive in a bioassay for aerobactin production. Of these, 15 also carried genetic determinants for heat stable or heat labile enterotoxins.

Treatment of esophageal varices by endoscopic ligation in children

Endoscopic variceal ligation (EVL) is an alternative technique to endoscopic variceal sclerotherapy (EVS) to treat esophageal varices. This method consists of mechanical ligature and thrombosis of varices using elastic rubber rings. During an 11-month period, nine pediatric patients with esophageal varices secondary to portal hypertension were treated by EVL. Extrahepatic portal vein obstruction was the cause of portal hypertension in 5 patients and in 4 cases the cause was intrahepatic disease. The average age of the patients was 8 years (range: 2-15). Five patients had bled from esophageal varices previously. Two were actively bleeding at the time of the procedure. Endoligature was performed prophylactically in four patients. Fifty varix ligations were performed in 26 separate sessions. In children older than ten years, EVL was performed under intravenous sedation. Two mild rebleeds have occurred in this group and responded to repeated ligature. Varices were reduced in grade in all patients. Six patients achieved variceal eradication. Recurrence of varices was not encountered. No major complications occurred and there were no treatment failures. These early results suggest that endoscopic ligation is a safe and effective method for the control of esophageal varices in children.

[Importance of HDL cholesterol determination in the evaluation of coronary risk in clinical practice]

OBJECTIVE

To validate to what extent the isolated determination of total Cholesterol (TC) is effective when seeking to predict coronary risk.

DESIGN

An observational crossover study of the analytic determinations of the clinics which systematically request TC and HDL-Cholesterol (HDL)--case-finding method.

SETTING

Health Centre.

PARTICIPANTS

631 analytic determinations, with samples from people who attended a Health Centre between May and November 1992, were studied.

MEASUREMENTS AND MAIN RESULTS

As proof of certainty the Atherogenic Index (AI) was used for the relative risks (RR) of suffering a coronary event in line with the Framingham study. The confidence limits (CL) were calculated to 95% in order to quantify random error and permit comparison. On varying the cut-off points of TC the indicators changed, being more sensitive (S) and less specific (E) with the lower figures: 180 mg/dl, RR > 1, S = 97.5% (CL: 100-94.7) and E = 30.5% (36.8-24.2); RR > 2, S = 100%, E = 22.1% (26.9-17.3) and RR > 3, S = 100%, E = 20.8% (25.3-16.3). As values of TC increase, S diminishes and E increases: 250 mg/dl, RR > 1, S = 48.3% (57.2-39.4), E = 87.2% (91.8-82.6); RR > 2, S = 58.6% (76.5-40.7), E = 77.2% (82-72.4) and RR > 3, S = 63.6% (92-35.2), E = 75.3% (80.1-70.5).

CONCLUSIONS

HDL must be determined if TC is -200 mg/dl. If everyone with RR > 2 is to be detected, HDL-cholesterol from TC > or = 180 mg/dl must be measured.

Liver transplantation in patients with Budd-Chiari syndrome

Patients with Budd-Chiari syndrome (obstruction of the hepatic veins) and associated hepatic insufficiency may be candidates for orthotopic liver transplantation (OLT). In our series of 405 OLT patients, 3 were transplanted due to Budd-Chiari syndrome (0.7%). The indication for liver transplantation in these patients was severe hepatic insufficiency (chronic in two and acute in the third one). Morphologic study of the obstructions revealed apparently different causes, including thrombi, membranous webs in hepatic veins, and hydatid cyst compression. The surgical technique employed in these transplantations was similar to that for other etiologies. Due to its implications for the future course of OLT, it is important to determine the exact etiology of Budd-Chiari syndrome in the pretransplant period and to treat the patients with early and long-term anticoagulant therapy to avoid syndrome recurrence.

[Does the antisecretory agent used affect the evolution of upper digestive hemorrhage?]

OBJECTIVE

To investigate whether omeprazole has improved morbidity-mortality among patients with upper gastrointestinal bleeding of non-variceal origin in comparison with ranitidine.

MATERIAL AND METHODS

Prospective, randomized and open study. We study 519 consecutive patients admitted to our Service between June 1991 and January 1993 for upper gastrointestinal bleeding of peptic origin, dividing the patients into two randomized groups that were homogeneous in terms of age, sex, previous history of gastric disease and upper gastrointestinal bleeding, intake of non-steroidal antiinflammatory drugs, and the severity of bleeding on admittance. Thus, Group A consisted of 252 patients treated immediately upon arrival at the emergency ward with 50 mg intravenous ranitidine, followed by a further 50 mg every 6 hours. Group B in turn consisted of 267 patients initially given a bolus dose of 80 mg omeprazole intravenously, followed by an additional 40 mg every 8 hours for 48 hours. Forty mg were subsequently administered every 12 hours until hospital discharge. Endoscopy was performed in all cases within the first 24 hours following admittance, those patients with active upper gastrointestinal bleeding resulted from Forrest-type ulcer of subjected to endoscopic sclerotherapy were excluded.

RESULTS

Duodenal ulcer was the most common cause of bleeding, followed by gastric ulcer and acute lesions of the mucosa. Emphasis should be placed on the high incidence of previous non-steroidal antiinflammatory drug intake in our series (54.5%). We encountered no statistically significant differences between the two groups on comparing bleeding stigmata, transfusion requirements, recurrences, emergency surgery, the duration of hospital stay, and mortality.

CONCLUSIONS

Both drugs were found to possess a similar efficacy in treating upper gastrointestinal bleeding of peptic origin.

[Smoking in Santiago, 1993-94]

The aim of this work was to study smoking habits, alcohol and drug use and living standards in a random sample of 1000 dwellings and 4700 people of Santiago through periodic surveys during 1993 and 1994. Forty nine percent of dwellings had at least one inhabitant that was a daily smoker and 73% had at least one occasional smoker. Thirty seven percent of subjects older than 15 years were smokers (40% of men and 35% of women), 27% were presumably addicted to tobacco and 16% former smokers. Alcohol abuse had a prevalence of 2.3%. The highest prevalence of smoking was noticed in low socioeconomical strata. Smoking was not related to educational level or emotional disturbances. Frequency of alcohol abuse or marihuana use was 8.8 times higher in former smokers and 25 times higher in actual smokers, compared to people that never smoked. Comparing these results with previous population surveys, the prevalence of smoking increased in the period 1971-1986 from 47 to 51% in men and from 26 to 43% in women. On the other hand, during the period 1986-1994 the prevalence decreased from 51 to 40% in men and from 43 to 35% in women.

[Prevalence of digestive symptoms in normal adult women and its association with cholelithiasis]

The aim of this work was to study the prevalence of biliary diseases and digestive symptoms in normal adult women. Four hundred nineteen women were chosen; of these 145 were discarded due to previous gastrointestinal diseases (20), previous gastrointestinal complaints (38) and previous cholecystectomy (85). Two hundred seventy six women were subjected to abdominal ultrasound examination; of these 53 had cholelithiasis and in three a gallbladder cancer was suspected (and confirmed by surgery). Considering women with previous cholecystectomy, cholelithiasis and gallbladder cancer, a 33.6% prevalence of biliary diseases can be inferred. An interrogation about gastrointestinal symptoms was performed to women subjected to ultrasound examinations, by 2 professionals unaware of ultrasound results. A high frequency of pyrosis, food intolerance and constipation was found, not observing differences between women with or without cholelithiasis. However, these last women had a higher frequency of upper abdominal pain. Both groups had also a high rate of previous surgical procedures.

[Epidemiological and etiological aspects of upper digestive hemorrhage. Multicenter study in nine Chilean hospitals (1980-1990)]

An epidemiological survey about the incidence of upper gastrointestinal bleeding during three periods (1980, 1985 and 1990), was performed in 9 Chilean hospitals. Its annual incidence decreased in 1990, when compared to 1980. Likewise the etiologies changed, with an increase in the incidence of duodenal ulcers and a decrease in the incidence of erosive gastritis and bleeding of unknown origin in 1990. A seasonal variation with higher bleeding rates in autumn was also recorded.

[Mesenteric lipodystrophy]

This case report describes the clinic and pathologic findings of an inflammatory pseudotumor of the mesentery in a 43 years old male. Previous to the hospital admission he had several episodes of intestinal occlusion and an abdominal mass. Computed tomography and mesenteric angiography were very helpful. Laboratory tests were unspecific, and the final diagnosis was obtained after surgery and histologic study of the lesion. We review published literature on inflammatory pseudotumors.