Food anaphylaxis in antiphospholipid syndrome and thrombosis

BACKGROUND

We have observed that some cases of food anaphylaxis were followed by severe thrombosis associated to anticardiolipin antibodies. Food anaphylaxis associated with antiphospholipid syndrome has seldom been published.

OBJECTIVE

The aims were: 1) to test anticardiolipin antibodies in an important number of patients with anaphylaxis due to vegetal foods and their relationship with possible thrombosis; and 2) to study seed and fruit hypersensitivity in patients with previous thrombotic events associated with antiphospholipid antibodies (aCL).

METHODS

We included 30 patients diagnosed of thrombosis associated with aCL, 52 patients who suffered from anaphylaxis due to seeds or fruits, and 120 control patients. Haematological, cardiopulmonary vascular and rheumatologic studies had been performed as needed. In vivo and in vitro allergy tests with a large battery of vegetal allergens were carried out in all the patients. Measurement of IgG aCL antibodies and specific IgE to vegetal food was done by ELISA and CAP-FEIA (Phadia). Immunodetection and inhibitions with lipoproteins belonging to seeds were performed.

RESULTS

Seventy-five percent of the patients diagnosed as having antiphospholipid primary syndrome had specific IgE against different proteins from different vegetable allergens, most of them seeds, and clearly against lipoproteins that were also recognised by the patients with food anaphylaxis but not by the control cases. Among the patients with anaphylaxis, 28% had anticardiolipin antibodies and 17.3% thrombosis.

CONCLUSION

Our study suggests that seed lipoproteins which cause severe food anaphylaxis might have a potential role in the antiphospholipid syndrome and related thrombosis.

Impact of Acute Hepatitis A Virus (HAV) Infection on HIV Viral Load in HIV-Infected Patients and Influence of HIV Infection on Acute HAV Infection

Purpose: To assess the effect of hepatitis A virus (HAV) infection on HIV viral load (VL) and the influence of HIV on the clinical expression of HAV infection. Methods: Single-center study of 23 HIV-positive patients and 41 HIV-negative patients diagnosed with acute HAV infection during 2008-2009. The impact of HAV on HIV VL was defined as an increase of >0.5 log10 during the event, or a detectable VL for those previously suppressed patients. Results: The impact of acute HAV on VL was observed in 37.5% patients. HIV-negative patients were younger (27 vs 34 years, P < .0001), and serum transaminases levels normalized earlier than in the HIV-positive patients (121 vs 178 days, P < .05). Conclusions: Acute HAV infection may have an impact on HIV VL. The interactions between the 2 viruses may not only prolong the HAV viremia, with a potential increase in the transmission of infection, but the impact on HIV may increase the risk of HIV transmission. Studies with higher sample size are needed to confirm our results.

Short communication: contribution of the immunovirological state and traditional cardiovascular risk factors to low HDL-cholesterol in HIV patients

The prevalence of low HDL-C levels in an HIV population and its related factors was investigated. We undertook a multicenter, cross-sectional study of all HIV patients on regular follow-up in five hospitals (Southern Spain). A physical examination and fasting laboratory analysis were performed and a questionnaire about cardiovascular risk factors was provided. One thousand and seventy-two patients were included, 43.8% of whom had low HDL-C levels. The prevalence of low HDL-C was higher among patients diagnosed with AIDS, those not on antiretroviral therapy, those with a detectable HIV viral load, those with CD4 cell counts ≤350 cells/μl, smokers, and those with hypertriglyceridemia. For patients on antiretroviral therapy, the prevalence of low HDL-C was higher for those on protease inhibitors than those taking nonnucleoside reverse transcriptase inhibitors. In the multivariate analysis, low HDL-C levels were associated with tobacco use (OR 1.37, 95% CI 1.04-1.8; p = 0.04), hypertriglyceridemia (OR 2.94, 95% CI 2.2-3.8; p < 0.00001), CD4 cells count ≤350 cells/μl (OR 1.74, 95% CI 1.2-2.3; p < 0.0001), and a detectable HIV viral load (OR 1.85, 95% CI 1.3-2.5; p < 0.0001). The immunological and virological conditions, in addition to traditional cardiovascular risk factors such as tobacco use and hypertriglyceridemia, affect HDL-C levels in HIV-infected patients. For patients on antiretroviral therapy, the use of protease inhibitors is associated with a higher probability of low levels of HDL-C. Although it is not clear if the higher HDL-C levels associated with antiretroviral use are surrogates for decreased cardiovascular disease risk, this may be another reason to start antiretroviral therapy earlier.

Nitrogenase reductase: A functional multigene family in Rhizobium phaseoli

The complete coding sequence of the nitrogenase reductase gene (nifH) is present in three different regions of a Rhizobium phaseoli symbiotic plasmid. Homology between two of the regions containing nifH coding sequences extends over 5 kilobases. These in turn share 1.3 kilobases of homology with the third region. The nucleotide sequences of the three nitrogenase reductase genes were found to be identical. Site-directed insertion mutagenesis indicated that none of the three genes is indispensable for nitrogen fixation during symbiosis with Phaseolus vulgaris. This implies that at least two of the reiterated genes can be functionally expressed.

THE COMPLEMENT FIXATION TEST IN THE DIAGNOSIS OF VIRUS INFECTIONS OF THE CENTRAL NERVOUS SYSTEM

A specific complement fixation test can be obtained in various central nervous system virus infections by using as antigens emulsions of infected brain tissue, freezing and thawing the brain emulsion, and then centrifuging it in an angle head centrifuge at 3500 R.P.M. for 1 hour. The method has proved reliable in the case of rabies, St. Louis encephalitis, Japanese B encephalitis, lymphocytic choriomeningitis, Eastern equine encephalomyelitis, Western equine encephalomyelitis, louping ill, and spontaneous encephalomyelitis of mice (Theiler's disease). The specificity of the reaction, regardless of the virus involved, requires different temperatures of inactivation of the sera according to animal species: 56°C. for guinea pig, 60°C. for mouse, and 65°C. for rabbit and dog sera, all heated for 20 minutes. For human sera a temperature of inactivation of 60°C. also for 20 minutes has been adopted; at this temperature the reaction is in general specific. Complement-fixing antibodies in high titre were found in the sera of rabbits, guinea pigs, mice, and dogs immunized with rabies virus. Complement-fixing antibodies were present in high titre in sera drawn from two persons 8 years after an attack of louping ill, from five persons 2½ years after an attack of Eastern equine encephalomyelitis, and from two persons 2½ years after Western equine encephalomyelitis. In cases of St. Louis encephalitis and lymphocytic choriomeningitis, complement-fixing antibodies have been found shortly following infection but not after long periods.

Short-term antiretroviral therapy to prevent mother-to-child transmission is safe and results in a sustained increase in CD4 T-cell counts in HIV-1-infected mothers

BACKGROUND

Short-term antiretroviral therapy (START) to prevent mother-to-child transmission (MTCT) is currently recommended for all HIV-1-infected pregnant women. The objective of this study was to assess the effect on CD4 cell counts and viral load dynamics the withdrawal of START after birth could generate.

METHODS

This was a 5-year cohort study involving HIV-1-infected pregnant women who presented with CD4 counts >300 cells/microL and had received START to prevent MTCT.

RESULTS

Seventy-five pregnancies were assessed. In 24 cases, there was a history of antiretroviral therapy prior to prophylaxis. The median baseline CD4 count was 573 cells/microL. In 75% of cases, prophylaxis was started after 26.6 weeks of gestation. The median CD4 cell count increase over baseline during prophylaxis was 24.5%. In only five cases did HIV-1 viral load remain detectable during prophylaxis. After START, CD4 cell counts did not drop significantly, and the HIV-1 viral load plateau was near the baseline level. The estimated mean time for CD4 count to fall below 300 cells/microL was 3.5 years and was directly associated with high baseline CD4 cell count, as well as with CD4 increase after prophylaxis, whereas it was negatively correlated with previous use of antiretroviral (ARV) drugs and persistence of detectable HIV-1 viral load during prophylaxis.

CONCLUSIONS

A potent, well-tolerated prophylactic ARV regimen can improve CD4 cell counts during and after START. In women receiving such prophylaxis, there is a remarkable time interval for CD4 cell counts to drop to levels that indicate treatment.

Postprandial apolipoprotein B48 is associated with asymptomatic peripheral arterial disease: a study in patients with type 2 diabetes and controls

BACKGROUND

Postprandial hyperlipidemia is a common feature in type 2 diabetes; our aim was to investigate whether there is an association between subclinical peripheral arterial disease (PAD) and the levels of apolipoprotein B48, as a specific marker for postprandial lipidemia.

METHODS

We enrolled 101 patients with type 2 diabetes and 73 controls free from clinical cardiovascular disease. Main outcome measures were the presence of subclinical PAD, assessed by the ankle-brachial index, and the intestinal particles measured as the concentration of apolipoprotein B48 at fasting and 4h after a mixed breakfast.

RESULTS

No control had subclinical PAD. Of the 101 diabetic patients, 21 had subclinical PAD. The levels of apo B48, both fasting and postprandial, were only significantly raised in the diabetic patients who had PAD. The diabetic patients without vascular disease had similar concentrations of triglycerides and apo B48 to the controls. In binary logistic regression analyses, only smoking and postprandial B48 levels, in addition to diabetes, were independently associated with PAD. On the other hand, PAD but not diabetes was associated with the fasting and postprandial levels of apo B48.

CONCLUSION

Our study suggests that apolipoprotein B48 levels might be a marker of occult PAD in patients suffering from type 2 diabetes mellitus. Accordingly, subclinical PAD should be taken into account in studies on postprandial lipidemia involving patients with diabetes.

Stepped-dose versus full-dose efavirenz for HIV infection and neuropsychiatric adverse events: a randomized trial

BACKGROUND

More than 50% of patients who start efavirenz treatment develop limiting neuropsychiatric adverse events (NPAEs).

OBJECTIVE

To assess whether stepwise dosing of efavirenz decreases the incidence and severity of NPAEs while maintaining virologic efficacy.

DESIGN

Randomized, double-blind, controlled trial.

SETTING

7 HIV clinics in Spain.

PATIENTS

114 HIV-infected patients eligible for efavirenz treatment plus 2 nucleoside or nucleotide reverse transcriptase inhibitors.

INTERVENTION

Random assignment (by computer-generated sequence) to receive efavirenz, 200 mg/d on days 1 through 6, 400 mg/d on days 7 through 13, and 600 mg/d on day 14 and after, or efavirenz, 600 mg/d, from day 1. Both groups received 2 nucleoside or nucleotide reverse transcriptase inhibitors chosen by the patient's physician.

MEASUREMENTS

Neuropsychiatric symptoms and sleep quality were assessed by questionnaires at 0, 7, 14, and 30 days. The primary outcome was efavirenz-related NPAEs during the first 2 weeks, and the secondary outcome was plasma HIV RNA level at 24 weeks.

RESULTS

Compared with the stepped-dose group, the full-dose group had higher incidence and severity of dizziness (66.0% vs. 32.8%; P = 0.001), hangover (45.8% vs. 20.7%; P = 0.008), impaired concentration (22.9% vs. 8.9%; P = 0.038), and hallucinations (6.1% vs. 0%; P = 0.056) during the first week. From week 2, the incidence of efavirenz-related NPAEs was similar in both groups, although the severity was greater in the full-dose group. Virologic and immunologic efficacy seemed similar in both groups.

LIMITATIONS

The sample size was calculated on the basis of a high absolute difference in rates of efavirenz-related NPAEs between the groups. A lower absolute difference and a larger sample size could have made the differences between groups reach statistical significance beyond the first week. In addition, the sample size does not allow confirmation of similar efficacy between treatment groups.

CONCLUSION

Stepwise dose escalation of efavirenz over 2 weeks reduces the incidence and intensity of efavirenz-related NPAEs while maintaining efficacy.

PRIMARY FUNDING SOURCE

Consejería de Salud, Junta de Andalucía, Spain.

Very low prevalence and no clinical significance of occult hepatitis B in a cohort of HIV-infected patients with isolated anti-HBc seropositivity: the BHOI study

PURPOSE

Data on occult HBV infection in HIV patients are conflicting. We aimed to analyse the prevalence and clinical significance of occult hepatitis B in HIV-infected subjects.

METHOD

An open-label, cross-sectional, multicentre study including all subjects with isolated anti-HBc seropositivity from a cohort of 3,030 HIV-infected patients was undertaken. HBsAg and HBsAb were both negative in all cases, and those patients with acute or convalescent hepatitis B were excluded. HBV DNA was quantified by PCR with a detection limit of 20 IU/mL.

RESULTS

We found 5 cases (2.5%) of occult hepatitis B among 202 HIV-patients with isolated anti-HBc. The mean HBV DNA was 66 (15-112) IU/mL, none had symptomatic hepatitis, and their features, including aminotransferase levels, were similar to those without occult HBV infection.

CONCLUSIONS

Occult hepatitis due to HBV is very unusual in HIV-positive patients with isolated anti-HBc. The use of standard regimens of HAART including drugs with activity against HBV might underestimate the prevalence of occult HBV infection. These patients had a very low viral load, no identifiable risk factors, and no greater risk of hypertransaminasaemia or the development of symptomatic hepatitis.

Ant community structure in citrus orchards in the mediterranean basin: impoverishment as a consequence of habitat homogeneity

This study analyzes the structure and composition of ant communities in citrus orchards in Catalonia (northeast Spain) and compares them with the ant fauna found in natural communities of the region. In the citrus orchards considered in this study, the most abundant species were Lasius niger and Pheidole pallidula, which are behaviorally dominant species. Two other dominant species, Linepithema humile and Tetramorium caespitum, were also abundant, although only in one orchard. Species richness and diversity in the studied orchards were low compared with natural communities: although in orchards, there were few species and low diversity values, in natural communities, the number of species was higher and diversity also increased. This reduction of species richness and diversity was not modified by edge effects: only light and local differences were found between the inner part of the orchards and the orchard margins, and differences among orchards were greater than differences between inner parts and edges. The activity peaks of the different ant species actively foraging on these citrus orchards were distributed throughout the whole activity period of ants. Overall, the composition of ant communities present in the citrus orchards of this study was extremely poor. This agrees with the fact that monocultures are ecosystems associated with an inevitable loss of biodiversity and abundance of insect populations.

High seroprevalence but low incidence of HCV infection in a cohort of patients with sexually transmitted HIV in Andalusia, Spain

PURPOSE

To analyze the prevalence and the incidence of hepatitis C virus (HCV) seropositivity in sexually transmitted human immunodeficiency virus (HIV) patients.

METHODS

Observational study of 1468 sexually transmitted HIV-infected patients from 7 hospitals (Southern Spain). Characteristics of HCV cases, and incidence of HCV seroconversion was assessed.

RESULTS

Seroprevalence of HCV was 16.1%, higher among heterosexual than homosexual patients, and similar between heterosexual men and women. Seroincidence was 0.16 cases per 100 patient-years, similar between homosexual and heterosexual patients. HCV patients had a mean CD4 of 523 cells/microl, 82.0% were on highly active antiretroviral therapy (HAART), and 72.0% had undetectable HIV viral load. Serum HCV-RNA was positive in 79.0% cases, and only 16.0% had ever received HCV treatment.

CONCLUSIONS

HCV seroprevalence among sexually transmitted HIV-infected patients is more frequent than in the general population; however, incidence of HCV infection is currently low. Patients with sexually transmitted HIV coinfected with HCV have their HIV infection well controlled, but HCV infection was treated in few cases.

[First antiretroviral therapy regimen in HIV-infected patients. Durability and factors associated with therapy changes]

AIM

To analyze the durability of the first highly active antiretroviral therapy (HAART) regimen used in naïve HIV-infected patients and the factors leading to therapy changes.

METHODS

Multicenter, retrospective study of naïve HIV-infected patients from 5 hospitals in Málaga (southeast Spain), who started HAART between January 1997 and December 2003. The main outcome measure was median time to the first change in the antiretroviral regimen. A descriptive analysis was performed and Kaplan-Meier curves were used to assess durability of the first HAART used. Independent factors associated with durability were evaluated with a Cox multiple regression model.

RESULTS

A total of 603 patients started HAART, and 130 (21.6%) remained under the same treatment at the latest evaluation point. Median time on the same HAART was 17.5 months, and reached 24 months when cases of simplification or structured intermittent treatment interruption were excluded from the analysis. HAART had been interrupted in 36% by one-year of follow-up. Toxicity was the main cause of switching therapy (25%), followed by simplification (19%), and virologic failure (15%). Longer durability of HAART was observed in non-nucleoside reverse transcriptase inhibitor (NNRTI) regimens, (P < 0.046; HR, 1.58) and in those with less than 5 pills (P < 0.001; HR, 2.05).

CONCLUSION

Median durability of the first HAART was almost one year and a half, and discontinuation was mainly due to toxicity. NNRTI regimens showed longer durability, which could be attributable to a lower pill burden, at least in part.