Peripheral blood regulatory T cells in long-term kidney transplant recipients.

Regulatory T lymphocytes (Treg) suppress activation of the immune system and prevent pathological autoreactivity, giving them a relevant role in transplantation. In this study, we compared the proportion of Treg in a group of kidney transplant recipients with those in a control group. We used flow cytometry and labeling with monoclonal CD4, CD25, and FoxP3 antibodies to analyze the percentage of Treg lymphocytes in peripheral blood in a group of 68 patients at more than 12 years since transplantation and in 16 untransplanted healthy controls. In addition to the laboratory determinations, we analyzed the effect of some clinical parameters on the percentage of Treg in the transplanted group with a previous history of hepatitis C virus infection and undergoing immunosuppressive treatment. The percentage of Treg levels observed in the transplanted group was significantly lower than that in the control group (1.53% vs 2.89% CD4+ T cells; P = .0022). The percentage of Treg cells was significantly lower among patients treated with mycophenolate mofetil (1.12%) than other drug combinations. We also compared the percentage of Treg between transplant recipients treated with immunosuppressive monotherapy and those treated with combined immunosuppression, observing a higher percentage among patients with monotherapy.

Longitudinal analysis of immune function in the first 3 years of life in thymectomized neonates during cardiac surgery.

The purpose of this study is to evaluate the effects of neonatal thymectomy in the functional capacity of the immune system. We selected a group of 23 subjects, who had undergone thymectomy in their first 30 days of life, during an intervention for congenital heart disease. Several parameters of the immune system were evaluated during their first 3 years of life. Lymphocyte populations and subpopulations (including naive, memory and effector subpopulations), T cell receptor (TCR) Vbeta repertoire, response of T cells following in vitro stimulation by mitogen, quantification of immunoglobulins, TCR excision circles (TRECS) and interleukin (IL)-7 were measured. We found that neonatal thymectomy produces long-term diminution in total lymphocyte counts, especially in naive CD4+ and CD8+ T cells. Additionally, TRECS were decreased, and plasma IL-7 levels increased. A statistically significant negative correlation was found between absolute CD4+ T cells and IL-7 (r = -0.470, P = 0.02). The patients did not suffer more infectious events than healthy control children, but thymectomy in neonates resulted in a significant decrease in T lymphocyte levels and TRECS, consistent with cessation of thymopoiesis. This could produce a compromise in immune function later in life, especially if the patients suffer T cell depletion and need a reconstitution of immune function.

Prevalence of micro- and macroalbuminuria in a Canarian population of type 2 diabetic patients. Relationship with blood pressure, lipid profile, obesity and metabolic control.

We performed a cross-sectional study on the prevalence of micro- and macroalbuminuria in a population of 288 Type 2 diabetic patients from Northern Gran Canaria Island (age 59 +/- 9.5, years; 48% male): 179 unselected patients referred by their family physicians, and 109 from our diabetes clinic. Sex, age, duration of diabetes and hypertension, blood pressure, body mass index, waist-hip ratio, HbA1c, creatinine, cholesterol (total and HDL), triglycerides, lipoprotein (a), and the presence of retinopathy, polyneuropathy, and coronary and cerebrovascular disease were assessed. The prevalences of micro- and macroalbuminuria were 28.5% and 11.8%. Among the patients referred by their family physicians, 32.4% were micro- and 6.1% macroalbuminuric. In our diabetes clinic, there were respectively 22% and 21% (with a higher prevalence of macroalbuminuria than in primary care, p < 0.05). Seventy-three percent were hypertensive in both settings. Prevalence was 31.5% for diabetic retinopathy, 21.0% for diabetic polyneuropathy, 8.1% for cerebrovascular disease, and 20.2% for coronary heart disease. The albumin excretion rate was significantly correlated with plasma creatinine levels, diastolic blood pressure, total cholesterol and the presence of coronary heart disease and diabetic retinopathy, but not with age, duration of diabetes or hypertension, body mass index, waist/hip ratio, glycated haemoglobin or triglycerides.

Bone mineral metabolism is normal in non-insulin-dependent diabetes mellitus.

Because of the previous controversial findings in non-insulin-dependent diabetes mellitus (NIDDM), we measured bone-mineral density (BMD) by two different methods, studied biochemical markers of bone remodeling and calciotropic hormones (parathyroid hormone and calcitonin) in women with NIDDM, and compared the results with age-matched controls. Forty-seven women with NIDDM and 252 healthy nondiabetic women as controls were recruited for this study. BMD was measured by dual X-ray absorptiometry (DEXA) and by quantitative computed tomography (QCT). Biochemical markers of bone remodeling included plasma alkaline phosphatase (AP), osteocalcin (BGP), tartrate-resistant acid phosphatase (TRAP), parathyroid hormone (PTH), calcitonin (CT), and 24-h urine calcium, hydroxyproline. Diabetic patients were more obese with a higher body-mass index (BMI) than controls. Bone mass was normal in NIDDM, both by DEXA and by QCT. Biochemical markers of bone remodeling, PTH and CT were also normal. There was no statistical correlation between bone mass and any of the other measurements studied. There is no evidence that NIDDM produces any change in bone metabolism or mass.

Anaphylaxis to subcutaneous neutral protamine Hagedorn insulin with simultaneous sensitization to protamine and insulin.

We report an insulin-treated diabetic patient who suffered, in a 2-month period, three severe anaphylactic reactions immediately after self-administered subcutaneous injections of neutral protamine Hagedorn (NPH) human recombinant-DNA insulin. These reactions consisted of local and systemic symptoms, including dyspnea and hypotension. A simultaneous sensitization to human insulin and to protamine was demonstrated, both by skin tests and by the determination of serum specific IgE. Suspecting protamine allergy, we performed a test dose to human lente insulin with perfect tolerance. After a 1-year follow-up with lente-insulin treatment, no reactions have occurred, despite treatment interruptions. Therefore, protamine IgE-mediated allergy probably caused our patient's reactions. In conclusion, protamine sensitization should be ruled out in any patient with a history of reactions to subcutaneous protamine-containing insulins, even if insulin sensitization is present.

Dopaminergic modulation of aldosterone secretion in the normal menstrual cycle.

A group of eight normotensive female volunteers with regular menstrual cycles were studied during two menstrual cycles: a control cycle and one in which they received lisuride, a D1-D2 dopamine agonist (0.025 mg/8 hr). The following tests were performed in both halves of both cycles: 1) the response of prolactin (PRL) to thyrotropin-releasing hormone (TRH) administration; 2) the response of plasma renin activity (PRA) and plasma aldosterone (PA) to furosemide for 2 hours in the upright posture; and 3) the response of PRL, PRA, PA, plasma potassium (K), and cortisol (F) to metoclopramide administration. An increased response of PRL to TRH and PA to furosemide in the upright position and to metoclopramide were found in the luteal phase of the control study (p less than 0.05). After lisuride administration, in the interphase, differences in the responses of PRL to TRH and PA to furosemide in the upright position disappeared, whereas that of PA to metoclopramide increased further. We conclude that the increase of aldosterone normally observed during the luteal phase of the menstrual cycle is at least partly conditioned by diminished dopaminergic tone and that the response of aldosterone secretion to furosemide-induced sodium depletion and its response to metoclopramide stimulation may be modulated by two different types of dopamine receptors.

Brown tumor in the palate associated with primary hyperparathyroidism.

A case of brown tumor on the hard palate associated with primary hyperparathyroidism is reported. The diagnosis was suggested by the oral findings and clinical history and confirmed by biochemical determinations. Excision of a parathyroid adenoma normalized the metabolic situation and at a one-year follow-up the palatal tumor had diminished in size and lamina dura was partially regenerated.