What is wrong with the failing heart?

Pathogenic anti-DNA idiotype-reactive IgG in intravenous immunoglobulin preparations

This study was addressed to explore the reactivity of natural anti-idiotypes from commercial lots of immunoglobulins to several idiotypes (Ids), usually expressed by anti-DNA molecules in lupus nephritis. Eleven intravenous immunoglobulin (IVIG) preparations and nine (three polyvalent and six hyper-immune) intramuscular IgG were investigated for specific content of anti-DNA, anti-F(ab')2 and antibodies reacting with several anti-DNA IgG Ids. Two samples (nos 6 and 11) showed high reactivity with allogeneic F(ab')2 and with F(ab')2 of myeloma proteins bearing the anti-DNA Id 3I+ and the 8.12+. Since both 3I and 8.12 Id markers are known to characterize pathogenic anti-DNA IgG in systemic lupus erythematosus (SLE), anti-Id antibodies to these markers were obtained by absorbing the IVIG samples nos 6 and 11 to Sepharose columns coupled with pooled F(ab')2 fragments of 3I(+)-F4(+)-8.12(+)-myeloma proteins. Inhibition experiments showed that anti-8.12 Id-eluted IgG induced a selective suppression of the DNA-reactive antibodies derived from patients with active lupus nephritis to their substrate, suggesting the involvement of 8.12+ molecules in the SLE glomerular damage. Since 8.12+ anti-DNA are nephritogenic antibodies, the occurrence of anti-8.12+ Id in commercial IVIG may be of potential therapeutic relevance in modulating the pathogenic SLE Id network. Previous variable results of IVIG treatment in SLE, such as resolution of proteinuria or worsening nephritis, could be related to variable enrichment of different lots of IVIG in suppressive anti-pathogenic Id antibodies.

Human lymphocyte and myocardial beta-adrenoceptors: up and down regulation

Radioreceptor assays have extended the knowledge of beta-adrenoceptor regulation. To evaluate the usefulness of this method in cardiovascular pharmacology, this study was designed to determine: (1) the correlation between beta-adrenoceptor density in human lymphocytes and myocardial cell membranes. This was achieved by using simultaneously harvested left auricles and whole blood samples in 10 patients scheduled to undergo cardiothoracic surgery. The correlation was found to be linear (r = 0.65; P less than 0.05; N = 10); (2) the changes in lymphocyte receptor density and affinity in heart failure. Lymphocytes were harvested from 6 healthy volunteers, 8 patients with moderate heart failure (NYHA class I or II) and 8 patients with severe heart failure (NYHA class III or IV). Mean densities observed were 75.6 +/- 11, 46.3 +/- 18 and 26.4 +/- 5.9 fmol/mg protein, respectively, and dissociation constants were 62.8 +/- 16; 67.8 +/- 14, and 46 +/- 26 pM. The number of receptors fell significantly from one heart failure class to that immediately above it (P less than 0.01; N = 22); (3) the beta-adrenoceptor regulatory properties of a class I antiarrhythmic drug, propafenone, the chemical structure of which is similar to that of the beta-blocking drug propranolol. Five patients needing antiarrhythmic treatment were given 10 d of oral propafenone treatment (450-900 mg/day). Mean adrenoceptor densities (Bmax) were 22.7 +/- 9 and 43.7 +/- 9 fmol/mg protein, and dissociation constants (KD) values were 24.7 +/- 20 and 27 +/- 18 pM respectively, before and after 10 d of chronic treatment. The number of receptors increased significantly after 10 d of treatment (P less than 0.01; N = 5).(ABSTRACT TRUNCATED AT 250 WORDS)

Congestive heart failure

Congestive heart failure (CHF) is not a single entity but a symptom complex that may represent the consequence of mechanical abnormalities, myocardial abnormalities, and/or disturbances of cardiac rhythm. In turn, it affects virtually every organ system in the body. This review focuses on CHF due to systolic dysfunction of the left ventricle, which comprises the majority of cases of this condition. Recent data suggest that CHF may be the most frequent primary diagnosis in patients on medical services in nonmilitary hospitals in this country: it affects approximately 2% of the United States population, or some 4 million people. The mortality rate for CHF is also worse than for many forms of cancer; thus, new therapeutic alternatives are imperative. In order to devise new therapeutic strategies, a detailed understanding of the pathophysiology of this condition is required. The relative advantages and disadvantages of various pharmacologic and nonpharmacologic approaches are considered in detail. Certain medications, such as the angiotensin converting enzyme (ACE) inhibitors, have been shown to improve survival, and heart transplantation is clearly life-saving for those who are eligible for this therapy. However, the real challenge is to devise strategies to prevent the occurrence of heart failure, or interrupt its progress at a very early stage.

Beta-blockers in congestive cardiomyopathy. Conceptual advance or contraindication?

The precise role of adrenergic activity in congestive cardiomyopathy has not been established. A number of mechanisms through which increased catecholamine levels may be harmful, along with the clinical and experimental evidence supporting this concept, are summarized in this review. In this context, the suggestion that beta blockers may be beneficial for patients with severe heart failure, despite their well-known propensity to decrease cardiac contractility, can be better understood. Published reports on the use of beta blocker therapy for congestive cardiomyopathy now include approximately 200 patients, but have yielded inconsistent results. Non-randomized trials in Sweden have suggested increased survival, with most patients having improved functional status while receiving beta blockade, although improvement may take three to six months to become evident. The Swedish group also reported clinical deterioration after discontinuation of beta blockade. Two recent randomized trials in America yielded promising results, but the unexpectedly low mortality in the placebo groups emphasizes the critical importance of concurrent controls. Unfavorable reports have involved small groups with short-duration therapy. Even in these reports, overt aggravation of clinical heart failure has been quite infrequent but sometimes profound. As large scale trials are undertaken, an obvious goal is the development of methods to differentiate the patients with congestive cardiomyopathy who will benefit in response to beta blocker therapy from the few patients who will have a serious adverse response.