Studies of streptococcal membrane antigen--binding cells in acute rheumatic fever

Blood specimens from patients with rheumatic heart disease in both India and New Mexico were typed for the presence of B cell alloantigen 883 by use of a mouse monoclonal antibody with identical specificity to the original 883 human alloantiserum. Strong relative segregation was recorded for 883 positive B cell typing in patients with rheumatic heart disease in both geographic locations as compared with that in normal unaffected controls. In patients with acute rheumatic fever, studies of actual B-lymphocyte membrane binding by anti-883 monoclonal antibody and sonicated group A streptococcal membrane antigens showed separate but contiguous localization on isolated cell surfaces. Although physically distinct, 883 B cell alloantigen and sonicated group A streptococcal membrane antigens moved together in cell capping studies after incubation at 37 degrees C. These findings reaffirm the apparent close association between 883 B cell alloantigen and rheumatic heart disease. They also demonstrate that the B cell alloantigen 883 itself is physically distinct from but very close to sites on antigen-reactive B cells actually binding to group A streptococcal membrane antigens.     

Protective antigenic determinant of streptococcal M protein shared with sarcolemmal membrane protein of human heart

We present definitive evidence that at least one protective antigenic determinant on type 5 M protein of group A streptococci evokes antibody that is cross-reactive with human heart tissue. One of nine rabbits immunized with a peptide fragment of type 5 M protein (pep M5) produced antibody that cross-reacted by immunofluorescence with sarcolemmal membranes of human heart. The cross-reactive antibody could be removed by absorbing the antiserum with sarcolemmal membranes, types 5 and 19 streptococci, or their pepsin-extracted M proteins, but with no other serotypes tested. Although each of the pep M5 immune sera was opsonic for type 5 streptococci, only the heart-reactive antiserum opsonized type 19 streptococci. The opsonization of type 19 streptococci was abolished by absorbing the antiserum with sarcolemmal membranes isolated from human heart tissue. Purified heart-reactive antibodies eluted from sarcolemmal membranes opsonized both types 5 and 19 streptococci, indicating that the heart cross-reactive determinant of type 5 M protein is cross-protective. The cross-reactive antigen was purified by affinity chromatography from detergent extracts of sarcolemmal membranes and determined to be a complex protein composed of four subunits apparently linked by disulfide bonds.     

Immunochemical characteristics of urinary proteoses associated with streptococcal glomerulonephritis

The immunologic uniqueness of the urinary α₁-acid glycoprotein, proteose, is compared to its serum counterpart, orosomucoid. It is shown that the urinary proteins may display a patient specificity not seen in the serum proteins. The role of sialic acid and its effect on proteose immunogenicity as well as antigenicity is discussed.     

Deoxyribonucleic acid strandedness. Partial characterization of the antigenic regions binding antibodies in lupus erythematosus serum.

This study shows that tritiated thymidine labeled DNA prepared from mammalian cells by the Marmur technique is a pure preparation of nucleic acid that is composed essentially of two populations of molecules. One molecular population consists of primarily double-standed nucleic acid, while the other population is of double-stranded nucleic acid with significant single-stranded regions. The double-stranded DNA with single-stranded regions can, depending upon the length of the single strand, behave as "native" DNA or "denatured" DNA on methylated albumin kieselguhr (MAK) column chromatography, Using MAK chromatography we have separated the DNA into a saltelutable fraction composed of primarily double-stranded molecules and an alkaline-elutable fraction containing double-stranded nucleic acid with variable length, single-stranded regions. Endonuclease enzyme removal of the single-stranded regions from the alkaline fraction DNA yield nucleic acid that behaves identically to the salt elutable DNA. Exonuclease removal of the single-stranded regions suggests they are located primarily at the ends of the molecules. Our data show that the alkaline-elutable DNA differs from salt-elutable DNA only in that the former has significant single-stranded regions. Sera of patients with systemic lupus erythematosus (SLE) selected for anti-DNA by hemagglutination bind significantly less to the alkaline fraction DNA than the sale fraction DNA. This difference in binding clearly does not represent simply an affinity for double-stranded vs. single-stranded nucleic acid since the alkaline fraction DNA contains predominately double-stranded nucleic acid. A model for antibody-DNA binding is suggested from the present data and information contained in the literature.     

Unusual presentation of familial Mediterranean fever with co‐existing polyarteritis nodosa and acute post‐streptococcal glomerulonephritis

Acute post‐streptococcal glomerulonephritis (APSGN) and polyarteritis nodosa (PAN) may occur simultaneously after streptococcal infection in a child who is previously healthy but carries a Mediterranean fever (MEFV) mutation. The homozygous M694V mutation in the MEFV gene may cause an augmented response to the streptococcal infection that plays a role in the development of both clinical manifestations.     

Treatment of acute glomerulonephritis in middle-aged patients

The authors present their own experience in the management of 7 patients with acute glomerulonephritis aged over 60. The efficacy of combined therapy including heparin, disaggregants, plasmapheresis of small doses of prednisolone. They also emphasize a possibility of acute disease changing into chronic one. Peculiarities of the management of glomerulonephritis in combination with numerous concomitant diseases are described.     

Partial plasma protein replacement in therapeutic plasma exchange

We wished to determine whether subtotal replacement of protein in plasma removed at plasma exchange would be adequate to prevent hypovolemia and hypoproteinemia. Seven well nourished outpatients with chronic progressive multiple sclerosis underwent 60 plasma exchanges in which two liters of plasma were replaced with 750 ml saline followed by 1250 ml of a 5% albumin solution (62.5% albumin replacement). Total serum protein, protein electrophoresis, and immunoglobulin levels were measured before and after each exchange. Clinically, the exchanges were well tolerated. Total serum protein dropped by a mean of only 18% during the study and mean preexchange serum albumin levels were unchanged, even though immunoglobulins decreased by 57–72%. We conclude that in well nourished patients, partial albumin replacement of this magnitude is an adequate substitute for plasma removed in a plasma exchange.