Arthur R. Rabson

HOMOZYGOUS DEFICIENCY OF C3 IN A PATIENT WITH REPEATED INFECTIONS

Abstract A patient with striking susceptibility to infection by pyogenic organisms was found to have 1/1000th or less of the normal serum concentration of C3. Investigation of members of her family revealed many individuals, including her mother and father, with C3 levels approximately half-normal, and it seems that she is homozygous for C3 deficiency.

Clinical, hematologic, and immunologic effects of interleukin-10 in humans.

We conducted a double-blind, placebo-controlled study to investigate the safety, pharmacokinetics, and immunological properties of interleukin-10 (IL-10) administration in healthy humans. Volunteers received a single intravenous bolus injection of recombinant human IL-10 (1, 10, or 25μg/kg) or placebo. Cytokine production in whole blood and peripheral blood mononuclear cells (PBMC) was assessed before and 3, 6, 24, and 48 hr after the injection. Peak serum concentrations of IL-10 (15±1.1, 208±20.1, and 505±22.3 ng/ml) occurred after 2–5 min for 1, 10, and 25μg/kg IL-10, respectively. The terminal-phase half-life was 3.18 hr. A transient leukocytosis (24–63% above baseline) was observed 6 hr after injection, which coincided with a dose-dependent decrease (12–24%) in neutrophil superoxide generation. There was a marked inhibition (60–95%) of endotoxin-induced IL-6 production from whole blood in each group receiving IL-10. Production of IL-8 in endotoxin-stimulated blood was reduced in the 10μg/kg group. In PBMC stimulated with phytohemagglutinin and phorbol ester, there was a decrease (72–87%) in interferon-γ (IFNγ) production 6 hr after IL-10 with a return to pre-IL-10 levels after 24 hr. This reduction was only partially associated with a decrease in the number of CD2-bearing cells. We conclude that IL-10 administration into humans is without significant side effects, and a single injection reducesex vivo production of IL-6, IL-8, and IFNγ.

Rapid Detection and Species Identification of Mycobacteria in Paraffin-Embedded Tissues by Polymerase Chain Reaction

The sensitivity and specificity of the polymerase chain reaction (PCR) in the detection of mycobacteria in paraffin-embedded tissues and in crude lysates of mycobacterial cultures were assessed. Sections of formalin-fixed, paraffin-embedded tissues were deparaffinized and then subjected to a simple proteinase K and boiling lysis procedure. These preparations were used directly for PCR amplification of the 383 bp segment of the gene encoding the 65 kDa mycobacterial surface antigen. Crude lysates of mycobacteria were used as positive controls. The specificity of the PCR products was confirmed by Southern blot using a region-specific digoxigenin-labeled oligonucleotide probe and chemiluminescent detection. The 383 bp diagnostic fragment was visualized in 11 of 12 acid-fast bacilli (AFB) stain/culture-proven-positive blocks. Crude lysates of mycobacteria were detected to a sensitivity of approximately 80 organisms. Amplified fragments from paraffin-embedded tissues and mycobacterial cultures of M. tuberculosis, M. avium-intracellulare, and saprophytic mycobacteria were distinguished by digestion with Nar 1 restriction endonuclease. These results suggest that PCR amplification followed by restriction enzyme digestion of the PCR product is a rapid, specific, and highly sensitive technique for the detection and speciation of mycobacteria in paraffin-embedded tissues.

Homozygous human C3 deficiency. The role of C3 in antibody production, C-1s-induced vasopermeability, and cobra venom-induced passive hemolysis.

Studies of the family of a patient with marked deficiency of the third component of complement (C3) demonstrated that the patient was homozygous for a blank allele at the C3 locus, C3-. Metabolic studies with purified radiolabeled C3 in the patient revealed a mildly elevated fractional catabolic rate and a markedly reduced synthesis rate, consistent with a lack of C3 synthesis as the patients primary defect. There was also a mild increase in the rate of conversion of purified C3 added to her serum and incubated at 37 degrees C in vitro. Major blood group-compatible erythrocytes from a patient with paroxysmal nocturnal hemoglobinuria had the same shortened survival in the C3-deficient patient as in a normal control. Although no leukocytosis developed in the patient in spontaneous infection by pyogenic organisms, there was a normal leukocytosis in response to the injection of thyphoid vaccine. The intradermal injection of C-1s, which produces a marked increase in vasopermeability in the skin of normal subjects, produced no definite change in the patient, possibly implicating C3 or a protein in the alternative pathway as the normal mediator of this response. The patients serum exhibited near-normal immune adherence activity, confirming the lack of requirement of C3 for this function. C5 inactivation and passive hemolysis of unsensitized guinea pig erythrocytes occurred normally in C3-deficient serum on incubation with cobra venom factor, indicating that C3 is not required for these reactions. The patients humoral antibody response to both protein and carbohydrate antigens was entirely normal, making it unlikely that C3 is required for antigen processing.

Hypogammaglobulinemia in liver transplant recipients: incidence, timing, risk factors, and outcomes.

Background. Recent studies suggest a substantial incidence of posttransplant hypogammaglobulinemia and an association with infection. Methods. We conducted a retrospective analysis of immunoglobulin (Ig) G levels from blood prospectively collected during a randomized double-blind placebo-controlled trial of cytomegalovirus (CMV) immune globulin that included 146 patients who underwent liver transplantation between December 1987 and June 1990. Serum samples collected at baseline and approximately weeks 4, 8, 12, 16, 24, and 32 posttransplant were analyzed. Hypogammaglobulinemia was defined as having at least one IgG level below 560 mg/dl. A variety of variables were analyzed as potential risk factors and outcomes of hypogammaglobulinemia. Results. A total of 613 samples from 112 patients were analyzed. Twenty-nine (26%) patients had posttransplant hypogammaglobulinemia. Fourteen (12.5%) had hypogammaglobulinemia at the time of their baseline measurement. There was a strong association between hypogammaglobulinemia and both one-year (P=0.0490) and five-year mortality (P=0.0187), even when adjusted for variables known to be associated with mortality (HR for one-year mortality 3.08, confidence interval 1.20, 7.91). Risk factors for hypogammaglobulinemia included only non A/non B hepatitis and “other diagnosis” (a category made up of rare causes of liver disease). None of the infectious outcomes examined, including CMV infection, CMV disease, bacteremia or invasive fungal disease, or rejection were significantly associated with hypogammaglobulinemia. Conclusions. In orthotopic liver transplant recipients we found a 26% incidence of posttransplant hypogammaglobulinemia. Approximately half of these patients were hypogammaglobulinemic at baseline. A strong association between hypogammaglobulinemia and mortality was seen. Prospective studies are needed to further elucidate the risk factors and outcomes of posttransplant hypogammaglobulinemia.

Defective neutrophil motility in children with measles

The random migration and chemotactic ability of neutrophils from ten patients with uncomplicated measles was found to be grossly impaired when compared to a group of normal children. Chemotaxis to endotoxin activated serum and to hydrolysed casein was markedly depressed, but serum from measles patients, when activated by endotoxin, generated and chemotactic activity and did not contain leukotactic inhibitors. The defect in neutrophil motility was confirmed in vivo by abnormal Rebuck skin windows. The defect was temporary, and recovery of normal chemotaxis was observed by the eleventh day after the onset of the rash.

Homozygous C3 deficiency: Detection of C3 by radioimmunoassay

Abstract A 5 10 12 - year-old girl with recurrent infections was found to have homozygous C3 deficiency. Family studies demonstrated that the pattern of inheritance was consistent with that of an autosomal codominant trait. C3 levels have ranged from 5 mg/100 ml (electroimmunoassay) to 1.7 μg/100 ml (radioimmunoassay) 2 years later. C3 was also detected in two previous homozygous-deficient patients by radioimmunoassay. These findings suggest that an intact structural gene for C3 is present in these patients. In samples of the patients serum with a C3 level less than 3 mg/100 ml, properdin factor B conversion did not occur upon incubation with zymosan. Immune adherence was normal. The vasopermeability response following intradermal injection of C 1s was normal. The patients serum incubated with zymosan did not produce a chemotactic response of normal leukocytes. Phagocytosis of endotoxin-paraffin oil-oil red O particles by normal leukocytes was not enhanced following incubation with the patients serum. Humoral antibody response and lymphocyte number and function were normal.

Defective monocyte function in patients with systemic lupus erythematosus

Peripheral blood adherent cells from patients with systemic lupus erythematosus (SLE) were shown to have markedly reduced phagocytic activity as compared to normal adherent cells or those from non-SLE patients receiving corticosteroid therapy. Both resting and phagocytosing monocytes showed decreased hexose monophosphate shunt and glycolytic activity. Mononuclear cells from SLE patients showed grossly impaired proliferative activity after NaIO4 activation. Furthermore, addition of SLE adherent cells to normal adherent cell-depleted lymphocytes decreased [3H]thymidine incorporation of the latter cells following NaIO4 treatment. Addition of normal adherent cells to SLE lymphocytes corrected the previous defect, indicating that an adherent abnormality is responsible for the defect in SLE mononuclear cell proliferation to NaIO4 activation.

Fruit allergy: Demonstration of IgE antibodies to a 30 kd protein present in several fruits

A patient who had experienced allergic responses to various fruits developed an acute anaphylactic reaction after the ingestion of a local strain of cling peaches. The patients serum, but not control sera, contained IgE antibodies reactive to extracts from peaches, guavas, bananas, mandarins, and strawberries in an ELISA. The patients serum, however, did not demonstrate elevated levels of IgE antibodies to extracts from apples, pears, and nectarines. Adsorption of the patients serum with extracts from peaches, strawberries, and mandarins resulted in a decline of detectable IgE antibodies to these fruits. Adsorption with extracts from apples and pears had no such effect. These results demonstrate the specificity of the patients IgE antibodies to selected fruits only. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by Western blotting revealed a 30 kda of protein that was recognized by the IgE antibodies in the patients serum. This protein was not present in extracts from pears or apples. Our results highlight the importance of specific allergens in considering acute allergic reactions to individuals exhibiting sensitivity to various foods or fruits.

A double-blind study comparing monomethoxy polyethylene glycol-modified honeybee venom and unmodified honeybee venom for immunotherapy. I. Clinical results.

Thirty-five patients were allocated at random to immunotherapy (IT) in a double-blind way with either monomethoxy polyethylene glycol (mPEG)-modified honeybee venom (HBV) or HBV. The two groups were well matched regarding age, sex, skin sensitivity, HBV-specific serum IgE and IgG antibodies, and history of reactions after a field sting; mPEG-HBV-treated patients received doses that increased more steeply than doses of the HBV-treated patients. The maintenance dose of the former group (200 micrograms) was greater than that of the latter group (100 micrograms). During IT, both groups had the same frequency of local swellings after injections. Four patients receiving mPEG-HBV developed one mild systemic reaction (SR) during dose increase, whereas 10 patients receiving HBV demonstrated one or more of these reactions, compelling two patients to stop therapy. Following challenge with a honeybee sting after about 14 weeks of IT, six patients with SR were observed, four in the mPEG-HBV-treated group and two in the HBV-treated group. In the HBV-treated group, three patients were not challenged, one because of an insufficient IgG increase and two other patients because they dropped out of IT before reaching maintenance dose because of repeated SRs. Since the mPEG-HBV is extremely well tolerated during IT and the success rate is not significantly lower than with unmodified HBV, we suggest it as an attractive alternative to HBV for the treatment of HBV hypersensitivity. Increase of the maintenance dose may result in an even better clinical efficacy.