Increased RBC autoantibody production in pregnancy.

BACKGROUND: Autoimmunization against RBCs is generally believed to occur very rarely during pregnancy and to represent a high risk for those affected. The occurrence of benign RBC autoantibodies in pregnancy is reported. STUDY DESIGN AND METHODS: The incidence of autoantibodies to RBCs in unselected pregnant and nonpregnant women were compared by the new standard gel hemagglutination method. RESULTS: Data from a total of 22,782 pregnant and 12,903 nonpregnant women were analyzed. The antibody screen test was positive in 547 (2.40%) of the pregnant women. The positive test results were related to passive anti-D in 341 cases (1.50%), to clinically relevant alloantibodies in 43 cases (0.19%), to clinically irrelevant antibodies in 138 cases (0.61%), to autoantibodies in 23 cases (0.1%), and to autoantibodies plus alloantibodies in 2 cases (0.01%). In the cases of alloantibodies and/or autoantibodies, the DAT was invariably positive with anti-C3d and less commonly so with anti-IgG. The autoantibodies were first detected during pregnancy, they predominantly reacted with enzyme-treated RBCs, and none of the affected women or their infants appear to have developed clinically significant hemolysis. In the control group consisting of nonpregnant female blood donors, there were 3 cases (0.02%) of clinically insignificant IgG autoantibodies. CONCLUSION: There is an increase in autoimmunization against RBCs during pregnancy. The resultant autoantibodies do not appear to cause significant RBC destruction. Further studies are required for precise characterization of this phenomenon.

Chlamydial immunoglobulin IgG and IgA antibodies in serum and semen are not associated with the presence of Chlamydia trachomatis DNA or rRNA in semen from male partners of infertile couples.

The role of Chlamydia (C.) trachomatis in male infertility is controversial. The objective of this study was to determine the prevalence of asymptomatic C. trachomatis infections in male partners of infertile couples, and to compare this result with the presence of chlamydial antibodies in serum and semen. C.trachomatis was detected in five of 50 semen specimens (10%) by either polymerase chain reaction for C. trachomatis DNA or direct DNA probing for C. trachomatis rRNA. There was no association between the detection of C. trachomatis in semen and the presence of chlamydial antibodies in serum or semen. Chlamydial serum antibodies were neither associated with antiserum serum antibodies nor with pathological standard semen parameters. These results indicate that the assessment of chlamydial immunoglobulin IgG and IgA antibodies in serum or semen is of limited use in male infertility work-up, in contrast to its significance in female tubal infertility. The presence of C. trachomatis in semen emphasizes the potential risk of transmission during artificial insemination and other assisted reproductive techniques, and underlines the importance of sensitive direct detection methods in this group of patients.

Lipolytic effects of heparin and low molecular weight heparin and their importance in hemodialysis.

The incidence and the degree of uremic hypertriglyceridemia in a hemodialysis population are exacerbated by the use of UF heparin as anticoagulant therapy. This hypertriglyceridemia is associated with an increase in the levels of triglyceride-rich remnant particles that are thought to be particularly atherogenic. Since arteriosclerosis and its related diseases are the major causes of morbidity and mortality in this dialysis population, the LMW heparins with their reduced stimulation of plasma lipolytic activity may provide a clinically superior alternative to UF heparin for anticoagulation therapy in long-term hemodialysis. One may also speculate that it may be more advantageous to use LMW heparin for all long-term treatments with heparin.

[A quantitative ELISA for the measurement of class-specific anti-spermatozoa antibodies]. / Ein quantitativer ELISA zur Messung von klassenspezifischen Anti-Spermatozoen-Antikörpern.

A class-specific ELISA for the quantitative determination of anti-spermatozoal antibodies is described. The intra-assay variation at the lowest standard concentration for anti-spermatozoal-IgG- and anti-spermatozoal-IgA-specific measurements was 6%. The test possessed an inter-assay variation at the lowest standard concentration in case of the anti-spermatozoal-IgG-determination of 9% and for anti-spermatozoal-IgA-determinations of 8.5%. With this ELISA 5.7% anti-spermatozoal-IgAs and 11.3% anti-spermatozoal-IgGs were identified in sera of a group of infertile females (N = 53). A collective of anti-spermatozoal antibody positive sera, identified by an anti-spermatozoal antibody ELISA measuring total immunoglobulins was subjected to an investigation with the class-specific ELISA. The proportion of anti-spermatozoal-IgAs (54%) was significantly lower than that of anti-spermatozoal-IgAs (78%). Interestingly, no correlation was observed between the parameters IgA and IgG in antispermatozoal positive sera (r = 0.139).

Low molecular weight heparin versus standard heparin. A long-term study in hemodialysis and hemofiltration patients.

The influence of low molecular weight (LMW) heparin (Braun 21-23, Mulsungen, West Germany) and unfractionated standard heparin (SH) on blood clotting and other routine laboratory parameters was investigated in a 30 week cross-over study in 30 hemodialysis patients. The LMW heparin dose necessary (anti FXa-activity) for effective anticoagulation was two thirds of the standard heparin dose. Using these doses, both substances displayed identical antithrombotic effects. Complications were not seen in either group. PTT and thrombin time were only marginally effected by LMW heparin, whereas they were markedly prolonged by SH heparin. Factor VIII activity was significantly lower in the LMW heparin group as compared to the standard heparin group after 18, 24, and 30 weeks. Antithrombin III, fibrinogen, fibrin monomers, plasminogen, and alpha 2-antiplasmin were comparable in both groups. Creatinine, urea, hemoglobin, and hematocrit were also unchanged, excluding differences in dialysis efficacy or occult blood loss. Equal numbers of blood transfusions were necessary, but bleeding complications did not occur in either group. In conclusion, safe and effective dialysis can be performed using this low molecular weight heparin for anticoagulation in hemodialysis and hemofiltration. The possible benefits of LMW heparin (reduced frequency of bleeding, alleviation of hypertriglyceridemia) were not, however, apparent, possibly because of the short observation period and the low incidence of hemorrhagic complications in routine dialyses.

Comparison of low molecular weight heparin to standard heparin in hemodialysis/hemofiltration.

Low molecular weight (LMW) heparin has been compared to standard unfractionated (UF) heparin in hemodialysis/hemofiltration in a 12 month, randomized study. Seventy patients with end-stage chronic renal failure starting dialysis treatment were randomly assigned to one of two groups treated with either LMW or UF heparin. The LMW and UF heparin doses used produced similar plasma anti-FXa levels, and comparable antithrombotic effectiveness was observed in the two groups as reflected in similar incidences of thrombus formation in the extracorporeal circulation: 1.59% and 1.33% for LMW and UF heparin, respectively. No bleeding complications were seen with either heparin, but significantly (P less than 0.05) fewer erythrocyte concentrates were needed in the LMW heparin patients. Mean factor VIII activities had risen significantly (P less than 0.001) after 12 months in the UF heparin group, whereas they were unchanged in the LMW heparin group. A significant (P less than 0.05) increase in plasma triglycerides was observed in the UF heparin group which was attributable to six (18.8%) of the patients in this group. Triglyceride concentrations remained relatively constant in the LMW heparin group. Post-heparin lipolytic activity, and in particular hepatic lipase activity, was not stimulated to the same extent in the LMW heparin-treated patients as compared to the UF heparin group. We conclude that LMW heparin is a suitable alternative to standard UF heparin for anticoagulation in hemodialysis/hemofiltration therapy. It may offer potential advantages with regard to a lower requirement for erythrocyte concentrates and less derangement of certain metabolic parameters, such as factor VIII, triglycerides and plasma lipase activity.

Low molecular weight heparin in hemodialysis and hemofiltration patients.

Low molecular weight (LMW)-heparin was used as the sole anticoagulant during hemodialysis and hemofiltration in a pilot study on 32 patients. A LMW-heparin dose corresponding to 50% of the patients usual unfractionated, standard (UF)-heparin dose was found to produce comparable plasma heparin levels (anti-FXa-activity). No thrombosis of the extracorporal system and no bleeding complications occurred at this LMW-heparin dose. In contrast to UF-heparin, LMW-heparin produced only slight increases in PTT and thrombin time in all patients. Lipoprotein lipase was stimulated only marginally by LMW-heparin, with a correspondingly reduced release of free fatty acids. Both heparin species caused similar elevations in factor VIII and fibrin monomers, thus excluding a difference in coagulation activation. On the basis of these results, long-term studies have been started at four nephrology centers. To date, 26 patients have been treated with LMW-heparin for 6 months. A LMW-heparin dose was used that produced plasma anti-FXa-activity of 0.5 to 0.9 U/ml (initial dose: 30 to 40; dose/hr: 8 to 15 anti-FXa-units/kg body wt). PTT and thrombin time were only increased by 5 sec on average. Surprisingly, the elevated pre-dialysis levels of factor VIII and fibrin monomers decreased during this 6-month period. Bleeding complications did not occur and thrombotic complications were not observed when the anti-FXa levels were above 0.5 U/ml. LMW-heparin, therefore, appears to be a good alternative to UF-heparin for dialysis patients and may present less risk of bleeding because of its reduced effect on PTT, thrombin time, and thrombocytes.

[Alpha 1-microglobulin in the urine and serum in proteinuria and kidney insufficiency]. / Alpha-1-Mikroglobulin in Urin und Serum bei Proteinurie und Niereninsuffizienz.

Alpha-1-microglobulin (alpha-1-m) is a low molecular weight glycoprotein (mw 25-33 KD) that is filtered through the glomeruli and reabsorbed in the proximal parts of the renal tubules where it is catabolized. Normal ranges were established for alpha-1-m (100 healthy controls) in serum (20-42 mg/l) and urine (3.5-8 mg/l). Alpha-1-m was then measured in 341 urine samples whose protein pattern had been classified as "pathologic" and "normal" according to microelectrophoresis. Increased alpha-1-m concentrations were found in 266 out of 280 pathologic urines (5% false negative) and in 3 out of 61 normal urines (4% false positive). Beta-2-microglobulin (beta-2-m), total protein or protein test strips showed a poorer correlation to the electrophoretic results. Measurement of alpha-1-m is, therefore, the most sensitive of these methods for the detection of proteinuria. In 90 patients with low molecular weight proteinuria and either with or without renal insufficiency alpha-1-m concentrations were determined in both urine and serum. While all patients had elevated urinary alpha-1-m concentrations, increased serum values were only found in renal insufficiency (Ccrea less than 100 ml/min). Independently of these results, we were also able to establish that increased alpha-1-m levels are found at decreased glomerular filtration rates (Ccrea less than 70 ml/min). Pathologic alpha-1-m concentrations therefore only allow the conclusion of isolated tubular impairment when the GFR is greater than 70 ml/min.(ABSTRACT TRUNCATED AT 250 WORDS)

[Automated platelet count in thrombocytopenic patients--a comparison of methods]. / Automatisierte Thrombocytenzählung an thrombocytopenischen Patienten-Ein Methodenvergleich.

157 EDTA blood samples from thrombocytopenic patients (platelets less than 100 X 10(9)/1) were measured and the platelet counts compared using the various blood cell counters of the central laboratory, University Clinic, Göttingen. Using the H 6000, Hemalog 8 (both Technicon) and ELT-8 (Ortho Instruments), product-moment correlation coefficients (r) ranging from 0.88 to 0.92 were obtained between the different counters. The correlation coefficients of the thrombocounter (Coulter) to the other instruments were only 0.84 and 0.85. Discrepant platelet counts (difference greater than 40 X 10(9)/1) were reinvestigated using the Neubauer chamber. From a total of 354 platelet measurements, falsely high concentrations were observed only in three cases and falsely low concentrations in seven cases.

[Use of low molecular-weight heparin in hemodialysis patients]. / Anwendung von niedermolekularem Heparin bei Hämodialysepatienten.

Low-molecular-weight (LMW) heparin has been compared to standard unfractionated (UF) heparin in a total of 49 patients on hemodialysis and hemofiltration in order to determine the necessary therapeutic dose and its effect on the coagulation system. A LMW heparin dose corresponding to 50% of the normal UF heparin dose was found to produce similar plasma heparin levels (anti-FXa-U/ml) in particular on minimal heparinization. At higher doses, UF heparin produced a more marked increase in plasma-heparin than did LMW heparin. Highly significant differences were found between UF and LMW heparin in their effects on PTT and thrombin time. Partial thromboplastin time (PTT) increased under UF heparin by an average of 120 s whereas LMW heparin only produced an increase of 5-7 s. Thrombin time was increased by 250-280 s under UF heparin and by 5-8 s under LMW heparin. With this LMW heparin dose of 50% of the UF heparin dose, no thrombosis of the extracorporal system occurred and no macroscopic detectable thrombotic material was found in the dialyzers or filters. No significant differences were observed between the effects of UF and LMW heparin on Factor VIII activity and fibrin monomers, so that a difference in coagulation activation between the two heparins can be excluded. Furthermore, there were no changes in thromboplastin time according to Quick, fibrinogen, antithrombin III, plasminogen, and a2-antiplasmin.(ABSTRACT TRUNCATED AT 250 WORDS)

Structural relationships between minor and major proteins of hepatitis B surface antigen.

The minor glycoproteins from hepatitis B surface antigen, GP33 and GP36, contain at their carboxy-terminal part the sequence of the major protein P24. They have 55 additional amino acids at the amino-terminal part which are coded by the pre-S region of the viral DNA.

Safety and potency aspects in the preparation of an experimental HBsAg vaccine.

No experimental setting is available to exclude residual infectivity in HBsAg vaccines derived from human plasma. Thus, safety can be achieved only by means of their preparation. To reduce infectivity of the starting material, only plasma from healthy anti-HBe positive donors was used. In the FRG, 50% of all healthy HBsAg carriers with anti-HBe have a suitable serum level of 5 to 20 micrograms/ml. The purification procedure removed hepatitis B virus by a factor greater than 10(4). The purified product contained only the HBsAg proteins and no serum protein, as shown by SDS gel electrophoresis. The pure HBsAg was treated with formalin 1:500 at 37 degrees C for 4 days. A loss of 30 to 50% antigenicity was tolerated to achieve the highest possible destruction of known and unknown infectious agents. After inactivation, the HBsAg was bound to aluminium hydroxide gel. The gel was washed repeatedly to remove the formalin. Doses of 40 micrograms or 20 micrograms absorbed HBsAg protein were given to greater than 2500 persons without serious side effects. In greater than 97% anti-HBs was formed with a median titer of 1900 I.U./ml.

Characterization of pre-s gene products in hepatitis B surface antigen.

The 20-nm particles of hepatitis B surface antigen (HBsAg) contain two minor glycoproteins, GP33 and GP36, which are probably encoded at their 55 N-terminal amino acids by the pre-s region of the viral DNA. Their 226 C-terminal amino acids are identical to the major protein P24. The 20-nm particles contained more GP33 and GP36 when the blood had a high HBsAg concentration. They were also found in relatively high amounts in HBsAg filaments and virions. Treatment with glycosidase and trypsin showed that the mannose rich glycan and the N-terminal portion of GP33 and GP36 were exposed at the surface of the HBsAg particles. The 20-nm particles containing much GP33 and GP36 did not induce higher anti-HBs titers in guinea pigs than those particles almost devoid of them.

Specificity and localization of the hepatitis B virus-associated protein kinase.

The nature of the protein kinase (PK) which phosphorylates the core protein of hepatitis B virus in vitro was studied. The PK copurified with the core particles during rate zonal centrifugation and gel chromatography. It showed the same size heterogeneity as the core particles, which consisted of a main fraction of 28-nm particles and a subfraction of 22- to 26-nm particles. DNA-containing heavy core particles with a density of 1.33 to 1.35 g/ml and less endogenous PK than did the light cores. The phosphorylation reaction had a rapid initial phase (several minutes) and a slow but long-lasting second phase (many hours). The PK had a high affinity for ATP (KM = 0.5 mumol/liter). Only few of the several hundred P21.9 subunits in one core particle were phosphorylated in vitro. The only amino acid which was phosphorylated in vitro was serine. The resistance of the introduced phospho group against alkaline phosphatase showed that the PK acceptor, and probably the enzyme itself, was located inside the core particle.

[Preparation and testing of a hepatitis B vaccine (author's transl)]. / Herstellung und Erprobung eines Hepatitis-B-Impfstoffes.

Starting with 41.5 l of plasma from anti-HBe positive carriers of HBs antigen, 11,400 doses of a hepatitis B vaccine with 42 micrograms HBsAg-protein and 11,300 national units HBsAg activity per dose were obtained. After purification, HBsAg is obtained in 99% purity with a yield of more than 90% protein. A possible residual infectivity was inactivated by a diluted formalin solution. The infectivity test in chimpanzees confirmed the absence of infectious hepatitis viruses (HBV and nonA-nonB). In guinea pigs the immunogenicity of the vaccine was comparable to that of the reference preparation from the U.S. National Institute of Health. The presence of Al(OH)3 in the vaccine increased the anti-HBs titre by factors of 30-50. After vaccination with two doses 41 of 45 persons became anti-HBs positive, with three doses 42 of 45 persons developed anti-HBs. Median anti-HBs titre after the third doses: schedule I (three doses in intervals of 6 weeks) 427 mWHO-U/ml; schedule II (two doses at an interval of 4 weeks, third doses 4 months after the first doses) 1535 mWHO-U/ml. The vaccine was well tolerated. There were minor local reactions only.