The Diagnostic Yield and Implications of Targeted Founder Pathogenic Variant Testing in an Israeli Cohort

Founder pathogenic variants (PVs) are prevalent in Israel. This study investigated the current practice of offering cancer patients two-step genetic testing, starting with targeted testing for recurring founder PVs, followed, if negative, by next-generation sequencing. A total of 2128 subjects with cancer or a positive family history underwent oncogenetic testing with a panel of 51 recurring PVs at a tertiary medical center in March 2020-January 2023. Those with a known familial PV (n = 370) were excluded from the analysis. Among the remainder, 128/1758 (7%) were heterozygous for at least one variant, and 44 (34%) carried a PV of medium-high penetrance (MHPV). Cancer was diagnosed in 1519/1758 patients (86%). The diagnostic yield of founder MHPV testing was 2% in cancer patients and 4% in healthy individuals with a positive family history. It was higher in Ashkenazi Jews than non-Ashkenazi Jews and Arabs, but not over 10% for any type of cancer, and it was significantly higher in younger (<40 years) than older (>50 years) individuals (7% vs. 1%). Eighty-four of the heterozygotes (66%), mostly Ashkenazi Jews, harbored a low-penetrance variant (LPV) not associated with the diagnosed cancer, usually APC c.3902T>A. These findings question the advantage of two-step testing. LPVs should not be included in targeted testing because this can lead to an overestimation of the yield, and their detection does not preclude further comprehensive testing.

COVID-19 in Patients with Inflammatory Bowel Disease: The Israeli Experience

Background: Crohn’s disease (CD) and ulcerative colitis (UC) are chronic, immune-mediated inflammatory bowel diseases (IBD) affecting millions of people worldwide. IBD therapies, designed for continuous immune suppression, often render patients more susceptible to infections. The effect of the immune suppression on the risk of coronavirus disease-19 (COVID-19) is not fully determined yet. Objective: To describe COVID-19 characteristics and outcomes and to evaluate the association between IBD phenotypes, infection outcomes and immunomodulatory therapies. Methods: In this multi-center study, we prospectively followed IBD patients with proven COVID-19. De-identified data from medical charts were collected including age, gender, IBD type, IBD clinical activity, IBD treatments, comorbidities, symptoms and outcomes of COVID-19. A multivariable regression model was used to examine the effect of immunosuppressant drugs on the risk of infection by COVID-19 and the outcomes. Results: Of 144 IBD patients, 104 (72%) were CD and 40 (28%) were UC. Mean age was 32.2 ± 12.6 years. No mortalities were reported. In total, 94 patients (65.3%) received biologic therapy. Of them, 51 (54%) at escalated doses, 10 (11%) in combination with immunomodulators and 9 (10%) with concomitant corticosteroids. Disease location, behavior and activity did not correlate with the severity of COVID-19. Biologics as monotherapy or with immunomodulators or corticosteroids were not associated with more severe infection. On the contrary, patients receiving biologics had significantly milder infection course (p = 0.001) and were less likely to be hospitalized (p = 0.001). Treatment was postponed in 34.7% of patients until recovery from COVID-19, without consequent exacerbation. Conclusion: We did not witness aggravated COVID-19 outcomes in patients with IBD. Patients treated with biologics had a favorable outcome.

COVID-19: minimising risk to healthcare workers during aerosol-producing respiratory therapy using an innovative constant flow canopy

Noninvasive ventilation (NIV), continuous positive airway pressure (CPAP) and high-flow nasal cannula (HFNC) can be used as the first line of treatment in coronavirus disease 2019 (COVID-19) patients with respiratory failure, postponing and maybe even avoiding the need for intubation and mechanical ventilation [1]. Recent systematic review and meta-analysis demonstrated that HFNC reduces the need for intubation compared with conventional oxygen, with no change in the death risk or length of stay in the intensive care unit [2, 3]. No direct evidence supports the use of NIV, due to a high failure rate [4]. However, when resources become limited, with no option of invasive ventilation, the use of NIV may be justified. The major caveat of using noninvasive respiratory support in the face of the COVID-19 pandemic is the generation of aerosols, composed of small virus-containing particles, which may remain suspended in the air, with increased risk for healthcare workers [5, 6]. The risk of aerosolisation depends on many variables, including duration of use, flow velocity, mask leakage and patient coughing and cooperation.

An innovative constant flow canopy enables noninvasive respiratory support with minimal risk of healthcare worker infectionhttps://bit.ly/3eqgoVZ

[A SUCCESSFUL TREATMENT OF BAROGENIC ESOPHAGEAL FISTULA WITH VACUUM-ASSISTED CLOSURE SYSTEM]

Esophageal perforation is a serious disease which entails significant morbidity and mortality. Barogenic perforation (Boerhaave's type perforation) is considered as having a relatively poor prognosis. We present a case of barogenic perforation treated initially with surgery for primary repair leading to the formation of a control fistula. The esophageal fistula was treated successfully with endoscopic vacuum-assisted closure (VAC) system therapy. This case presents a complex condition of esophageal perforation initially treated with surgery for primary repair. After surgery the patient developed a control fistula from the esophagus to the operative drain in the pleural space. We treated the fistula with a VAC (Vacuum Assisted Closure) system that was endoscopically placed in the esophagus at the level of the fistula.

Delayed Colonoscopy Following a Positive Fecal Test Result and Cancer Mortality

Background

A fecal test followed by diagnostic colonoscopy for a positive result is a widely endorsed screening strategy for colorectal cancer (CRC). However, the relationship between the time delay from the positive test to the follow-up colonoscopy and CRC mortality has not been established.

Methods

From a population-based screening program, we identified CRC patients newly diagnosed from 2005 through 2015 by a positive fecal occult test followed by a colonoscopy. The primary outcome measure was CRC-specific mortality according to four categories for the time elapsed between the positive result and the subsequent colonoscopy.

Results

The 1749 patients underwent colonoscopies within 0–3 months (n = 981, 56.1%), 4–6 months (n = 307, 17.5%), 7–12 months (n = 157, 9.0%), and later than 12 months (n = 304, 17.4%). CRC-specific deaths according to exposure groups were: 13.8% (135 of 981) for 0–3 months, 10.7% (33 of 307) for 4–6 months (crude hazards ratio [HR] = 0.74, 95% confidence interval [CI] = 0.51 to 1.14), 11.5% (18 of 157) for 7–12 months (crude HR = 0.83, 95% CI = 0.51 to 1.42), and 22.7% (69 of 304) for longer than 12 months (crude HR = 1.40, 95% CI = 1.04 to 1.90). The only variable that was associated with mortality risk was the number of positive slides (P = .003). High positivity was twice the value in the 0–3 as the longer-than-12 months group: 51.9% vs 25.0% and similar for the 4–6 and 7–12 months groups (38.1% and 36.5%), respectively. The adjusted HRs for CRC mortality were 0.81 (95% CI = 0.55 to 1.19); 0.83 (95% CI = 0.50 to 1.41), and 1.53 (95% CI = 1.13 to 2.12, P = .006) for the 4–12, 7–12, and longer-than-12-months groups, respectively, compared with the shortest delay group.

Conclusions

Among screen-diagnosed CRC patients, performance of colonoscopy more than 12 months after the initial positive fecal occult blood test was associated with more advanced disease and higher mortality due to CRC.

Antihyperglycemic therapy during colonoscopy preparation: A review and suggestions for practical recommendations

Patients with diabetes have distinct risks during precolonoscopy bowel preparation, caused by change of diet, change of antihyperglycemic medication regimens and diabetes-related complications and comorbidities. These risks include hypoglycemia, water and electrolyte imbalance, acute renal failure, lactic acidosis, ketoacidosis and low quality of bowel preparation. Here we review the existing literature and present recommendations from a subcommittee of the Israeli National Diabetes Council for primary care physicians and gastroenterologists. The instructions include general suggestions on diet and glucose monitoring and specific recommendations on timing of modification or cessation of each of the antihyperglycemic medication types to ensure patient safety during bowel preparation.

Multicenter, randomized, tandem evaluation of EndoRings colonoscopy--results of the CLEVER study

BACKGROUND AND STUDY AIMS

Adenoma miss rate during colonoscopy has become a widely acknowledged proxy measure for post-colonoscopy colorectal cancer. Among other reasons, this can happen because of inadequate visualization of the proximal aspects of colonic folds and flexures. EndoRings (EndoAid Ltd., Caesarea, Israel) is a silicone-rubber device that is fitted onto the distal end of the colonoscope. Its flexible circular rings engage and mechanically stretch colonic folds during withdrawal. The primary aim of this study was to compare adenoma miss rates between standard colonoscopy and colonoscopy using EndoRings.

METHODS

In this multicenter, randomized, tandem colonoscopy study, we performed same-day, back-to-back colonoscopies with EndoRings followed by standard colonoscopy, or vice versa.

RESULTS

After exclusion of 10 patients for protocol violations, 116 patients (38.8% female; mean age 58.7) remained for analysis. The adenoma miss rate of EndoRings colonoscopy (7/67; 10.4%) was significantly lower (P<0.001) compared with standard colonoscopy (28/58; 48.3%). Similar results were found for polyp miss rates: EndoRings (9.1%) and standard colonoscopy (52.8%; P<0.001). Mean cecal intubation times (9.3 vs. 8.4 minutes; P=0.142) and withdrawal times (7.4 vs. 7.2 minutes; P=0.286), respectively, were not significantly different between EndoRings and standard colonoscopy. Mean total procedure time was longer with EndoRings than with standard colonoscopy (21.6 vs. 18.5 minutes, P=0.001) as more polyps were removed.

CONCLUSIONS

This study demonstrates that colonoscopy with EndoRings has lower adenoma and polyp miss rates than standard colonoscopy, which may improve the efficacy particularly of screening and surveillance colonoscopies. ClinicalTrials.gov NCT01955122.

Oral administration of non-absorbable delayed release 6-mercaptopurine is locally active in the gut, exerts a systemic immune effect and alleviates Crohn's disease with low rate of side effects: results of double blind Phase II clinical trial

Therapy for Crohn's disease (CD) with thiopurines is limited by systemic side effects. A novel formulation of fixed-dose, delayed-release 6-mercaptopurine (DR-6MP) was developed, with local effect on the gut immune system and minimal absorption. The aim of this study was to evaluate the safety and efficacy of DR-6MP in patients with moderately severe CD compared to systemically delivered 6-mercaptopurine (Purinethol). Seventy CD patients were enrolled into a 12-week, double-blind controlled trial. The primary end-point was the percentage of subjects with clinical remission [Crohn's Disease Activity Index (CDAI) < 150] or clinical response (100-point CDAI reduction). Twenty-six (56·5%) and 13 (54·2%) subjects from the DR-6MP and Purinethol cohorts, respectively, completed the study. DR-6MP had similar efficacy to Purinethol following 12 weeks of treatment. However, the time to maximal clinical response was 8 weeks for DR-6MP versus 12 weeks for Purinethol. A higher proportion of patients on DR-6MP showed clinical remission at week 8. A greater improvement in Inflammatory Bowel Disease Questionnaire (IBDQ) score was noted in the DR-6MP group. DR-6MP led to a decrease of CD62(+) expression on T cells, implying a reduction of lymphocyte adhesion to site of inflammation. DR-6MP was safer than Purinethol, with significantly fewer adverse events (AEs). There was no evidence of drug-induced leucopenia in the DR-6MP group; the proportion of subjects who developed hepatotoxicity was lower for the DR-6MP. Non-absorbable DR-6MP is safe and biologically active in the gut. It is clinically effective, exerting a systemic immune response with low systemic bioavailability and a low incidence of side effects.

Standard forward-viewing colonoscopy versus full-spectrum endoscopy: an international, multicentre, randomised, tandem colonoscopy trial

BACKGROUND

Although colonoscopy is the accepted standard for detection of colorectal adenomas and cancers, many adenomas and some cancers are missed. To avoid interval colorectal cancer, the adenoma miss rate of colonoscopy needs to be reduced by improvement of colonoscopy technique and imaging capability. We aimed to compare the adenoma miss rates of full-spectrum endoscopy colonoscopy with those of standard forward-viewing colonoscopy.

METHODS

We did an international, multicentre, randomised trial at three sites in Israel, one site in the Netherlands, and two sites in the USA between Feb 1, 2012, and March 31, 2013. Patients aged 18-70 years referred for colorectal cancer screening, polyp surveillance, or diagnostic assessment underwent same-day, back-to-back tandem colonoscopy with standard forward-viewing colonoscope and the full-spectrum endoscopy colonoscope. The patients were randomly assigned (1:1), via computer-generated randomisation with block size of 20, to which procedure was done first. The endoscopist was masked to group allocation until immediately before the start of colonoscopy examinations; patients were not masked. The primary endpoint was adenoma miss rates. We did per-protocol analyses. This trial is registered with ClinicalTrials.gov, number NCT01549535.

FINDINGS

197 participants were enrolled. 185 participants were included in the per-protocol analyses: 88 (48%) were randomly assigned to receive standard forward-viewing colonoscopy first, and 97 (52%) to receive full-spectrum endoscopy colonoscopy first. By per-lesion analysis, the adenoma miss rate was significantly lower in patients in the full-spectrum endoscopy group than in those in the standard forward-viewing procedure group: five (7%) of 67 vs 20 (41%) of 49 adenomas were missed (p<0·0001). Standard forward-viewing colonoscopy missed 20 adenomas in 15 patients; of those, three (15%) were advanced adenomas. Full-spectrum endoscopy missed five adenomas in five patients in whom an adenoma had already been detected with first-pass standard forward-viewing colonoscopy; none of these missed adenomas were advanced. One patient was admitted to hospital for colitis detected at colonoscopy, whereas five minor adverse events were reported including vomiting, diarrhoea, cystitis, gastroenteritis, and bleeding.

INTERPRETATION

Full-spectrum endoscopy represents a technology advancement for colonoscopy and could improve the efficacy of colorectal cancer screening and surveillance.

FUNDING

EndoChoice.

[The use of video capsule endoscopy in diseases of the small bowel, esophagus and colon]

Capsule endoscopy has been in clinical practice for approximately a decade. The original capsule was designed for the small bowel, followed by esophageal, patency and colonic capsules. The aim of the present guidelines are to update the readers with the mode and preparations for use of the various capsules, the indications, as well as absolute and relative contraindications for their use. This document was written by the advanced technology group within the Israel Gastroenterology Association and was edited by the members of the Israel Gastroenterology Association.

Endoluminal compression clip: full-thickness resection of the mesenteric bowel wall in a porcine model

BACKGROUND

Performing a full-thickness intestinal wall resection of a sessile polyp located on the mesenteric side with a compression clip may lead to compression of mesenteric vessels. The application of such a clip may therefore cause a compromised blood supply in the particular bowel segment, leading to perforation.

OBJECTIVE

To evaluate the performance of a newly developed, nitinol compression clip, called the NiTi clamp, for full-thickness resection of the bowel wall, while the clip is deliberately deployed endoluminally on the mesenteric side.

DESIGN

Prospective animal study. Multinational, multidisciplinary; gastroenterology and general surgery, research cooperation.

SETTING

Animal research laboratory.

INTERVENTION

Six pigs were operated upon and endoscopically evaluated and then killed after 3 weeks. Linear compression closure clips based on nitinol springs were used. Three longitudinal enterotomies were performed: in the cecum, spiral colon, and proximal rectum. Four clips were deployed in each animal.

MAIN OUTCOME MEASUREMENTS

A total of 23 clips were deployed. The average expulsion day was 9 days.

RESULTS

All but 3 clips were normally expelled. One pig developed bowel ischemia due to intussusception. In endoscopic procedures, no signs of significant segmental mucosal ischemia were found. The macroscopic appearance of the compression closure lines was thin and delicate, but epithelialization was significantly delayed at 5 sites.

LIMITATION

Differences between porcine and human colorectal anatomy.

CONCLUSION

Full-thickness clamping of the bowel with the NiTi clamp, including the local mesenteric vasculature, does not significantly impair local healing of the clamp site and gives hope to further development of novel full-thickness endoscopic resection technologies.

Sightline ColonoSight system for a disposable, power-assisted, non-fiber-optic colonoscopy (with video)

BACKGROUND

The Sightline ColonoSight (CS) colonoscopy system presents 3 technologic advances: (1) disposable components protect the reusable parts from contact with colonic contents, eliminating the need for disinfection between procedures, (2) an air-pressure-powered engine assists in colonoscope advancement, (3) light emitting diode (LED) illumination eliminates the need for fiber optics and an external light source.

OBJECTIVES

To study the operation, performance, and safety of the Sightline CS colonoscopy system.

DESIGN

The system was tested during colonoscopy in animals and in human pilot studies. An in vitro dye diffusion test, and bacterial cultures (obtained after using the colonoscope in animals and humans) were performed to ascertain the protective integrity of the disposable components.

SETTING

Animal centers, hospitals in Israel and Italy, and office endoscopy centers in the United States.

PATIENTS

Thirty-three volunteers and 145 patients who required a colonoscopy for various indications.

INTERVENTIONS

Colonoscopy, polypectomy, biopsy, and coagulation.

MAIN OUTCOME MEASURES

Complications, system function, cecal intubation, and colonoscopy time.

RESULTS

The Sightline CS system performed well during a colonoscopy in 19 animals and 178 patients, without complications. Dye studies and bacterial cultures showed no transfer of dye molecules or bacterial organisms across the protective, disposable components.

LIMITATIONS

This is an observational pilot study, with no comparative group.

CONCLUSIONS

The new Sightline CS colonoscopy system performed well. The disposable components eliminated the need for disinfection of the colonoscope between procedures. Advancement of the colonoscope in the colon was helped by self propulsion of the instrument affected by an air-pressure-powered engine. LED illumination eliminated the need for fiber optics and an external light source.

Fentanyl or tramadol, with midazolam, for outpatient colonoscopy: analgesia, sedation, and safety

The present study determined the acceptability of colonoscopy in outpatients treated with tramadol or fentanyl for analgesia and sedation. One hundred fifty patients were randomly assigned to receive midazolam, 0.05 mg/kg, and fentanyl, 2 microg/kg, intravenously (group 1), midazolam, 0.05 mg/kg, and tramadol, 1 mg/kg, per os (group 2), or midazolam, 0.05 mg/kg, and tramadol, 2 mg/kg, per os (group 3). Pain severity, level of sedation, cardiorespiratory parameters, and procedure-related side effects and complications were registered and analyzed. No significant cardiorespiratory disturbances were observed. Sedation level during the procedure was similar in all groups. Pain severity values measured during the procedure was significantly higher in groups 2 and 3 than in group 1 (P < 0.001). Both hospital and home adverse events occurred more frequently in groups 2 and 3 compared to group 1 (P < 0.03). The patients receiving fentanyl-based analgesia tolerated colonoscopy better than patients treated with tramadol.

Arthritis or vasculitis as presenting symptoms of Crohn’s disease

OBJECTIVE

The aim of this study was to describe arthritis or vasculitis as initial manifestations of Crohn's disease (CD).

METHODS

We describe three cases in which the rheumatological manifestations preceded the bowel disease and one with rheumatological manifestation and asymptomatic gut inflammation. The information on clinical manifestations, laboratory examination results, imaging procedures, and histological data were gathered from the patients' medical charts. A MEDLINE search for the associations of extraintestinal manifestations of inflammatory bowel disease was performed.

RESULTS

Arthritis or vasculitis preceded the bowel disease by 3 to 15 months. In one case, the bowel disease remained asymptomatic throughout the follow-up period.

CONCLUSION

Rheumatological presentations of CD such as arthritis and vasculitis are uncommon. The diagnosis of CD without evident bowel symptoms might offer explanations and treatment options for puzzling symptoms and signs. Recognition, early diagnosis, and treatment of the underlying gut disease might prove useful for both the bowel disease and the rheumatological manifestations.

Treatment of chronic hepatitis B virus infection via oral immune regulation toward hepatitis B virus proteins

OBJECTIVES

Hepatitis B virus (HBV) is a noncytopathic virus, and hepatocellular injury is mediated by a defective host antiviral immune response. We have previously shown that antiviral immunity can be modulated through oral feeding of viral proteins. The aims of this study were to determine the safety and efficacy of treatment of patients with chronic HBV by means of p.o. administration of HBV envelope proteins.

METHODS

A total of 42 chronic HBV patients were treated p.o. with HBV envelope proteins (HBsAg+preS1+preS2), three times/wk for 20-30 wk, and followed for an additional 20 wk. Patients were monitored for HBV-DNA levels, liver enzymes, and liver histology. HBV-directed T cell immune modulation was assessed in vitro by HBV specific T cell-proliferation, cytotoxicity, IFN gamma, and IL10 ELISPOT assays, and reverse transcription-polymerase chain reaction cytokines assay.

RESULTS

Favorable response in one of the primary endpoints was achieved in 28/42 patients (66.6%) by means of p.o. immune regulation. A significant decrease in viral load was observed in 15 patients (35.7%). HBsAg/HBcAg biopsy scores improved in 41% and 57.1% of patients, respectively. Histological improvement in liver necroinflammatory score was noted in 12/40 patients (30%). In all, 80% showed biochemical response. Five of 19 HBeAg positive patients (26.3%) became negative for HBeAg. A favorable augmentation in anti-HBV specific T cell response, with increased HbsAg specific T cell proliferation (78%), cytotoxicity (75%), and IFN gamma positive T cell clones (62.9%) was noted. In addition, a decrease in the IL10 gamma positive T cell clones was achieved (48.1%). Natural killer T (NKT) lymphocytes increased significantly in all treated patients.

CONCLUSIONS

Immune regulation of the anti-HBV immune response via p.o. administration of HBV envelope proteins alleviated the immune-mediated liver injury while augmenting the effective antiviral immunity.

[Primary gastric tuberculosis]

Intestinal tuberculosis (TB) comprises 5% of all cases of TB and may be a major problem in immigrant communities, although the incidence of pulmonary TB is declining. Gastric TB is rare, constituting 0.1-2% of all cases of TB. Gastric TB usually develops secondary to other tuberculous lesions, most commonly pulmonary. On endoscopy antral infiltrative lesions are found. Primary gastric TB is very rare, only 8 cases having been reported in the English literature. We report a case of primary gastric TB in a 55-year-old woman who presented with abdominal pain and gastric outlet obstruction. The diagnosis was confirmed by endoscopic biopsies which showed granulomas, but no acid-fast bacilli. The Mantoux test was positive, acid-fast bacilli were found in the gastric juice, and a positive culture for TB was obtained on gastric lavage. There was an excellent response to antituberculous chemotherapy. With the relative rate of extra-pulmonary TB increasing, primary gastric TB should be taken into account in the differential diagnosis of infiltrative lesions of the antrum.

Prevalence of markers of infection with hepatitis B and C viruses in immigrants of operation Solomon, 1991

Sera of 200 recent Ethiopian immigrants (less than 1 year in Israel) were tested for the presence of antibodies against hepatitis B and hepatitis C viruses. The prevalence of the various markers was: anti-hepatitis B core antigen (anti-HBc) 52%, and hepatitis B surface antigen (HBsAg) 11.5%. None of the HBs-positive sera tested positive for IgM-anti core. Sixty-eight sera from nonvaccinated subjects were tested for anti-HBs, and 12 of them were anti-HBc negative/anti-HBs positive (the only positive marker was anti-HBs). Four of 23 HBsAg-positive sera were HBcAg positive (17%), and only 1 of 18 HBeAg-negative sera was positive for anti-e antibodies. Antibodies to hepatitis C were positive in 6/200 sera (3%).

Anti-histone antibodies in SLE and other autoimmune diseases

The frequency of IgG and IgM anti-total histones and anti-histone subfractions were studied in 63 patients with SLE and 257 patients with other autoimmune conditions employing the ELISA. IgG anti-histone antibodies were found in 17 of 63 (25%) sera of lupus patients and in only 16 of 257 (6%) sera of patients with other autoimmune conditions. The latter incidence did not differ statistically from that of 115 healthy control subjects. Furthermore, the concomitant appearance of both IgG and IgM anti-histone antibodies was observed only in SLE patients. Anti-histone subfraction (H1, H2A, H2B, H3, H4) activity was determined in sera containing anti-total histone antibodies. There was a higher preponderance for antibodies to H1, H2A, H2B in SLE. We conclude that anti-histone antibodies seem to be a marker for lupus and its variants (e.g. drug induced lupus) and should be routinely looked for in SLE patients.

Detection of antibodies to total histones and their subfractions in systemic lupus erythematosus patients and their asymptomatic relatives

Sera drawn from 75 patients with systemic lupus erythematosus, 141 healthy relatives (from the families of 51 patients), and 115 healthy control subjects were examined, by enzyme-linked immunosorbent assay, for IgG and IgM antibodies to total histones and their subfractions. Compared with the controls, statistically significant numbers of patients and their relatives had antihistone antibodies of both isotypes. Among the relatives, the sera from females, notably sisters of the patients, contained the highest levels of anti-total histone antibody. Anti-H2A/H2B and H3 antibodies were most prevalent among the lupus patients, but many of the relatives had IgM anti-H4 antibodies. These findings indicate that antihistone antibodies can serve as a genetic marker in patients with systemic lupus erythematosus.