False-positive Pregnancy Tests Research Articles

False positive pregnancy tests in pediatric patients with augmentation enterocystoplasty

Our primary aim was to determine the prevalence of positive over-the-counter (OTC) pregnancy tests among pediatric female and male patients who had undergone augmentation enterocystoplasty. A secondary aim was to determine whether patient factors or urinalysis (UA) results were associated with false positive OTC pregnancy test results in patients with a history of augmentation enterocystoplasty. Patients at a tertiary pediatric hospital who had previously undergone augmentation enterocystoplasty, Mitrofanoff appendicovesicostomy only, and age- and sex-matched controls were prospectively recruited. Urine samples were obtained, and two OTC pregnancy tests were conducted - OTC Test A reported the ability to detect pregnancy at hCG levels as low as 9.6 mIU/mL, while OTC Test B reported positive pregnancy test results at hCG levels ≥25 mIU/mL. A point of care (POC) pregnancy test and UA were also completed. Mann-Whitney U tests and Fisher's exact tests were used to assess whether patient factors or UA results were associated with false positive pregnancy test results. Fifty pediatric patients were enrolled, including 20 with augmentation enterocystoplasty, 20 age- and sex-matched controls, and 10 with Mitrofanoff appendicovesicostomy only. Among the 20 patients who had undergone augmentation cystoplasty, 15 (75.0%) had positive pregnancy test results on OTC Test A, including 11/13 (84.6%) females and 4/7 (57.1%) males. No control patients or patients with Mitrofanoff appendicovesicostomy only had a positive test. No patients had positive pregnancy test results on OTC Test B or the POC test. While patients with augmentation enterocystoplasty were significantly more likely to test positive for blood (p=0.01), nitrate (p=0.03), and leukocytes (p<0.0001), these factors were not significantly associated with false positive pregnancy results. No patient factors or UA results were associated with increased likelihood of false positive OTC pregnancy test results. These findings indicate that sensitive OTC pregnancy tests that detect low quantities of hCG in urine may result in false positive results among patients who have undergone augmentation enterocystoplasty. Female patients of reproductive age with bladder augmentations should be counseled regarding appropriate pregnancy testing options. Additional research is needed to determine the mechanism responsible for false positive pregnancy tests in this patient population.

False Positive Pregnancy Test Before Kidney Transplant: Case Report and Review of Literature

Pregnancy tests are routinely done before any surgery under general anesthesia including kidney transplantation. Positive test usually leads to more investigations to detect a possible pregnancy or malignancy and the surgery gets canceled or postponed. Because a kidney transplant from a deceased donor is not elective, it usually gets canceled in this scenario. Some groups have reported on normally elevated human chorionic gonadotrophin (hCG) levels in perimenopausal women and in patients with chronic kidney disease. This is thought to be from the pituitary. We present a highly sensitized prospective kidney transplant recipient with a positive pregnancy test with low levels of serum human chorionic gonadotrophin. She underwent additional preoperative testing after which we proceeded with the kidney transplant. Herein, we discuss the management of patients who have an unexpected positive pregnancy test before transplant.

MP11-03 FALSE POSITIVE PREGNANCY TESTS AMONG PEDIATRIC PATIENTS WITH AUGMENTATION ENTEROCYSTOPLASTIES

You have accessJournal of UrologyCME1 May 2022MP11-03 FALSE POSITIVE PREGNANCY TESTS AMONG PEDIATRIC PATIENTS WITH AUGMENTATION ENTEROCYSTOPLASTIES Zoë Baker, Arthi Hannallah, Hannah Dillon, Yuding Wang, and Evalynn Vasquez Zoë BakerZoë Baker More articles by this author , Arthi HannallahArthi Hannallah More articles by this author , Hannah DillonHannah Dillon More articles by this author , Yuding WangYuding Wang More articles by this author , and Evalynn VasquezEvalynn Vasquez More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002533.03AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: A high number of false positive pregnancy test results have been self-reported among patients with augmentation enterocystoplasties using over-the-counter (OTC) urine pregnancy tests. We sought to determine the accuracy of OTC pregnancy tests among pediatric patients who had previously undergone augmentation enterocystoplasties. METHODS: Patients at a tertiary care pediatric hospital who had previously undergone augmentation enterocystoplasties or Mitrofanoff appendicovesicostomies only were prospectively recruited. Urine samples were obtained and two OTC pregnancy tests, one point of care testing (POCT) urine pregnancy test, and urinalysis (UA) were completed. All pregnancy tests qualitatively assessed human chorionic gonadotropin (hCG). OTC Test A was a sandwich immunoassay employing monoclonal anti-β-hCG, goat anti-rabbit, anti-α-hCG, and rabbit Immunoglobulin G (IgG) antibodies and using chromatography to separate bound and free colored label. OTC Test B was a lateral flow immunoassay dipstick containing mouse monoclonal anti-β-hCG antibody colloidal gold conjugate pre-dried on a pad, mouse monocolonal anti-α-hCG antibodies, and goat anti-mouse IgG. The POCT test employed mouse monoclonal anti-hCG antibodies and goat polyclonal anti-hCG antibodies. RESULTS: Among 14 pediatric patients who had undergone augmentation cystoplasty, 12 (85.7%) had positive pregnancy test results on OTC Test A, including all 9 females and 60% of males (n = 3/5; Table 1). No patients had positive pregnancy test results on OTC Test B or the POCT pregnancy test (Table 1). No false positive OTC pregnancy test results occurred among 4 patients with Mitrofanoff appendicovesicostomies only. Among patients with enterocystoplasties, UA results indicated that the majority had at least trace levels of protein, blood, and leukocytes, most tested positive for nitrite, and mean urine pH was 6.7 (±0.5; Table 1). CONCLUSIONS: Preliminary findings indicate that certain OTC pregnancy tests qualitatively assessing hCG in urine may be inaccurate among patients who have previously undergone augmentation enterocystoplasties. Female patients of reproductive age should be counseled regarding appropriate pregnancy testing options to avoid unplanned pregnancy scares or concerns about ectopic pregnancies. Source of Funding: The Long Road Foundation © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e157 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Zoë Baker More articles by this author Arthi Hannallah More articles by this author Hannah Dillon More articles by this author Yuding Wang More articles by this author Evalynn Vasquez More articles by this author Expand All Advertisement PDF DownloadLoading ...

To Be or Not to Be: Pregnant or Not

Background: Beta Human chorionic gonadotropin (β-hCG) is used for diagnosing pregnancy. Differential diagnosis for elevated β-hCG includes false positive test due to antibody interference, gestational trophoblastic disease (GTD), pituitary production of β-hCG or non-gestational malignancies including hepatic, neuroendocrine, breast, ovarian, pancreatic, cervical, and gastric cancers. We are presenting a case of a menopausal woman noted to have persistently positive serum pregnancy test. Case: 42-year-old female (G3 P2 A1) with a history of thyroid nodules and hypothyroidism was referred to endocrinology clinic for persistently positive serum pregnancy test without being pregnant. Last C-section delivery was 13 yrs ago. Last menstrual period was more than one year ago. Prior to that, her menstruation had always been irregular. Patient denied any spotting, pelvic discomfort/pain or weight loss in last few months. Seven months ago, POCT urine UCG test was done as per radiology protocol prior to CT abdomen for flank pain, and came back positive. Serum β-hCG was mildly positive at 4.3 (0.0 - 2.4 mIU/ml). Pelvic ultrasound did not show presence of a gestational sac. Repeat serum β-hCG level a week later was 3.8 mIU/ml. Patient was told she had early miscarriage. However, about 6 months later, PCP repeated serum β-hCG level and was elevated at 6.2 mIU/ml and thus patient was referred to endocrinology. Further work up showed FSH 61.3 (post-menopausal: 13.1-86.5 mIU/ml), prolactin 12.6 (3.0-18.6 ng/mL), TSH 9.41(0.47 - 4.70 uIU/ml) and estradiol level <15 pg/ml. β-hCG by dilution was ordered but was cancelled by lab for unknown reason. Patient was then also seen by OB-GYN who advised patient that she is menopausal and started her on estrogen-progesterone (E/P) therapy. About 4 weeks after starting E/P therapy, urine UCG came back negative. Hyper- glycosylated hCG (H-hCG) was not elevated. Patient was explained that false positive pregnancy test was due to pituitary production of β-hCG. Discussion: We propose considering following aspects when approaching a case of elevated β-hCG in absence of pregnancy. 1) Hook effect can mask very high level of β-hCG, repeating test after dilution will rule out hook effect. 2) Many case studies have shown pituitary production of β-hCG in perimenopausal women. Perimenopausal women 41-55 years of age with mildly elevated serum β-hCG levels (5.0-14.0 mIU/ml) and concomitant FSH level over 45.0 mIU/ml are likely to have pituitary production of β-hCG(1). If we can suppress β-hCG with two weeks of E/P therapy, this supports pituitary production of β-hCG. 3) If above testing is equivocal then one can consider checking H-hCG which is predominately secreted by the more invasive cytotrophoblastic cells, and supports diagnosis of GTD.

Reducing False-Positive Pregnancy Test Results in Patients With Cancer

To assess whether the use of a laboratory test specific for intact human chorionic gonadotropin (hCG) would reduce the number of false-positive pregnancy test results. From October 21, 2014, to January 20, 2015, and April 1, 2015, to June 2, 2015, all serum samples sent for pregnancy screening at a large cancer center with a value of 5 milli-international units/mL or greater total β-hCG were frozen and stored and then retested using intact hCG reagent. We compared the accuracy of total β-hCG and intact hCG results for the diagnosis of clinically confirmed pregnancy. A negative test was defined as 14 milli-international units/mL or less, our current institutional cutoff. We also assessed a cutoff of less than 5 milli-international units/mL, a historical cutoff to rule out pregnancy. We performed intact hCG testing on 64 patient samples, of which 34 had originally resulted positive when tested for total β-hCG. These included 21 cases of clinically confirmed pregnancy and 13 false-positive cases. No women were pregnant when their intact hCG concentration was 14 milli-international units/mL or less, and all pregnancies were detected at and above this concentration. Intact hCG reduced the number of false-positive pregnancy test results from 13 to 1, a 92% reduction (95% CI 64-99%), corresponding to a reduction in the false-positive rate from 38% (95% CI 22-56%) to 3% (95% CI 1-15%). The use of intact hCG reagent in patients with cancer reduces the rate of false-positive pregnancy test results without increasing the rate of false-negative test results.

Luteal phase GnRHa trigger in random start fertility preservation cycles

Depending on the type of cancer and how early the patient is referred before chemotherapy, there may nor may not be sufficient time to wait for the menstrual period to initiate ovarian stimulation for embryo or oocyte freezing. We have previously reported a “Random Start Controlled Ovarian Stimulation”(RSCOH) protocol where females with breast cancer were initiated on letrozole and gonadotropins followed by human chorionic gonadotropin (hCG) trigger, regardless of where they were in their menstrual cycle, even postovulation [5]. This approach resulted in a considerable number of oocytes and embryos. We have also reported previously that use of GnRHa trigger instead of hCG reduces ovarian hyperstimulation syndrome (OHSS) risks and estrogen exposure in letrozole-gonadotropin cycles [4]. OHSS may carry additional risks, as cancer patients are already prone to thromboembolic events. In addition, development of severe OHSS as well as hCG trigger-induced false positive pregnancy tests prior to initiation of chemotherapy may result in further delay of chemotherapy. Here we report an index case where the use of GnRHa trigger was tested in a luteal start COH (RSCOH)ovarian stimulation cycle which was initiated immediately after an LH surge.

False-positive urine pregnancy test in a woman with adenomysosis

We present a case of a 39-year-old woman presenting to the emergency department with persistent vaginal bleeding with myoma and endometrium thickness. The qualitative urine human chorionic gonadotropin (hCG) showed positive result, however, the quantitative serum hCG had negative result. The negative serum hCG result suggests that the false-positive result was not caused by elevated circulating hCG. According to the urine hCG one-step pregnancy device, 1 mg/dL of hemoglobin may not interference the pregnancy result. Nevertheless, we found that the hemoglobin level was 40 mg/dL in the urine specimen. We designed a in vitro experiment to evaluate the effects of hemoglobin on urine pregnancy test. The concentrations of hemoglobin from 5 to 500 mg/dL did not yield a positive urine pregnancy test. On the basis of our findings, the false positive pregnancy test was not caused by hemoglobin. It is important to confirm a suspected false-positive urine hCG test using a quantitative serum hCG test. Although it is not certain the mechanism for false positive reaction in this peculiar sample, the ACON urine hCG one-step pregnancy will occasionally yield a false-positive result in this class of patients.

Not even a little bit pregnant – ca colon as cause of false positive pregnancy test

<h3>Introduction</h3> Pregnancy testing is usually performed in women of reproductive age prior to any procedure which could potentially harm a developing embryo. Occasionally, false positive pregnancy tests may occur and have the potential to cause not only delay in treatment but also great consternation for the patient concerned. <h3>Patient</h3> A 38-year-old female with advanced colorectal carcinoma (Duke's stage 4) had serum beta human chorionic gonadotropin (hCG) tested prior to receiving chemotherapy. hCG was 74 IU/L which was interpreted as unambiguously positive. Chemotherapy was therefore delayed in spite of the patient believing she could not be pregnant. <h3>Investigations</h3> The luteinising hormone (LH) and follicle stimulating hormone (FSH) were normal for a woman of reproductive age. The initial result was confirmed on two alternate analysers and repeated 1 week later when it had risen to 84. Elimination of heterophile antibodies by use of Scantibodies and urine hCG confirmed the presence of free hCG. Performance of immunohistochemical staining of the original tumour collected 31 months earlier for hCG revealed patchy production of hCG in about 5% of the tumour population. This was seen predominantly at the advancing margin of the tumour. <h3>Discussion</h3> An hCG of 74 IU/L is normally considered unambiguously positive and the absence of heterophile antibodies or peri/post-menopausal source of pituitary hCG appeared to further increase the possibility of a normal or ectopic pregnancy. However the failure of the hCG to rise rapidly, a normal abdominal ultrasound and the protestations of the patient made further investigation necessary. The demonstration of hCG producing tumour tissue confirmed the likely origin of the circulating hCG. <h3>Conclusion</h3> Laboratories must be constantly aware of the common sources of false positive pregnancy tests including heterophile antibodies, ‘macro' hCG, pituitary hCG in peri/post menopausal women and tumour tissue itself. The production of hCG by germ cell tumours and teratomas is well recognised but the production by gastrointestinal cancers is much less well recognised. Recent reports suggest that non-trophoblastic tumours producing hCG are associated with a poor prognosis but a technique to stimulate anti-hCG antibodies may provide therapeutic promise.

A Little Bit Pregnant: Modeling How the Accurate Detection of Pregnancy Can Improve HIV Prevention Trials

The prevalence of unplanned pregnancies contributes to the methodological challenges of human immunodeficiency virus (HIV) prevention trials. In this paper, the authors discuss the incidence of pregnancy, including chemical pregnancy, and how the different methods of pregnancy diagnosis could affect the statistical power and calculated outcomes of HIV prevention trials. Study sample size inflation factors are estimated to aid in the design of clinical trials.The authors used published data of women attempting pregnancy as well as data from HPTN 055 (www.HPTN.org/research_studies/hptn055.asp) to estimate the percentage of early study discontinuation that would be associated with 3 diagnostic methods for pregnancy in a hypothetical clinical trial. They classified chemical pregnancies as false-positive pregnancy tests and showed the sample size adjustment that would be necessary in clinical trial design because of the early discontinuations associated with pregnancy. There is a greater than 3-fold difference in the number of falsely positive pregnancy tests that will be detected, depending upon the diagnostic method used. The number of incident pregnancies may render HIV prevention trial sample sizes inadequate by as much as 50%. Pregnancy prevention and precise pregnancy diagnosis are critical to the statistical power and integrity of HIV prevention trials.

False Positive Pregnancy Test Resulting from Passive Transfusion of beta-Human Chorionic Gonadotropin (bHCG) from Donor Red Blood Cells.

Blood products may contain donor-derived soluble factors such as allergens or antibodies, which when transfused, may cause pathology in the recipient or unexpected test results.Case: We describe a 16 year old female with hemoglobin SC disease who was referred for erythrocytapheresis to reduce the level of sickle hemoglobin prior to a surgical procedure that required general anesthesia. The patient was exchanged with five units of packed red blood cells (PRBC). The following day, routine pre-operative laboratory testing revealed an unexpected positive result in assays for beta subunit of human chorionic gonadotropin (bHCG), an early indicator of pregnancy. The patient denied sexually activity. The result caused postponement of the elective surgical procedure and prompted an abdominal ultrasound study to identify the source of bHCG, which was normal.Methods: Immunoassay was used to determine the bHCG level in the patient (Table 1) and in the residual plasma in each of the transfused units (Table 2).Conclusion: One blood donor, who was unaware of her pregnancy status at the time of donation, harbored a high bHCG level which caused the positive test results in the recipient patient's serum and urine. If an unexpected result is detected in a recipient of a blood transfusion, it is important to consider the possibility of passive transfusion of the analyte.Table 1:bHCG test results from recipient's blood following transfusion.TestResultNegative cut-offQualitative bHCG (serum)Positive< 10 mIU/mlQualitative bHCG (urine)Positive< 20 mIU/mlQuantititative bHCG (serum)9 mIU/ml< 5 mIU/mlTable 2:bHCG levels in the segments from the PRBC units transfused.Unit numberbHCG, mIU/ml*10.3920.713>1000**40.1850.24*Negative cut-off, <5 mIU/ml; **Exceeds the dynamic range (0–1000 mIU/ml) of qualitative bHCG assay.

Thalidomide Use in the US

In 1998, thalidomide (Thalomid), a known human teratogen, was approved by the US FDA for the treatment of erythema nodosum leprosum. To prevent fetal exposure to thalidomide, a restricted distribution risk management programme, the System for Thalidomide Education and Prescribing Safety (S.T.E.P.S.), was implemented. All clinicians, pharmacists and patients who prescribe, dispense and receive thalidomide, respectively, are required to enroll in S.T.E.P.S. Sexually active females of childbearing potential must use two methods of birth control before, during and after treatment. These patients must also have a negative pregnancy test within 24 hours before beginning therapy and periodically while on therapy. The objective of this report is to summarise the patterns of thalidomide use and to describe the occurrence of positive pregnancy tests in females of childbearing potential while they were using thalidomide in the S.T.E.P.S. programme in the US. A retrospective review of patients receiving thalidomide within the S.T.E.P.S. programme from September 1998 to 31 December 2004 to determine the occurrence of positive pregnancy tests whilst on treatment. Approximately 124,000 (43% female) patients were registered within the S.T.E.P.S. programme between September 1998 and 31 December 2004. Approximately 6,000 patients were females of childbearing potential, representing 5% of all patients and 11% of all female patients. Between 30 July 2001 and 31 December 2004, >88% of thalidomide use was for oncological conditions. There were 72 females of childbearing potential who had positive pregnancy tests. Sixty-nine of these patients had false positive pregnancy tests. Of the remaining three, one woman was pregnant while on thalidomide. This patient had an initial negative test and received thalidomide. Therapy was stopped when she had a positive pregnancy test. This pregnancy resulted in a miscarriage. Two additional patients were determined to be pregnant before receiving thalidomide. The S.T.E.P.S. programme is critical to managing the risks of thalidomide-associated teratogenicity. Sustained vigilance among health care providers and patients receiving thalidomide is essential to its continued success. Health care providers should be aware of the occurrence of false-positive pregnancy tests in females of childbearing potential receiving thalidomide.

False-positive urine β-HCG in a woman with a tubo-ovarian abscess

Modern urine β-human chorionic gonadotropin (HCG) assays that use enzyme-linked immunosorbent assay (ELISA) technology are sensitive and specific for diagnosing pregnancy, both intrauterine and ectopic, and have become indispensable to the practice of Emergency Medicine. A urine HCG test is often relied on by the Emergency Physician as a critical component in the diagnostic regimen of a patient with a possible ectopic pregnancy. We report a case of a false-positive urine β-HCG test in a patient with a ruptured tubo-ovarian abscess. Though false-positive pregnancy tests with tubo-ovarian abscesses have previously been reported with older methods of HCG detection, we believe that this is the first case where the pregnancy test was the modern ELISA type. The mechanism for the false-positive reaction in this case is unknown, but time may show that the ELISA test kit, like its predecessors, may occasionally give a false-positive reaction in this class of patients.

False-positive pregnancy test associated with gonadoblastoma

Gonadoblastomas are known to be hormonally active tumors that occur in streak or dysgenetic gonads of patients with intersex abnormalities. Several reports document their ability to produce beta-human chorionic gonadotropin (HCG), but none have documented an elevated peripheral serum beta-HCG. We report on the case of a patient with pure gonadal dysgenesis with XY karyotype who was found to have an elevated peripheral serum beta-HCG after a positive pregnancy test. Knowledge of gonadoblastoma’s potential to elevate serum beta-HCG levels may prevent unnecessary searches for other causes.

Preoperative Pregnancy Testing in Ambulatory Surgery

Ian Lewis, M.B., B.S., M.R.C.P., F.R.C.A., Consultant in Anesthesiology.Jonathan Cooper, M.B., B.S., F.R.C.A., Senior Registrar in Anesthesiology, Shackleton Department of Anaesthetics, Level E, Center Block, Southampton University Hospital, Tremona Road, Southampton, SO 16 6YD, United Kingdom.To the Editor:--Manley et al. [1]found the true incidence of previously unrecognized pregnancy in menstruating women presenting for elective ambulatory surgery to be 7 of 2,056 (0.3%), as determined by urinary or serum human chorionic gonadotrophin immunoassay. Although this information is valuable, alone it is insufficient for the clinician to evaluate the significance of a positive or negative pregnancy test result in a single patient.The probability of pregnancy in a patient with a positive test result (positive predictive value) equals the number of true positives divided by the total number of positives (true positives + false positives); the probability of nonpregnancy in a patient with a negative test result (negative predictive value) equals the number of true negatives divided by the total number of negatives (true negatives + false negatives). The clinical significance of the pregnancy test is therefore given by the positive predictive and the negative predictive values. These values can be calculated from intrinsic properties of the test (sensitivity and specificity) and the estimated prevalence of pregnancy in the population in question. [2,3].Manley et al. [1]quote one false-positive pregnancy test among 179 adolescent women (0.6%) during preoperative testing from data by Malviya et al. [4]The specificity of the pregnancy test is therefore 178 of 179, 99.4%. Manley et al. [1]also state that the possibility of a false-negative result (pregnancy despite a negative test result) is "extremely remote." Let us assume, therefore, that the sensitivity of the test is 100% (a sensitivity of 99% would give virtually the same result in the following discussion).Consider a sample of 100,000 menstruating women presenting for elective ambulatory surgery. Given the original findings by Manley et al. [1]of a 0.3% pregnancy rate, there would be 300 pregnant and 99,700 nonpregnant women in the sample. Pregnancy testing of the 300 pregnant women would result in 300 true positives and no false negatives (100% sensitivity); pregnancy testing of the 99,700 nonpregnant women would result in 99,102 true negatives and 598 false positives (99.4% specificity). The positive predictive value is 300/300 + 598 = 33%, and the negative predictive value is 99,102/99,102 + 0 = 100%.Given that the aforementioned assumptions are valid, the clinician can be virtually 100% confident that a negative preoperative pregnancy test means that the patient is not pregnant. On the other hand, only 33% of women who test positive will be pregnant; the remaining 67% will have their surgery delayed but will not be pregnant. The latter statement is based on the specificity derived from data by Malviya et al. [4]Even if this assumption is not valid, when a population has a low overall prevalence of pregnancy (0.3% in this example), it is essential for the pregnancy test to be highly specific (few false positives) if a low positive predictive value is to be avoided. Improving the specificity to 99.95% (a false-positive rate of 1 in 2,000) would only result in an 86% positive predictive value given the same prevalence of pregnancy (0.3%).Although Manley et al. [1]and Malviya et al. [4]found what appear to be minor differences in specificity for preoperative pregnancy testing, the low prevalence of pregnancy in the population to be tested will result in large differences in positive predictive values. More data are required, preferably from large samples of women, before we can judge the clinical usefulness of preoperative pregnancy testing.Ian Lewis, M.B., B.S., M.R.C.P., F.R.C.A., Consultant in Anesthesiology.Jonathan Cooper, M.B., B.S., F.R.C.A., Senior Registrar in Anesthesiology, Shackleton Department of Anaesthetics, Level E, Center Block, Southampton University Hospital, Tremona Road, Southampton, SO 16 6YD, United Kingdom.

Bronchogenic Carcinoma Presenting as a Pseudopregnancy

I read with interest the report of a patient with bronchogenic carcinoma presenting as a pseudopregnancy, which was in the February issue (CHEST 1995; 107:567-69). We have recently reported about two women in their 40s who presented with breast engorgement, false-positive pregnancy, and ectopic gonadotropin production due to bronchogenic carcinoma. 1 Snyder RW Pickens PV Kukora JS. Breast engorgement and false-positive pregnancy tests due to lung cancer with ectopic gonadotrophin production.. Am Surg. 1995; 4: 328-329 Google Scholar Pregnancy was suspected in one of the patients because of her irregular menstrual cycle. Intensive evaluation did reveal an otherwise occult bronchogenic carcinoma. Pathologic examination revealed positive immunoperoxidase stain for ß-HCG. After surgical resection, ß-HCG dropped to normal with apparent cure after 4 years of monitoring.

False-positive pregnancy test

Journal Article False-positive pregnancy test Get access G Planet G Planet Search for other works by this author on: Oxford Academic Google Scholar Clinical Chemistry, Volume 36, Issue 8, 1 August 1990, Pages 1522–1523, https://doi.org/10.1093/clinchem/36.8.1522 Published: 01 August 1990

Heterophilic antibodies interfering with radioimmunoassay. A false-positive pregnancy test

Heterophilic antibodies interfering with radioimmunoassay. A false-positive pregnancy test

Heterophilic Antibodies Interfering With Radioimmunoassay

A young man with amenorrhea had a consistently positive pregnancy test result (serum radioimmunoassay measurement of beta-human chorionic gonadotropin hormone). No fetal or placental tissue was found after uterine curettage and exploratory laparotomy. The false-positive pregnancy test result was due to heterophilic antibovine and antigoat antibodies in the patient's serum. These antibodies interfered with radioimmunoassays using goat antibodies. This case shows that serum heterophilic antibodies can interfere with immunoassays and result in unnecessary diagnostic procedures and/or unnecessary treatment.

Interactions of CNS Drugs: Psychotherapeutic Agents—The Antipsychotic Drugs

Aspects of the pharmacology of the phenothiazine antipsychotic agents pertinent to possible interactions are reviewed. Pharmacokinetic interactions of possible clinical importance are the interference with the absorption of the phenothiazines by antacids, reversal of the hypotensive effect of guanethidine by psychotropic drugs, blockade of the effects of levodopa in Parkinson's disease, and stimulation of phenothiazine-metabolizing enzymes by phenobarbital. Pharmacologically, phenothiazines may potentiate certain depressant effects of other CNS depressants or add to the anticholinergic side effects of a number of other drugs. The phenothiazines appear to antagonize both the CNS stimulant and the anorexic effects of amphetamines and related substances. Other reactions of possible concern are the phenothiazine-induced hypoglycemia, the relationship of lithium toxicity to sodium intake, and the number of false positive pregnancy tests in patients on phenothiazine therapy.

Primary hepatic malignancy in pregnant women

Three women dying from hepatic carcinoma during pregnancy are presented. One of these women with a hepatocellular carcinoma had alpha fetoprotein in the serum and antibody to hepatitis B antigen. A fourth patient died 2 months post partum with a cholangiocarcinoma. A false positive pregnancy test suggested that she had metastatic choriocarcinoma in the liver, and a panhysterectomy was performed. The clinical diagnosis with the use of alpha fetoprotein and chorionic gonadotropin for detection of hepatoma and the etiopathogenesis of primary hepatic malignancy in pregnancy are discussed.