Heterophilic antibodies may be a cause of falsely low total IGF1 levels

BACKGROUND

A low serum total IGF1 is considered as a diagnostic indicator of GH deficiency (GHD) in the presence of hypopituitarism. Introduction of IRMA and chemiluminescent immunometric assay (CLIA) IGF1 immunoassays has introduced endogenous antibodies as a new source of interference. In general, this goes unnoticed and might lead to unnecessary diagnostic and therapeutic interventions.

CASE

A 56-year-old man was referred with a decline in physical performance, unexplained osteopenia, and weight loss of 3 kg over the past 8 months. Although clinical signs and symptoms were unremarkable, laboratory results pointed to secondary hypothyroidism and secondary hypogonadism. In addition, the serum total IGF1 level (CLIA; Siemens Medical Solutions Diagnostics) was in the low normal range. Two GH stimulation tests were performed, but these tests did not support the diagnosis GHD. Moreover, IGF1 bioactivity measured by the kinase receptor activation assay was normal. Interference of heterophilic antibodies was considered. After pretreatment with specific heterophilic blocking tubes that contain blocking reagents to eliminate heterophilic antibodies, serum-free thyroxine, testosterone, and IGF1 levels turned out to be normal.

CONCLUSION

To the best of our knowledge, we here describe the first case in the literature of a patient with low serum total IGF1 levels due to interference from heterophilic antibodies in the used IGF1 immunoassay. When confronted with low-IGF1 levels that do not fit the clinical picture, interference of heterophilic antibodies should be considered in the differential diagnosis.

[Diagnostic image (349). A woman with flushes]

A 57-year-old woman suffered from frequent flushes due to an ovarian carcinoid tumour.

Paraneoplastic hypertrichosis lanuginosa acquisita: uncommon or overlooked?

Acquired hypertrichosis lanugo-type or hypertrichosis lanuginosa acquisita (HLA) is often associated with metabolic and endocrine disorders and use of certain drugs. The occurrence of HLA with malignancy was first noted in 1865, and it has since been described in 56 patients as a paraneoplastic syndrome both in women and in men. Sometimes HLA occurs concurrent with acanthosis nigricans, papillary hypertrophy of the tongue, and glossitis. The predominance of female cases is striking. Malignancy-associated HLA seems to occur especially in the age group 40-70 years. In women with HLA the most frequent malignancy is colorectal cancer, followed in order by lung cancer and breast cancer; in men lung cancer is the malignancy most frequently associated with HLA, followed by colorectal cancer. In 3 years we saw 10 patients with HLA, in whom the malignancy was usually metastasized. Only one patient had local disease; after removal of the primary tumour it took 2 years before the lanugo hair recurred. The aetiology of the syndrome is not clear: no specific hormonal or biochemical abnormalities have been identified as yet. The difference between hirsutism and lanugo-type hypertrichosis is discussed. It is stressed that the appearance of lanugo-type hypertrichosis in body areas previously perceived by patients as 'hairless' is highly indicative of internal malignancy.

[Sustained weight loss 2 years after laparoscopic adjustable gastric banding for morbid obesity]

OBJECTIVE

To analyse the results of the laparoscopic adjustable gastric banding (LAGB) procedure for morbid obesity. DESIGN. Retrospective, descriptive.

METHOD

From November 1, 1995 to May 31, 2005, laparoscopic adjustable banding surgery was performed in St. Antonius Hospital, Nieuwegein, the Netherlands, in 411 patients. Inclusion criteria were BMI > or = 40 kg/ m(2) or BMI > 35 kg/m(2) and severe comorbidity with > 3 attempts at weight loss in the past. Selection, inclusion and follow-up were performed in a specialised, multidisciplinary setting. Height, weight, and complications were prospectively recorded. In 1995-2000 the perigastric surgical procedure was used and in 2000-2005 the pars-flaccida method.

RESULTS

The study group consisted of 350 (85%) women and 61 (I5%) men with a median age of 38 years (range 17-60). Out of these 411 patients, the median weight was 133.4 kg, the median overweight, 69.6 kg and the median BMI 46.3 kg/m2. Two years after surgery, data was known for 267 patients where 206 (77%) had a weight loss > 30%, and 7 patients (3%) a weight gain. The median BMI difference was then -10.2 kg/m2 (range +4.7--26.4). The median loss of overweight was 46.3% (+10.00--97.8). The weight loss remained stable in the following years. The most commonly seen complications were fundus slippage (13%) and port-a-cath related complications (7%). These occurred more often in patients who had had the perigastric method surgery than in the parsflaccida surgical method.

CONCLUSION

Three quarters of the patients with morbid obesity who received laparoscopic gastric banding surgery had achieved and sustained weight loss at 2 years following surgery. The pars-flaccida method resulted in fewer complications than the perigastric surgical method.

[Diagnostic image (303). A deeply tanned woman]

A 50-year-old woman complained of nausea, diarrhoea, tiredness and dizziness five weeks after a visit to Egypt. She was deeply tanned with hyperpigmentation on the metacarpophalangeal joints, palm of hand creases and buccal mucosa, due to Addison's disease.

Randomised Phase III study of biweekly 24-h infusion of high-dose 5FU with folinic acid and oxaliplatin versus monthly plus 5-FU/folinic acid in first-line treatment of advanced colorectal cancer

BACKGROUND

A phase III study was started to compare oxaliplatin/5FU/LV in the first-line with bolus FU/LV in metastatic colorectal cancer.

PATIENTS AND METHODS

302 patients were randomised and received bolus 5-FU 425 mg/m(2) day 1-5, FA 20 mg/m(2) day 1-5, q 4 wk or oxaliplatin 85 mg/m(2), 2 h-infusion, FA 200 mg/m(2), 1-h infusion. 5-FU 2600 mg/m(2), 24-h infusion day 1, q 2 wk. The primary endpoint was response rate (RR).

RESULTS

The median follow-up is 31.8 months, 90.4% of the patients have died. Confirmed RR, progression free survival (PFS; months) and median overall survival (OS; months) in 5FU/LV versus 5FU/LV/oxaliplatin were respectively 18.5% versus (vs) 33.8% (P = 0.004), 5.6 vs 6.7 (P = 0.016) and 13.3 vs 13.8 (P = 0.619). In the 5FU/LV/oxaliplatin arm less grade (3/4) toxicity was measured for diarrhoea, stomatitis, an increase in idiosyncratic side effects and neurosensory events compared with 5FU/LV. The quality of life (QOL) was equal in both arms. Second line treatment was given in 62% of the patients, crossover of 5FU/LV to 5FU/LV/oxaliplatin occurred in 14%.

CONCLUSIONS

Oxaliplatin in the first-line resulted in an increased RR and PFS with less grade 3/4 mucositis/diarrhoea compared with 5FU/LV alone. Idiosyncratic side effects deserve attention with oxaliplatin. Despite a low treatment cross over rate, OS in both groups was comparable.

[Delayed recognition of falciparum malaria from a non-endemic region in the Dominican Republic]

A 28-year-old patient had suffered from fever, headache, abdominal pains and vomiting for the past three weeks. She had visited a region in the Dominican Republic where the risk of malaria is considered to be low. The complaints were initially regarded as a viral infection. Later, however, she was found to have severe falciparum malaria. She recovered completely following antibiotic therapy. Since November 2004, 17 cases of falciparum malaria have been reported world-wide among travellers to non-endemic regions in the Dominican Republic. Physicians should always consider the possibility of malaria in travellers because a timely diagnosis of falciparum malaria can be of vital importance.

Phase III trial of satraplatin, an oral platinum plus prednisone vs. prednisone alone in patients with hormone-refractory prostate cancer

Satraplatin is a novel oral platinum (IV) complex that shows activity against hormone-refractory prostate cancer (HRPC) in cisplatin-resistant human tumor lines in phase I and phase II trials. A randomized multicenter phase III trial with a target sample size of 380 patients was initiated in men with HRPC. After 50 randomized patients, the trial was closed to further accrual by the sponsoring company. An ad hoc analysis of all available data is reported here. Eligibility criteria included pathological proof of prostate cancer, documented progression despite prior hormonal manipulation, WHO PS 0-2, and no daily intake of narcotic analgesics. Patients were randomized between satraplatin 100 mg/m(2) for 5 days plus prednisone 10 mg orally BID or prednisone alone. Compliance was excellent. 48/50 patients have progressed and 42 have died, mostly due to prostate cancer. Median overall survival was 14.9 months (95% CI: 13.7-28.4) on the satraplatin plus prednisone arm and 11.9 months (95% CI: 8.4-23.1) on prednisone alone (hazard ratio, HR = 0.84, 95% CI: 0.46-1.55). A >50% decrease in prostrate specific antigen (PSA) was seen in 9/27 (33.3%) in the satraplatin plus prednisone arm vs. 2/23 (8.7%) on the prednisone alone arm. Progression-free survival was 5.2 months (95% CI: 2.8-13.7) on the satraplatin plus prednisone arm as compared to 2.5 months (95% CI: 2.1- 4.7) on the prednisone alone arm (HR = 0.50, 95% CI: 0.28-0.92). This difference is statistically significant (p = 0.023). Toxicity was generally minimal in both arms. This randomized comparison of a combination of satraplatin and prednisone versus prednisone alone supports the antitumor activity of the combination. Its role in the treatment of HPRC remains to be elucidated in an appropriate phase III setting.

A phase I dose-escalating study of docetaxel plus folinic acid and 5-fluorouracil in anthracycline-pretreated patients with metastatic breast cancer

BACKGROUND

Since the need for nonanthracycline-containing chemotherapy regimens increases with the increased use of anthracyclines in earlier stages of breast cancer, we investigated the feasibility of the combination of docetaxel and 5-fluorouracil (5-FU) with folinic acid (FA).

PATIENTS AND METHODS

Anthracycline-pretreated patients with metastatic breast cancer were eligible. Docetaxel was administered as a one-hour infusion every three weeks on day 1, FA 500 mg/m2 (fixed dose) as a two-hour infusion on days 1 and 15 and 5-FU as a 24-hour infusion on days 1 and 15. The dose levels tested were (docetaxel/5FU in mg/m2): 60/1800, 75/1800, 85/1800, 100/1800, and 100/2100.

RESULTS

Altogether 28 patients were accrued and treated in this multicentre open-label study. Dose-limiting toxicities (DLTs) were not observed at dose level I, and in two patients in each of the higher dose levels. DLTs observed were grade III/IV infection (n=4), febrile neutropenia (n=2), diarrhoea (n=1) and erythema (n=1). Partial responses were observed in 10 out of 24 evaluable patients (42%, 95% confidence interval 22.1 to 63.4%). Dose escalation beyond the highest dose level (100/2100) was deemed inappropriate, because these dose levels correspond to recommended dose levels for each drug as a single agent.

CONCLUSION

Combination of docetaxel (100 mg/m2, one-hour infusion q3 weeks on day 1), FA (500 mg/m2, two-hour infusion on days 1 and 15) and 5-FU (2100 mg/m2, 24-hour infusion on days 1 and 15) is a feasible regimen with encouraging activity in anthracycline-pretreated patients.

[Metabolic disregulation after starting feeding: "refeeding" syndrome: the central role of phosphate]

A 47-year-old man was admitted due to serious weight loss after several months in which he had not eaten and had drunk almost solely beer. Shortly after the start of enteral tube feeding, the patient developed serious heart failure. This was associated with severely disrupted electrolyte levels and in particular hypophosphataemia and hypomagnesaemia. This condition is termed refeeding syndrome. The circulating volume increases due to the hyperinsulinaemia which occurs during the feeding phase. Furthermore a shortage of ATP occurs and the heart may fail. In efforts to establish feeding, a weight increase of not more than 1 kg per week should be attempted; if the weight increases by more than this, then fluid retention is the probable cause.

Vasculitis due to gemcitabine

We report the first occurrence of gemcitabine-induced vasculitis. It concerns a 45-year-old man diagnosed with non-small lung cancer since 2 months. After the first cycle of chemotherapy, consisting of gemcitabine and cisplatin, he developed myalgia and swelling of arms and legs with impairment of movement. This re-occurred during the second cycle of chemotherapy. Further anemia, elevated ESR and increased creatininephosphokinase. A surgical biopsy showed leucocytoclastic vasculitis and necrosis of muscle tissue. The chemotherapy was stopped and the complaints disappeared and did not return.

[Diagnostic image (71). A woman with obesity, diabetes mellitus and use of corticosteroids. Mediastinal lipomatosis]

In a 69-year-old obese woman on prednisone treatment for temporal arteritis a widened mediastinum on chest X-ray proved to be mediastinal lipomatosis on CT-scan.