Primary Immunodeficiency Diseases in Latin America: First Report from Eight Countries Participating in the LAGID

The Latin American Group for Primary Immunodeficiencies, formed in 1993, presently includes 12 countries. One goal was to study the frequency of primary immunodeficiencies in various regions of the American continent and to enhance knowledge about these diseases among primary-care physicians, as well as allergist–immunologists. Important for this purpose was the development of a registry of primary immunodeficiencies using a uniform questionnaire and computerized database. To date, eight countries have collected information on a total of 1428 patients. Predominantly antibody deficiencies were reported in 58% of patients, followed by cellular and antibody immunodeficiencies associated with other abnormalities in 18%, immunodeficiency syndromes associated with granulocyte dysfunction in 8%, phagocytic disorders in 9%, combined cellular and antibody immunodeficiencies in 5%, and complement deficiencies in 2% of patients. The information gathered from this initial analysis of data will serve to expand the patient database to more areas within participating countries and to new countries and to increase collaboration toward better diagnosis and treatment of these diseases.     

Pulmonary and mediastinal "sarcoidosis" following surgical resection of cancer

Previous reports indicate that enlarged hilar and mediastinal lymph nodes caused by sarcoid-like reactions may develop after curative resection of cancer, and their presence does not necessarily denote neoplastic recurrence. Reports further suggest that coexisting pulmonary infiltrates in this setting may be related to sarcoidosis. In this study, we describe two patients who had resected lung and gastric cancer and who later developed pulmonary interstitial infiltrate, concurrent with progressive mediastinal lymphadenopathy initially thought to be caused by intrathoracic dissemination of their cancer. These changes were shown by open lung biopsy to be a benign, granulomatous reaction interpreted as sarcoidosis. Thus, it is important to recognize this clinical pattern when pulmonary infiltrates develop after complete treatment of cancer in an otherwise relapse-free patient and to encourage lung or lymph node biopsy in these particular settings in order to confirm a sarcoid-like reaction, thereby avoiding unnecessary chemotherapy for presumed tumor recurrence.     

Episodic nocturnal wanderings in non-epileptic young patients

Twelve patients, aged 19 to 29 years, presented with episodic nocturnal wanderings characterized by stereotyped frequent attacks of screaming, ambulation, and complex automatisms during sleep. The attacks ranged in frequency from two or three per year to several per night and were often associated with semi-purposeful violent and even life-threatening behavior. None of the patients had a history of seizures; three had a history of prior parasomnias and four had family members with a history of parasomnia. Polysomnographic and daytime electroencephalographic (EEG) investigations showed potentially epileptiform activity in four patients. Recorded episodes were not accompanied by ictal EEG activity. Anticonvulsant medication reduced or eliminated the attacks in all of the nine treated patients. The pathophysiology of the disorder is uncertain.     

Endoscopic ultrasound-guided fine-needle aspiration cytology of peripheral nerve-sheath tumors

Endoscopic ultrasound (EUS) has allowed for the fine-needle aspiration and diagnosis of many different gastrointestinal neoplasms, including mesenchymal tumors. Although most mesenchymal tumors of the gastrointestinal tract are gastrointestinal stromal tumors (GISTs), other mesenchymal tumors, including neural tumors, do occur. Proper diagnosis and differentiation of these tumors from GISTs are important because of their different prognoses and treatment regimens. We encountered three peripheral nerve-sheath tumors of the gastrointestinal tract aspirated by EUS (two schwannomas and a granular-cell tumor). We report on the endoscopic ultrasound, cytologic, histologic, and immunohistochemical findings of these cases.     

Aetiology of congenital absence of vas deferens: genetic study of three generations

Bilateral congenital absence of the vas deferens (CAVD) is aform of male sterility (found in otherwise normal men) of unknownaetiology. Because males with cystic fibrosis (CF) almost invariablyhave CAVD as well, we investigated the hypothesis that men withisolated CAVD might share a common genetic background with maleswith CF. Genetic testing for CF was carried out in three generationsof subjects: 44 patients with CAVD and their wives, 24 of theirparents, and 13 of their offspring generated by microsurgicalepididymal sperm aspiration (MESA) and in-vitro fertilization(IVF). DNA extracted from peripheral lymphocytes was amplifiedby the polymerase chain reaction (PCR) and then analysed for12 mutations in the cystic fibrosis transmembrane conductanceregulatory (CFTR) gene. Among 44 patients tested with CAVD,26 (59%) were positive for at least one CF mutation, while thecarrier frequency for CF mutations in the general populationis only 4%. Four patients were found to be compound heterozygotes,three with genotypes Delta F-508/R117H, one with R553X/R117H.Among 24 parents tested, 15 (seven fathers, eight mothers) hadsons with CAVD who were positive for CF mutations. Of these,nine (four fathers and five mothers) were found to be carriersfor CF mutations. These four fathers, although carriers of CFmutations, were obviously fertile. Of the 13 offspring tested,six (three boys and three girls) had CF positive fathers. Ofthese, three (two girls and one boy) were found to be carriersfor CF mutations. These MESA/IVF children are the first offpsringto whom men with CAVD have been able to transmit CF mutations.All of the MESA/IVF male offspring (like their grandfathers)had a normal vas deferens bilaterally, including one carrierfor Delta F-508. This study revealed, by genetic testing ofotherwise normal men with sterility caused by CAVD, a new populationof patients with a variant form of CF and highlighted the possibilitythat carrier frequency for CF is higher than previously thought.Compound heterozygosity for CF mutations and not carrier conditionis associated with isolated CAVD. It is concluded that geneticcounselling and screening for CF should be offered to couplesundergoing sperm aspiration and IVF procedures when CAVD isa factor in their infertility.     

Effects of overexpansion on stents' recoil, symmetry/asymmetry, and neointimal hyperplasia in aortas of hypercholesterolemic rabbits.

BACKGROUND: It is not known whether overexpansion modifies stent recoil, symmetric distribution of struts, and neointimal hyperplasia. OBJECTIVES: The objectives were (a) to evaluate whether stent overexpansion modifies the geometric configuration of the stent in the arterial wall, (b) to determine the relationship between overexpansion and stent recoil, and (c) to evaluate the relationship between the distribution of struts and neointimal hyperplasia. METHODS: Twenty tubular stainless steel 316L stents (3.0 and 3.5 mm in diameter) were implanted at 20 and 10 atm, respectively, in the abdominal aorta of New Zealand rabbits fed a hypercholesterolemic diet (1% cholesterol). Sham operations were also performed in seven animals. Eight weeks after implantation or sham operation, an intravascular ultrasound (IVUS) study was performed to measure stent recoil and aid in stent classification (symmetric or asymmetric) according to strut distribution. The degree of injury and neointimal hyperplasia were also evaluated in hematoxylin-eosin stained sections. RESULTS: The symmetry/asymmetry of stents assessed by IVUS, as well as the neointimal hyperplasia, was similar in both groups. Stent recoil was significantly greater in the 3.0-mm stent (overexpanded) group (0.28+/-0.02 mm), as compared with stent recoil in the 3.5-mm stent group (0.10+/-0.01 mm, P<.05). The neointimal hyperplasia in histological slices, independent of the implant technique, was predominantly in zones with higher strut concentration as compared with zones with fewer struts. CONCLUSIONS: Stent overexpansion enhanced stent recoil and did not modify symmetric and asymmetric strut distribution. Neointimal hyperplasia was not modified by the implant technique. Interestingly, significant hyperplasia was observed in locations with greater strut concentration, independent of overexpansion.     

Late denervation in patients with antecedent paralytic poliomyelitis

The development of new weakness, fatigue, and pain decades after acute paralytic poliomyelitis is a recognized syndrome. We conducted a controlled study of this syndrome by analyzing clinical, electromyographic, and muscle-biopsy features in 18 patients with a history of poliomyelitis--13 reporting 1 to 20 years of new weakness and 5 without new symptoms. The patients with new weakness also reported new muscle atrophy (9 of 13) and fatigue (10 of 13), symptoms not reported by the controls. The age at the time of acute poliomyelitis, severity of poliomyelitis, residual disability, number of years since acute poliomyelitis, and age at the time of study were comparable in the weakening and control groups. Evidence of remote denervation consistent with antecedent poliomyelitis was demonstrated in all patients by electromyography or muscle biopsy or both. In addition, active denervation (as evidenced by spontaneous activity on conventional electromyography, increased jitter on single-fiber electromyography, or atrophic myofibers) was found in 12 patients in the weakening group and in all 5 controls. Immunohistochemical detection of myofibers expressing the neural-cell adhesion molecule corroborated ongoing denervation in both patient groups. When muscle data from both groups were pooled, correlations were observed between the extent of past reinnervation and the degree of ongoing motor-unit instability. We conclude that the extensive reinnervation of denervated muscle that occurs in paralytic poliomyelitis may be followed by late denervation of the previously reinnervated muscle fibers. Electromyographic and muscle-biopsy evidence of ongoing denervation does not distinguish between stable patients with prior paralytic poliomyelitis and those with new weakness.